Merge pull request #2593 from dpalou/MOBILE-2272

Mobile 2272

scripts/langindex.json

@@ -1861,6 +1861,7 @@
   "core.mainmenu.help": "moodle",
   "core.mainmenu.logout": "moodle",
   "core.mainmenu.website": "local_moodlemobileapp",
+  "core.maxfilesize": "moodle",
   "core.maxsizeandattachments": "moodle",
   "core.min": "moodle",
   "core.mins": "moodle",
@@ -1944,8 +1945,8 @@
   "core.question.certainty": "qbehaviour_deferredcbm",
   "core.question.complete": "question",
   "core.question.correct": "question",
-  "core.question.errorattachmentsnotsupported": "local_moodlemobileapp",
+  "core.question.errorattachmentsnotsupportedinsite": "local_moodlemobileapp",
-  "core.question.errorinlinefilesnotsupported": "local_moodlemobileapp",
+  "core.question.errorembeddedfilesnotsupportedinsite": "local_moodlemobileapp",
   "core.question.errorquestionnotsupported": "local_moodlemobileapp",
   "core.question.feedback": "question",
   "core.question.howtodraganddrop": "local_moodlemobileapp",

src/addon/mod/lesson/providers/lesson-sync.ts

@@ -411,7 +411,7 @@ export class AddonModLessonSyncProvider extends CoreCourseActivitySyncBaseProvid
                                 const params = this.urlUtils.extractUrlParams(response.data.reviewlesson.value);
                                 if (params && params.pageid) {
                                     // The retake can be reviewed, mark it as finished. Don't block the user for this.
-                                    this.setRetakeFinishedInSync(lessonId, retake.retake, params.pageid, siteId);
+                                    this.setRetakeFinishedInSync(lessonId, retake.retake, Number(params.pageid), siteId);
                                 }
                             }
                         }

src/addon/mod/quiz/pages/player/player.ts

@@ -569,7 +569,8 @@ export class AddonModQuizPlayerPage implements OnInit, OnDestroy {
 
     // Prepare the answers to be sent for the attempt.
     protected prepareAnswers(): Promise<any> {
-        return this.questionHelper.prepareAnswers(this.questions, this.getAnswers(), this.offline);
+        return this.questionHelper.prepareAnswers(this.questions, this.getAnswers(), this.offline, this.component,
+                this.quiz.coursemodule);
     }
 
     /**
@@ -612,6 +613,8 @@ export class AddonModQuizPlayerPage implements OnInit, OnDestroy {
             if (this.formElement) {
                 this.domUtils.triggerFormSubmittedEvent(this.formElement, !this.offline, this.sitesProvider.getCurrentSiteId());
             }
+
+            return this.questionHelper.clearTmpData(this.questions, this.component, this.quiz.coursemodule);
         });
     }
 

src/addon/mod/quiz/providers/quiz-offline.ts

@@ -342,8 +342,8 @@ export class AddonModQuizOfflineProvider {
         for (const slot in questionsWithAnswers) {
             const question = questionsWithAnswers[slot];
 
-            promises.push(this.behaviourDelegate.determineNewState(
+            promises.push(this.behaviourDelegate.determineNewState(quiz.preferredbehaviour, AddonModQuizProvider.COMPONENT,
-                        quiz.preferredbehaviour, AddonModQuizProvider.COMPONENT, attempt.id, question, siteId).then((state) => {
+                    attempt.id, question, quiz.coursemodule, siteId).then((state) => {
                 // Check if state has changed.
                 if (state && state.name != question.state) {
                     newStates[question.slot] = state.name;

src/addon/mod/quiz/providers/quiz-sync.ts

@@ -21,6 +21,7 @@ import { CoreSitesProvider, CoreSitesReadingStrategy } from '@providers/sites';
 import { CoreSyncProvider } from '@providers/sync';
 import { CoreTextUtilsProvider } from '@providers/utils/text';
 import { CoreTimeUtilsProvider } from '@providers/utils/time';
+import { CoreUtils } from '@providers/utils/utils';
 import { CoreCourseProvider } from '@core/course/providers/course';
 import { CoreCourseLogHelperProvider } from '@core/course/providers/log-helper';
 import { CoreCourseModulePrefetchDelegate } from '@core/course/providers/module-prefetch-delegate';
@@ -77,25 +78,33 @@ export class AddonModQuizSyncProvider extends CoreCourseActivitySyncBaseProvider
      * @param quiz Quiz.
      * @param courseId Course ID.
      * @param warnings List of warnings generated by the sync.
-     * @param attemptId Last attempt ID.
+     * @param options Other options.
-     * @param offlineAttempt Offline attempt synchronized, if any.
-     * @param onlineAttempt Online data for the offline attempt.
-     * @param removeAttempt Whether the offline data should be removed.
-     * @param updated Whether some data was sent to the site.
      * @return Promise resolved on success.
      */
-    protected finishSync(siteId: string, quiz: any, courseId: number, warnings: string[], attemptId?: number, offlineAttempt?: any,
+    protected finishSync(siteId: string, quiz: any, courseId: number, warnings: string[], options?: FinishSyncOptions)
-            onlineAttempt?: any, removeAttempt?: boolean, updated?: boolean): Promise<AddonModQuizSyncResult> {
+            : Promise<AddonModQuizSyncResult> {
+        options = options || {};
 
         // Invalidate the data for the quiz and attempt.
-        return this.quizProvider.invalidateAllQuizData(quiz.id, courseId, attemptId, siteId).catch(() => {
+        return this.quizProvider.invalidateAllQuizData(quiz.id, courseId, options.attemptId, siteId).catch(() => {
             // Ignore errors.
         }).then(() => {
-            if (removeAttempt && attemptId) {
+            if (options.removeAttempt && options.attemptId) {
-                return this.quizOfflineProvider.removeAttemptAndAnswers(attemptId, siteId);
+                const promises = [];
+
+                promises.push(this.quizOfflineProvider.removeAttemptAndAnswers(options.attemptId, siteId));
+
+                if (options.onlineQuestions) {
+                    for (const slot in options.onlineQuestions) {
+                        promises.push(this.questionDelegate.deleteOfflineData(options.onlineQuestions[slot],
+                                AddonModQuizProvider.COMPONENT, quiz.coursemodule, siteId));
+                    }
+                }
+
+                return Promise.all(promises);
             }
         }).then(() => {
-            if (updated) {
+            if (options.updated) {
                 // Data has been sent. Update prefetched data.
                 return this.courseProvider.getModuleBasicInfoByInstance(quiz.id, 'quiz', siteId).then((module) => {
                     return this.prefetchAfterUpdateQuiz(module, quiz, courseId, undefined, siteId);
@@ -109,14 +118,14 @@ export class AddonModQuizSyncProvider extends CoreCourseActivitySyncBaseProvider
             });
         }).then(() => {
             // Check if online attempt was finished because of the sync.
-            if (onlineAttempt && !this.quizProvider.isAttemptFinished(onlineAttempt.state)) {
+            if (options.onlineAttempt && !this.quizProvider.isAttemptFinished(options.onlineAttempt.state)) {
                 // Attempt wasn't finished at start. Check if it's finished now.
                 return this.quizProvider.getUserAttempts(quiz.id, {cmId: quiz.coursemodule, siteId}).then((attempts) => {
                     // Search the attempt.
                     for (const i in attempts) {
                         const attempt = attempts[i];
 
-                        if (attempt.id == onlineAttempt.id) {
+                        if (attempt.id == options.onlineAttempt.id) {
                             return this.quizProvider.isAttemptFinished(attempt.state);
                         }
                     }
@@ -288,16 +297,6 @@ export class AddonModQuizSyncProvider extends CoreCourseActivitySyncBaseProvider
     syncQuiz(quiz: any, askPreflight?: boolean, siteId?: string): Promise<AddonModQuizSyncResult> {
         siteId = siteId || this.sitesProvider.getCurrentSiteId();
 
-        const warnings = [];
-        const courseId = quiz.course;
-        const modOptions = {
-            cmId: quiz.coursemodule,
-            readingStrategy: CoreSitesReadingStrategy.OnlyNetwork,
-            siteId,
-        };
-        let syncPromise;
-        let preflightData;
-
         if (this.isSyncing(quiz.id, siteId)) {
             // There's already a sync ongoing for this quiz, return the promise.
             return this.getOngoingSync(quiz.id, siteId);
@@ -310,115 +309,139 @@ export class AddonModQuizSyncProvider extends CoreCourseActivitySyncBaseProvider
             return Promise.reject(this.translate.instant('core.errorsyncblocked', {$a: this.componentTranslate}));
         }
 
+        return this.addOngoingSync(quiz.id, this.performSyncQuiz(quiz, askPreflight, siteId), siteId);
+    }
+
+    /**
+     * Perform the quiz sync.
+     *
+     * @param quiz Quiz.
+     * @param askPreflight Whether we should ask for preflight data if needed.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved in success.
+     */
+    async performSyncQuiz(quiz: any, askPreflight?: boolean, siteId?: string): Promise<AddonModQuizSyncResult> {
+        siteId = siteId || this.sitesProvider.getCurrentSiteId();
+
+        const warnings = [];
+        const courseId = quiz.course;
+        const modOptions = {
+            cmId: quiz.coursemodule,
+            readingStrategy: CoreSitesReadingStrategy.OnlyNetwork,
+            siteId,
+        };
+
         this.logger.debug('Try to sync quiz ' + quiz.id + ' in site ' + siteId);
 
         // Sync offline logs.
-        syncPromise = this.logHelper.syncIfNeeded(AddonModQuizProvider.COMPONENT, quiz.id, siteId).catch(() => {
+        await CoreUtils.instance.ignoreErrors(this.logHelper.syncIfNeeded(AddonModQuizProvider.COMPONENT, quiz.id, siteId));
-            // Ignore errors.
-        }).then(() => {
-            // Get all the offline attempts for the quiz.
-            return this.quizOfflineProvider.getQuizAttempts(quiz.id, siteId);
-        }).then((attempts) => {
-            // Should return 0 or 1 attempt.
-            if (!attempts.length) {
-                return this.finishSync(siteId, quiz, courseId, warnings);
-            }
 
-            const offlineAttempt = attempts.pop();
+        // Get all the offline attempts for the quiz. It should always be 0 or 1 attempt
+        const offlineAttempts = await this.quizOfflineProvider.getQuizAttempts(quiz.id, siteId);
 
-            // Now get the list of online attempts to make sure this attempt exists and isn't finished.
+        if (!offlineAttempts.length) {
-            return this.quizProvider.getUserAttempts(quiz.id, modOptions).then((attempts) => {
+            // Nothing to sync, finish.
-                const lastAttemptId = attempts.length ? attempts[attempts.length - 1].id : undefined;
+            return this.finishSync(siteId, quiz, courseId, warnings);
-                let onlineAttempt;
+        }
 
-                // Search the attempt we retrieved from offline.
+        if (!this.appProvider.isOnline()) {
-                for (const i in attempts) {
+            // Cannot sync in offline.
-                    const attempt = attempts[i];
+            throw new Error(this.translate.instant('core.cannotconnect'));
+        }
 
-                    if (attempt.id == offlineAttempt.id) {
+        const offlineAttempt = offlineAttempts.pop();
-                        onlineAttempt = attempt;
-                        break;
-                    }
-                }
 
-                if (!onlineAttempt || this.quizProvider.isAttemptFinished(onlineAttempt.state)) {
+        // Now get the list of online attempts to make sure this attempt exists and isn't finished.
-                    // Attempt not found or it's finished in online. Discard it.
+        const onlineAttempts = await this.quizProvider.getUserAttempts(quiz.id, modOptions);
-                    warnings.push(this.translate.instant('addon.mod_quiz.warningattemptfinished'));
 
-                    return this.finishSync(siteId, quiz, courseId, warnings, offlineAttempt.id, offlineAttempt, onlineAttempt,
+        const lastAttemptId = onlineAttempts.length ? onlineAttempts[onlineAttempts.length - 1].id : undefined;
-                            true);
+        const onlineAttempt = onlineAttempts.find((attempt) => {
-                }
+            return attempt.id == offlineAttempt.id;
-
-                // Get the data stored in offline.
-                return this.quizOfflineProvider.getAttemptAnswers(offlineAttempt.id, siteId).then((answersList) => {
-
-                    if (!answersList.length) {
-                        // No answers stored, finish.
-                        return this.finishSync(siteId, quiz, courseId, warnings, lastAttemptId, offlineAttempt, onlineAttempt,
-                                true);
-                    }
-
-                    const answers = this.questionProvider.convertAnswersArrayToObject(answersList),
-                        offlineQuestions = this.quizOfflineProvider.classifyAnswersInQuestions(answers);
-                    let finish;
-
-                    // We're going to need preflightData, get it.
-                    return this.quizProvider.getQuizAccessInformation(quiz.id, modOptions).then((info) => {
-
-                        return this.prefetchHandler.getPreflightData(quiz, info, onlineAttempt, askPreflight,
-                                'core.settings.synchronization', siteId);
-                    }).then((data) => {
-                        preflightData = data;
-
-                        // Now get the online questions data.
-                        const pages = this.quizProvider.getPagesFromLayoutAndQuestions(onlineAttempt.layout, offlineQuestions);
-
-                        return this.quizProvider.getAllQuestionsData(quiz, onlineAttempt, preflightData, {
-                            pages,
-                            readingStrategy: CoreSitesReadingStrategy.OnlyNetwork,
-                            siteId,
-                        });
-                    }).then((onlineQuestions) => {
-
-                        // Validate questions, discarding the offline answers that can't be synchronized.
-                        return this.validateQuestions(onlineAttempt.id, onlineQuestions, offlineQuestions, siteId);
-                    }).then((discardedData) => {
-
-                        // Get the answers to send.
-                        const answers = this.quizOfflineProvider.extractAnswersFromQuestions(offlineQuestions);
-                        finish = offlineAttempt.finished && !discardedData;
-
-                        if (discardedData) {
-                            if (offlineAttempt.finished) {
-                                warnings.push(this.translate.instant('addon.mod_quiz.warningdatadiscardedfromfinished'));
-                            } else {
-                                warnings.push(this.translate.instant('addon.mod_quiz.warningdatadiscarded'));
-                            }
-                        }
-
-                        return this.quizProvider.processAttempt(quiz, onlineAttempt, answers, preflightData, finish, false, false,
-                                siteId);
-                    }).then(() => {
-
-                        // Answers sent, now set the current page if the attempt isn't finished.
-                        if (!finish) {
-                            // Don't pass the quiz instance because we don't want to trigger a Firebase event in this case.
-                            return this.quizProvider.logViewAttempt(onlineAttempt.id, offlineAttempt.currentpage, preflightData,
-                                    false, undefined, siteId).catch(() => {
-                                // Ignore errors.
-                            });
-                        }
-                    }).then(() => {
-
-                        // Data sent. Finish the sync.
-                        return this.finishSync(siteId, quiz, courseId, warnings, lastAttemptId, offlineAttempt, onlineAttempt,
-                                true, true);
-                    });
-                });
-            });
         });
 
-        return this.addOngoingSync(quiz.id, syncPromise, siteId);
+        if (!onlineAttempt || this.quizProvider.isAttemptFinished(onlineAttempt.state)) {
+            // Attempt not found or it's finished in online. Discard it.
+            warnings.push(this.translate.instant('addon.mod_quiz.warningattemptfinished'));
+
+            return this.finishSync(siteId, quiz, courseId, warnings, {
+                attemptId: offlineAttempt.id,
+                offlineAttempt,
+                onlineAttempt,
+                removeAttempt: true,
+            });
+        }
+
+        // Get the data stored in offline.
+        const answersList = await this.quizOfflineProvider.getAttemptAnswers(offlineAttempt.id, siteId);
+
+        if (!answersList.length) {
+            // No answers stored, finish.
+            return this.finishSync(siteId, quiz, courseId, warnings, {
+                attemptId: lastAttemptId,
+                offlineAttempt,
+                onlineAttempt,
+                removeAttempt: true,
+            });
+        }
+
+        const offlineAnswers = this.questionProvider.convertAnswersArrayToObject(answersList);
+        const offlineQuestions = this.quizOfflineProvider.classifyAnswersInQuestions(offlineAnswers);
+
+        // We're going to need preflightData, get it.
+        const info = await this.quizProvider.getQuizAccessInformation(quiz.id, modOptions);
+
+        const preflightData = await this.prefetchHandler.getPreflightData(quiz, info, onlineAttempt, askPreflight,
+                    'core.settings.synchronization', siteId);
+
+        // Now get the online questions data.
+        const onlineQuestions = await this.quizProvider.getAllQuestionsData(quiz, onlineAttempt, preflightData, {
+            pages: this.quizProvider.getPagesFromLayoutAndQuestions(onlineAttempt.layout, offlineQuestions),
+            readingStrategy: CoreSitesReadingStrategy.OnlyNetwork,
+            siteId,
+        });
+
+        // Validate questions, discarding the offline answers that can't be synchronized.
+        const discardedData = await this.validateQuestions(onlineAttempt.id, onlineQuestions, offlineQuestions, siteId);
+
+        // Let questions prepare the data to send.
+        await Promise.all(Object.keys(offlineQuestions).map(async (slot) => {
+            const onlineQuestion = onlineQuestions[slot];
+
+            await this.questionDelegate.prepareSyncData(onlineQuestion, offlineQuestions[slot].answers,
+                    AddonModQuizProvider.COMPONENT, quiz.coursemodule, siteId);
+        }));
+
+        // Get the answers to send.
+        const answers = this.quizOfflineProvider.extractAnswersFromQuestions(offlineQuestions);
+        const finish = offlineAttempt.finished && !discardedData;
+
+        if (discardedData) {
+            if (offlineAttempt.finished) {
+                warnings.push(this.translate.instant('addon.mod_quiz.warningdatadiscardedfromfinished'));
+            } else {
+                warnings.push(this.translate.instant('addon.mod_quiz.warningdatadiscarded'));
+            }
+        }
+
+        // Send the answers.
+        await this.quizProvider.processAttempt(quiz, onlineAttempt, answers, preflightData, finish, false, false, siteId);
+
+        if (!finish) {
+            // Answers sent, now set the current page.
+            // Don't pass the quiz instance because we don't want to trigger a Firebase event in this case.
+            await CoreUtils.instance.ignoreErrors(this.quizProvider.logViewAttempt(onlineAttempt.id, offlineAttempt.currentpage,
+                    preflightData, false, undefined, siteId));
+        }
+
+        // Data sent. Finish the sync.
+        return this.finishSync(siteId, quiz, courseId, warnings, {
+            attemptId: lastAttemptId,
+            offlineAttempt,
+            onlineAttempt,
+            removeAttempt: true,
+            updated: true,
+            onlineQuestions,
+        });
     }
 
     /**
@@ -466,3 +489,15 @@ export class AddonModQuizSyncProvider extends CoreCourseActivitySyncBaseProvider
         });
     }
 }
+
+/**
+ * Options to pass to finish sync.
+ */
+type FinishSyncOptions = {
+    attemptId?: number; // Last attempt ID.
+    offlineAttempt?: any; // Offline attempt synchronized, if any.
+    onlineAttempt?: any; // Online data for the offline attempt.
+    removeAttempt?: boolean; // Whether the offline data should be removed.
+    updated?: boolean; // Whether the offline data should be removed.
+    onlineQuestions?: any; // Online questions indexed by slot.
+};

src/addon/mod/quiz/providers/quiz.ts

@@ -215,6 +215,8 @@ export class AddonModQuizProvider {
             };
 
             return site.read('mod_quiz_get_attempt_data', params, preSets);
+        }).then((result) => {
+            return this.parseQuestions(result);
         });
     }
 
@@ -389,7 +391,9 @@ export class AddonModQuizProvider {
                 ...this.sitesProvider.getReadingStrategyPreSets(options.readingStrategy), // Include reading strategy preSets.
             };
 
-            return site.read('mod_quiz_get_attempt_review', params, preSets);
+            return site.read('mod_quiz_get_attempt_review', params, preSets).then((result) => {
+                return this.parseQuestions(result);
+            });
         });
     }
 
@@ -427,6 +431,8 @@ export class AddonModQuizProvider {
 
             return site.read('mod_quiz_get_attempt_summary', params, preSets).then((response) => {
                 if (response && response.questions) {
+                    response = this.parseQuestions(response);
+
                     if (options.loadLocal) {
                         return this.quizOfflineProvider.loadQuestionsLocalStates(attemptId, response.questions, site.getId());
                     }
@@ -1560,6 +1566,27 @@ export class AddonModQuizProvider {
                 siteId);
     }
 
+    /**
+     * Parse questions of a WS response.
+     *
+     * @param result Result to parse.
+     * @return Parsed result.
+     */
+    parseQuestions(result: any): any {
+        for (let i = 0; i < result.questions.length; i++) {
+            const question = result.questions[i];
+
+            if (!question.settings) {
+                // Site doesn't return settings, stop.
+                break;
+            }
+
+            question.settings = this.textUtils.parseJSON(question.settings, null);
+        }
+
+        return result;
+    }
+
     /**
      * Process an attempt, saving its data.
      *

src/addon/qbehaviour/deferredcbm/providers/handler.ts

@@ -40,13 +40,14 @@ export class AddonQbehaviourDeferredCBMHandler implements CoreQuestionBehaviourH
      * @param component Component the question belongs to.
      * @param attemptId Attempt ID the question belongs to.
      * @param question The question.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return New state (or promise resolved with state).
      */
-    determineNewState(component: string, attemptId: number, question: any, siteId?: string)
+    determineNewState(component: string, attemptId: number, question: any, componentId: string | number, siteId?: string)
             : CoreQuestionState | Promise<CoreQuestionState> {
         // Depends on deferredfeedback.
-        return this.deferredFeedbackHandler.determineNewStateDeferred(component, attemptId, question, siteId,
+        return this.deferredFeedbackHandler.determineNewStateDeferred(component, attemptId, question, componentId, siteId,
             this.isCompleteResponse.bind(this), this.isSameResponse.bind(this));
     }
 
@@ -71,11 +72,13 @@ export class AddonQbehaviourDeferredCBMHandler implements CoreQuestionBehaviourH
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    protected isCompleteResponse(question: any, answers: any): number {
+    protected isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // First check if the question answer is complete.
-        const complete = this.questionDelegate.isCompleteResponse(question, answers);
+        const complete = this.questionDelegate.isCompleteResponse(question, answers, component, componentId);
         if (complete > 0) {
             // Answer is complete, check the user answered CBM too.
             return answers['-certainty'] ? 1 : 0;
@@ -101,12 +104,14 @@ export class AddonQbehaviourDeferredCBMHandler implements CoreQuestionBehaviourH
      * @param prevBasicAnswers Object with the previous basic" answers (without sequencecheck, certainty, ...).
      * @param newAnswers Object with the new question answers.
      * @param newBasicAnswers Object with the previous basic" answers (without sequencecheck, certainty, ...).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    protected isSameResponse(question: any, prevAnswers: any, prevBasicAnswers: any, newAnswers: any, newBasicAnswers: any)
+    protected isSameResponse(question: any, prevAnswers: any, prevBasicAnswers: any, newAnswers: any, newBasicAnswers: any,
-            : boolean {
+            component: string, componentId: string | number): boolean {
         // First check if the question answer is the same.
-        const same = this.questionDelegate.isSameResponse(question, prevBasicAnswers, newBasicAnswers);
+        const same = this.questionDelegate.isSameResponse(question, prevBasicAnswers, newBasicAnswers, component, componentId);
         if (same) {
             // Same response, check the CBM is the same too.
             return prevAnswers['-certainty'] == newAnswers['-certainty'];

src/addon/qbehaviour/deferredfeedback/providers/handler.ts

@@ -23,9 +23,11 @@ import { CoreQuestionProvider, CoreQuestionState } from '@core/question/provider
  *
  * @param question The question.
  * @param answers Object with the question answers (without prefix).
+ * @param component The component the question is related to.
+ * @param componentId Component ID.
  * @return 1 if complete, 0 if not complete, -1 if cannot determine.
  */
-export type isCompleteResponseFunction = (question: any, answers: any) => number;
+export type isCompleteResponseFunction = (question: any, answers: any, component: string, componentId: string | number) => number;
 
 /**
  * Check if two responses are the same.
@@ -35,10 +37,12 @@ export type isCompleteResponseFunction = (question: any, answers: any) => number
  * @param prevBasicAnswers Object with the previous basic" answers (without sequencecheck, certainty, ...).
  * @param newAnswers Object with the new question answers.
  * @param newBasicAnswers Object with the previous basic" answers (without sequencecheck, certainty, ...).
+ * @param component The component the question is related to.
+ * @param componentId Component ID.
  * @return Whether they're the same.
  */
 export type isSameResponseFunction = (question: any, prevAnswers: any, prevBasicAnswers: any, newAnswers: any,
-        newBasicAnswers: any) => boolean;
+        newBasicAnswers: any, component: string, componentId: string | number) => boolean;
 
 /**
  * Handler to support deferred feedback question behaviour.
@@ -58,12 +62,13 @@ export class AddonQbehaviourDeferredFeedbackHandler implements CoreQuestionBehav
      * @param component Component the question belongs to.
      * @param attemptId Attempt ID the question belongs to.
      * @param question The question.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return New state (or promise resolved with state).
      */
-    determineNewState(component: string, attemptId: number, question: any, siteId?: string)
+    determineNewState(component: string, attemptId: number, question: any, componentId: string | number, siteId?: string)
             : CoreQuestionState | Promise<CoreQuestionState> {
-        return this.determineNewStateDeferred(component, attemptId, question, siteId);
+        return this.determineNewStateDeferred(component, attemptId, question, componentId, siteId);
     }
 
     /**
@@ -72,75 +77,82 @@ export class AddonQbehaviourDeferredFeedbackHandler implements CoreQuestionBehav
      * @param component Component the question belongs to.
      * @param attemptId Attempt ID the question belongs to.
      * @param question The question.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @param isCompleteFn Function to override the default isCompleteResponse check.
      * @param isSameFn Function to override the default isSameResponse check.
      * @return Promise resolved with state.
      */
-    determineNewStateDeferred(component: string, attemptId: number, question: any, siteId?: string,
+    async determineNewStateDeferred(component: string, attemptId: number, question: any, componentId: string | number,
-            isCompleteFn?: isCompleteResponseFunction, isSameFn?: isSameResponseFunction): Promise<CoreQuestionState> {
+            siteId?: string, isCompleteFn?: isCompleteResponseFunction, isSameFn?: isSameResponseFunction)
+            : Promise<CoreQuestionState> {
 
         // Check if we have local data for the question.
-        return this.questionProvider.getQuestion(component, attemptId, question.slot, siteId).catch(() => {
+        let dbQuestion;
+        try {
+            dbQuestion = await this.questionProvider.getQuestion(component, attemptId, question.slot, siteId);
+        } catch (error) {
             // No entry found, use the original data.
-            return question;
+            dbQuestion = question;
-        }).then((dbQuestion) => {
+        }
-            const state = this.questionProvider.getState(dbQuestion.state);
 
-            if (state.finished || !state.active) {
+        const state = this.questionProvider.getState(dbQuestion.state);
-                // Question is finished, it cannot change.
+
-                return state;
+        if (state.finished || !state.active) {
+            // Question is finished, it cannot change.
+            return state;
+        }
+
+        const newBasicAnswers = this.questionProvider.getBasicAnswers(question.answers);
+
+        if (dbQuestion.state) {
+            // Question already has a state stored. Check if answer has changed.
+            let prevAnswers = await this.questionProvider.getQuestionAnswers(component, attemptId, question.slot, false, siteId);
+
+            prevAnswers = this.questionProvider.convertAnswersArrayToObject(prevAnswers, true);
+            const prevBasicAnswers = this.questionProvider.getBasicAnswers(prevAnswers);
+
+            // If answers haven't changed the state is the same.
+            if (isSameFn) {
+                if (isSameFn(question, prevAnswers, prevBasicAnswers, question.answers, newBasicAnswers,
+                        component, componentId)) {
+                    return state;
+                }
+            } else {
+                if (this.questionDelegate.isSameResponse(question, prevBasicAnswers, newBasicAnswers, component, componentId)) {
+                    return state;
+                }
             }
+        }
 
-            // We need to check if the answers have changed. Retrieve current stored answers.
+        // Answers have changed. Now check if the response is complete and calculate the new state.
-            return this.questionProvider.getQuestionAnswers(component, attemptId, question.slot, false, siteId)
+        let complete: number;
-                    .then((prevAnswers) => {
+        let newState: string;
 
-                const newBasicAnswers = this.questionProvider.getBasicAnswers(question.answers);
+        if (isCompleteFn) {
+            // Pass all the answers since some behaviours might need the extra data.
+            complete = isCompleteFn(question, question.answers, component, componentId);
+        } else {
+            // Only pass the basic answers since questions should be independent of extra data.
+            complete = this.questionDelegate.isCompleteResponse(question, newBasicAnswers, component, componentId);
+        }
 
-                prevAnswers = this.questionProvider.convertAnswersArrayToObject(prevAnswers, true);
+        if (complete < 0) {
-                const prevBasicAnswers = this.questionProvider.getBasicAnswers(prevAnswers);
+            newState = 'cannotdeterminestatus';
+        } else if (complete > 0) {
+            newState = 'complete';
+        } else {
+            const gradable = this.questionDelegate.isGradableResponse(question, newBasicAnswers, component, componentId);
+            if (gradable < 0) {
+                newState = 'cannotdeterminestatus';
+            } else if (gradable > 0) {
+                newState = 'invalid';
+            } else {
+                newState = 'todo';
+            }
+        }
 
-                // If answers haven't changed the state is the same.
+        return this.questionProvider.getState(newState);
-                if (isSameFn) {
-                    if (isSameFn(question, prevAnswers, prevBasicAnswers, question.answers, newBasicAnswers)) {
-                        return state;
-                    }
-                } else {
-                    if (this.questionDelegate.isSameResponse(question, prevBasicAnswers, newBasicAnswers)) {
-                        return state;
-                    }
-                }
-
-                // Answers have changed. Now check if the response is complete and calculate the new state.
-                let complete: number,
-                    newState: string;
-                if (isCompleteFn) {
-                    // Pass all the answers since some behaviours might need the extra data.
-                    complete = isCompleteFn(question, question.answers);
-                } else {
-                    // Only pass the basic answers since questions should be independent of extra data.
-                    complete = this.questionDelegate.isCompleteResponse(question, newBasicAnswers);
-                }
-
-                if (complete < 0) {
-                    newState = 'cannotdeterminestatus';
-                } else if (complete > 0) {
-                    newState = 'complete';
-                } else {
-                    const gradable = this.questionDelegate.isGradableResponse(question, newBasicAnswers);
-                    if (gradable < 0) {
-                        newState = 'cannotdeterminestatus';
-                    } else if (gradable > 0) {
-                        newState = 'invalid';
-                    } else {
-                        newState = 'todo';
-                    }
-                }
-
-                return this.questionProvider.getState(newState);
-            });
-        });
     }
 
     /**

src/addon/qbehaviour/informationitem/providers/handler.ts

@@ -35,10 +35,11 @@ export class AddonQbehaviourInformationItemHandler implements CoreQuestionBehavi
      * @param component Component the question belongs to.
      * @param attemptId Attempt ID the question belongs to.
      * @param question The question.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return New state (or promise resolved with state).
      */
-    determineNewState(component: string, attemptId: number, question: any, siteId?: string)
+    determineNewState(component: string, attemptId: number, question: any, componentId: string | number, siteId?: string)
             : CoreQuestionState | Promise<CoreQuestionState> {
         if (question.answers['-seen']) {
             return this.questionProvider.getState('complete');

src/addon/qbehaviour/manualgraded/providers/handler.ts

@@ -17,28 +17,7 @@ import { Injectable } from '@angular/core';
 import { CoreQuestionBehaviourHandler } from '@core/question/providers/behaviour-delegate';
 import { CoreQuestionDelegate } from '@core/question/providers/delegate';
 import { CoreQuestionProvider, CoreQuestionState } from '@core/question/providers/question';
-
+import { AddonQbehaviourDeferredFeedbackHandler } from '@addon/qbehaviour/deferredfeedback/providers/handler';
-/**
- * Check if a response is complete.
- *
- * @param question The question.
- * @param answers Object with the question answers (without prefix).
- * @return 1 if complete, 0 if not complete, -1 if cannot determine.
- */
-export type isCompleteResponseFunction = (question: any, answers: any) => number;
-
-/**
- * Check if two responses are the same.
- *
- * @param question Question.
- * @param prevAnswers Object with the previous question answers.
- * @param prevBasicAnswers Object with the previous basic" answers (without sequencecheck, certainty, ...).
- * @param newAnswers Object with the new question answers.
- * @param newBasicAnswers Object with the previous basic" answers (without sequencecheck, certainty, ...).
- * @return Whether they're the same.
- */
-export type isSameResponseFunction = (question: any, prevAnswers: any, prevBasicAnswers: any, newAnswers: any,
-        newBasicAnswers: any) => boolean;
 
 /**
  * Handler to support manual graded question behaviour.
@@ -48,7 +27,9 @@ export class AddonQbehaviourManualGradedHandler implements CoreQuestionBehaviour
     name = 'AddonQbehaviourManualGraded';
     type = 'manualgraded';
 
-    constructor(private questionDelegate: CoreQuestionDelegate, private questionProvider: CoreQuestionProvider) {
+    constructor(protected questionDelegate: CoreQuestionDelegate,
+            protected questionProvider: CoreQuestionProvider,
+            protected deferredFeedbackHandler: AddonQbehaviourDeferredFeedbackHandler) {
         // Nothing to do.
     }
 
@@ -58,82 +39,14 @@ export class AddonQbehaviourManualGradedHandler implements CoreQuestionBehaviour
      * @param component Component the question belongs to.
      * @param attemptId Attempt ID the question belongs to.
      * @param question The question.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return New state (or promise resolved with state).
      */
-    determineNewState(component: string, attemptId: number, question: any, siteId?: string)
+    determineNewState(component: string, attemptId: number, question: any, componentId: string | number, siteId?: string)
             : CoreQuestionState | Promise<CoreQuestionState> {
-        return this.determineNewStateManualGraded(component, attemptId, question, siteId);
+        // Same implementation as the deferred feedback. Use that function instead of replicating it.
-    }
+        return this.deferredFeedbackHandler.determineNewStateDeferred(component, attemptId, question, componentId, siteId);
-
-    /**
-     * Determine a question new state based on its answer(s) for manual graded question behaviour.
-     *
-     * @param component Component the question belongs to.
-     * @param attemptId Attempt ID the question belongs to.
-     * @param question The question.
-     * @param siteId Site ID. If not defined, current site.
-     * @param isCompleteFn Function to override the default isCompleteResponse check.
-     * @param isSameFn Function to override the default isSameResponse check.
-     * @return Promise resolved with state.
-     */
-    determineNewStateManualGraded(component: string, attemptId: number, question: any, siteId?: string,
-            isCompleteFn?: isCompleteResponseFunction, isSameFn?: isSameResponseFunction): Promise<CoreQuestionState> {
-
-        // Check if we have local data for the question.
-        return this.questionProvider.getQuestion(component, attemptId, question.slot, siteId).catch(() => {
-            // No entry found, use the original data.
-            return question;
-        }).then((dbQuestion) => {
-            const state = this.questionProvider.getState(dbQuestion.state);
-
-            if (state.finished || !state.active) {
-                // Question is finished, it cannot change.
-                return state;
-            }
-
-            // We need to check if the answers have changed. Retrieve current stored answers.
-            return this.questionProvider.getQuestionAnswers(component, attemptId, question.slot, false, siteId)
-                    .then((prevAnswers) => {
-
-                const newBasicAnswers = this.questionProvider.getBasicAnswers(question.answers);
-
-                prevAnswers = this.questionProvider.convertAnswersArrayToObject(prevAnswers, true);
-                const prevBasicAnswers = this.questionProvider.getBasicAnswers(prevAnswers);
-
-                // If answers haven't changed the state is the same.
-                if (isSameFn) {
-                    if (isSameFn(question, prevAnswers, prevBasicAnswers, question.answers, newBasicAnswers)) {
-                        return state;
-                    }
-                } else {
-                    if (this.questionDelegate.isSameResponse(question, prevBasicAnswers, newBasicAnswers)) {
-                        return state;
-                    }
-                }
-
-                // Answers have changed. Now check if the response is complete and calculate the new state.
-                let complete: number,
-                    newState: string;
-                if (isCompleteFn) {
-                    // Pass all the answers since some behaviours might need the extra data.
-                    complete = isCompleteFn(question, question.answers);
-                } else {
-                    // Only pass the basic answers since questions should be independent of extra data.
-                    complete = this.questionDelegate.isCompleteResponse(question, newBasicAnswers);
-                }
-
-                if (complete < 0) {
-                    newState = 'cannotdeterminestatus';
-                } else if (complete > 0) {
-                    newState = 'complete';
-                } else {
-                    newState = 'todo';
-                }
-
-                return this.questionProvider.getState(newState);
-            });
-        });
     }
 
     /**

src/addon/qtype/calculated/providers/handler.ts

@@ -24,6 +24,14 @@ import { AddonQtypeCalculatedComponent } from '../component/calculated';
  */
 @Injectable()
 export class AddonQtypeCalculatedHandler implements CoreQuestionHandler {
+    static UNITINPUT = '0';
+    static UNITRADIO = '1';
+    static UNITSELECT = '2';
+    static UNITNONE = '3';
+
+    static UNITGRADED = '1';
+    static UNITOPTIONAL = '0';
+
     name = 'AddonQtypeCalculated';
     type = 'qtype_calculated';
 
@@ -41,23 +49,69 @@ export class AddonQtypeCalculatedHandler implements CoreQuestionHandler {
         return AddonQtypeCalculatedComponent;
     }
 
+    /**
+     * Check if the units are in a separate field for the question.
+     *
+     * @param question Question.
+     * @return Whether units are in a separate field.
+     */
+    hasSeparateUnitField(question: any): boolean {
+        if (!question.settings) {
+            const element = this.domUtils.convertToElement(question.html);
+
+            return !!(element.querySelector('select[name*=unit]') || element.querySelector('input[type="radio"]'));
+        }
+
+        return question.settings.unitdisplay === AddonQtypeCalculatedHandler.UNITRADIO ||
+                question.settings.unitdisplay === AddonQtypeCalculatedHandler.UNITSELECT;
+    }
+
     /**
      * Check if a response is complete.
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
-        if (this.isGradableResponse(question, answers) === 0 || !this.validateUnits(answers['answer'])) {
+        if (!this.isGradableResponse(question, answers, component, componentId)) {
             return 0;
         }
 
-        if (this.requiresUnits(question)) {
+        const parsedAnswer = this.parseAnswer(question, answers['answer']);
-            return this.isValidValue(answers['unit']) ? 1 : 0;
+        if (parsedAnswer.answer === null) {
+            return 0;
         }
 
-        return -1;
+        if (!question.settings) {
+            if (this.hasSeparateUnitField(question)) {
+                return this.isValidValue(answers['unit']) ? 1 : 0;
+            }
+
+            // We cannot know if the answer should contain units or not.
+            return -1;
+        }
+
+        if (question.settings.unitdisplay != AddonQtypeCalculatedHandler.UNITINPUT && parsedAnswer.unit) {
+            // There should be no units or be outside of the input, not valid.
+            return 0;
+        }
+
+        if (this.hasSeparateUnitField(question) && !this.isValidValue(answers['unit'])) {
+            // Unit not supplied as a separate field and it's required.
+            return 0;
+        }
+
+        if (question.settings.unitdisplay == AddonQtypeCalculatedHandler.UNITINPUT &&
+                question.settings.unitgradingtype == AddonQtypeCalculatedHandler.UNITGRADED &&
+                !this.isValidValue(parsedAnswer.unit)) {
+            // Unit not supplied inside the input and it's required.
+            return 0;
+        }
+
+        return 1;
     }
 
     /**
@@ -75,16 +129,12 @@ export class AddonQtypeCalculatedHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
-        let isGradable = this.isValidValue(answers['answer']);
+        return this.isValidValue(answers['answer']) ? 1 : 0;
-        if (isGradable && this.requiresUnits(question)) {
-            // The question requires a unit.
-            isGradable = this.isValidValue(answers['unit']);
-        }
-
-        return isGradable ? 1 : 0;
     }
 
     /**
@@ -93,9 +143,11 @@ export class AddonQtypeCalculatedHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         return this.utils.sameAtKeyMissingIsBlank(prevAnswers, newAnswers, 'answer') &&
             this.utils.sameAtKeyMissingIsBlank(prevAnswers, newAnswers, 'unit');
     }
@@ -111,36 +163,24 @@ export class AddonQtypeCalculatedHandler implements CoreQuestionHandler {
     }
 
     /**
-     * Check if a question requires units in a separate input.
+     * Parse an answer string.
-     *
-     * @param question The question.
-     * @return Whether the question requires units.
-     */
-    requiresUnits(question: any): boolean {
-        const element = this.domUtils.convertToElement(question.html);
-
-        return !!(element.querySelector('select[name*=unit]') || element.querySelector('input[type="radio"]'));
-    }
-
-    /**
-     * Validate a number with units. We don't have the list of valid units and conversions, so we can't perform
-     * a full validation. If this function returns true it means we can't be sure it's valid.
      *
+     * @param question Question.
      * @param answer Answer.
-     * @return False if answer isn't valid, true if we aren't sure if it's valid.
+     * @return 0 if answer isn't valid, 1 if answer is valid, -1 if we aren't sure if it's valid.
      */
-    validateUnits(answer: string): boolean {
+    parseAnswer(question: any, answer: string): {answer: number, unit: string} {
         if (!answer) {
-            return false;
+            return {answer: null, unit: null};
         }
 
-        const regexString = '[+-]?(?:\\d+(?:\\.\\d*)?|\\.\\d+)(?:e[-+]?\\d+)?';
+        let regexString = '[+-]?(?:\\d+(?:\\.\\d*)?|\\.\\d+)(?:e[-+]?\\d+)?';
 
         // Strip spaces (which may be thousands separators) and change other forms of writing e to e.
-        answer = answer.replace(' ', '');
+        answer = answer.replace(/ /g, '');
         answer = answer.replace(/(?:e|E|(?:x|\*|×)10(?:\^|\*\*))([+-]?\d+)/, 'e$1');
 
-        // If a '.' is present or there are multiple ',' (i.e. 2,456,789) assume ',' is a thousands separator and stip it.
+        // If a '.' is present or there are multiple ',' (i.e. 2,456,789) assume ',' is a thousands separator and strip it.
         // Else assume it is a decimal separator, and change it to '.'.
         if (answer.indexOf('.') != -1 || answer.split(',').length - 1 > 1) {
             answer = answer.replace(',', '');
@@ -148,11 +188,31 @@ export class AddonQtypeCalculatedHandler implements CoreQuestionHandler {
             answer = answer.replace(',', '.');
         }
 
-        // We don't know if units should be before or after so we check both.
+        let unitsLeft = false;
-        if (answer.match(new RegExp('^' + regexString)) === null || answer.match(new RegExp(regexString + '$')) === null) {
+        let match = null;
-            return false;
+
+        if (!question.settings) {
+            // We don't know if units should be before or after so we check both.
+            match = answer.match(new RegExp('^' + regexString));
+            if (!match) {
+                unitsLeft = true;
+                match = answer.match(new RegExp(regexString + '$'));
+            }
+        } else {
+            unitsLeft = question.settings.unitsleft == '1';
+            regexString = unitsLeft ? regexString + '$' : '^' + regexString;
+
+            match = answer.match(new RegExp(regexString));
         }
 
-        return true;
+        if (!match) {
+            return {answer: null, unit: null};
+        }
+
+        const numberString = match[0];
+        const unit = unitsLeft ? answer.substr(0, answer.length - match[0].length) : answer.substr(match[0].length);
+
+        // No need to calculate the multiplier.
+        return {answer: Number(numberString), unit: unit};
     }
 }

src/addon/qtype/calculatedmulti/providers/handler.ts

@@ -46,9 +46,11 @@ export class AddonQtypeCalculatedMultiHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // This question type depends on multichoice.
         return this.multichoiceHandler.isCompleteResponseSingle(answers);
     }
@@ -68,9 +70,11 @@ export class AddonQtypeCalculatedMultiHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // This question type depends on multichoice.
         return this.multichoiceHandler.isGradableResponseSingle(answers);
     }
@@ -81,9 +85,11 @@ export class AddonQtypeCalculatedMultiHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         // This question type depends on multichoice.
         return this.multichoiceHandler.isSameResponseSingle(prevAnswers, newAnswers);
     }

src/addon/qtype/calculatedsimple/providers/handler.ts

@@ -46,11 +46,13 @@ export class AddonQtypeCalculatedSimpleHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // This question type depends on calculated.
-        return this.calculatedHandler.isCompleteResponse(question, answers);
+        return this.calculatedHandler.isCompleteResponse(question, answers, component, componentId);
     }
 
     /**
@@ -68,11 +70,13 @@ export class AddonQtypeCalculatedSimpleHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // This question type depends on calculated.
-        return this.calculatedHandler.isGradableResponse(question, answers);
+        return this.calculatedHandler.isGradableResponse(question, answers, component, componentId);
     }
 
     /**
@@ -81,10 +85,12 @@ export class AddonQtypeCalculatedSimpleHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         // This question type depends on calculated.
-        return this.calculatedHandler.isSameResponse(question, prevAnswers, newAnswers);
+        return this.calculatedHandler.isSameResponse(question, prevAnswers, newAnswers, component, componentId);
     }
 }

src/addon/qtype/ddimageortext/providers/handler.ts

@@ -61,9 +61,11 @@ export class AddonQtypeDdImageOrTextHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // An answer is complete if all drop zones have an answer.
         // We should always receive all the drop zones with their value ('' if not answered).
         for (const name in answers) {
@@ -91,9 +93,11 @@ export class AddonQtypeDdImageOrTextHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
         for (const name in answers) {
             const value = answers[name];
             if (value && value !== '0') {
@@ -110,9 +114,11 @@ export class AddonQtypeDdImageOrTextHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         return this.questionProvider.compareAllAnswers(prevAnswers, newAnswers);
     }
 }

src/addon/qtype/ddmarker/providers/handler.ts

@@ -62,9 +62,11 @@ export class AddonQtypeDdMarkerHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // If 1 dragitem is set we assume the answer is complete (like Moodle does).
         for (const name in answers) {
             if (answers[name]) {
@@ -90,10 +92,12 @@ export class AddonQtypeDdMarkerHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
-        return this.isCompleteResponse(question, answers);
+        return this.isCompleteResponse(question, answers, component, componentId);
     }
 
     /**
@@ -102,9 +106,11 @@ export class AddonQtypeDdMarkerHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         return this.questionProvider.compareAllAnswers(prevAnswers, newAnswers);
     }
 

src/addon/qtype/ddwtos/providers/handler.ts

@@ -61,9 +61,11 @@ export class AddonQtypeDdwtosHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         for (const name in answers) {
             const value = answers[name];
             if (!value || value === '0') {
@@ -89,9 +91,11 @@ export class AddonQtypeDdwtosHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
         for (const name in answers) {
             const value = answers[name];
             if (value && value !== '0') {
@@ -108,9 +112,11 @@ export class AddonQtypeDdwtosHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         return this.questionProvider.compareAllAnswers(prevAnswers, newAnswers);
     }
 }

src/addon/qtype/essay/component/addon-qtype-essay.html

@@ -5,9 +5,10 @@
     </ion-item>
 
     <!-- Textarea. -->
-    <ion-item *ngIf="question.textarea && !question.hasDraftFiles">
+    <ion-item *ngIf="question.textarea && (!question.hasDraftFiles || uploadFilesSupported)">
-        <!-- "Format" hidden input -->
+        <!-- "Format" and draftid hidden inputs -->
         <input item-content *ngIf="question.formatInput" type="hidden" [name]="question.formatInput.name" [value]="question.formatInput.value" >
+        <input item-content *ngIf="question.answerDraftIdInput" type="hidden" [name]="question.answerDraftIdInput.name" [value]="question.answerDraftIdInput.value" >
         <!-- Plain text textarea. -->
         <ion-textarea *ngIf="question.isPlainText" class="core-question-textarea" [ngClass]='{"core-monospaced": question.isMonospaced}' placeholder="{{ 'core.question.answer' | translate }}" [attr.name]="question.textarea.name" aria-multiline="true" [ngModel]="question.textarea.text"></ion-textarea>
         <!-- Rich text editor. -->
@@ -15,22 +16,29 @@
     </ion-item>
 
     <!-- Draft files not supported. -->
-    <ng-container *ngIf="question.textarea && question.hasDraftFiles">
+    <ng-container *ngIf="question.textarea && question.hasDraftFiles && !uploadFilesSupported">
         <ion-item text-wrap class="core-danger-item">
-            <p class="core-question-warning">{{ 'core.question.errorinlinefilesnotsupported' | translate }}</p>
+            <p class="core-question-warning">{{ 'core.question.errorinlinefilesnotsupportedinsite' | translate }}</p>
         </ion-item>
         <ion-item text-wrap>
             <p><core-format-text [component]="component" [componentId]="componentId" [text]="question.textarea.text" [contextLevel]="contextLevel" [contextInstanceId]="contextInstanceId" [courseId]="courseId"></core-format-text></p>
         </ion-item>
     </ng-container>
 
-    <!-- Attachments not supported in the app yet. -->
+    <!-- Attachments. -->
-    <ion-item text-wrap *ngIf="question.allowsAttachments" class="core-danger-item">
+    <ng-container *ngIf="question.allowsAttachments">
-        <p class="core-question-warning">{{ 'core.question.errorattachmentsnotsupported' | translate }}</p>
+        <core-attachments *ngIf="uploadFilesSupported" [files]="attachments" [component]="component" [componentId]="componentId" [maxSize]="question.attachmentsMaxBytes" [maxSubmissions]="question.attachmentsMaxFiles" [allowOffline]="offlineEnabled" [acceptedTypes]="question.attachmentsAcceptedTypes"></core-attachments>
-    </ion-item>
+
+        <input item-content *ngIf="uploadFilesSupported" type="hidden" [name]="question.attachmentsDraftIdInput.name" [value]="question.attachmentsDraftIdInput.value" >
+
+        <!-- Attachments not supported in this site. -->
+        <ion-item text-wrap *ngIf="!uploadFilesSupported" class="core-danger-item">
+            <p class="core-question-warning">{{ 'core.question.errorattachmentsnotsupportedinsite' | translate }}</p>
+        </ion-item>
+    </ng-container>
 
     <!-- Answer to the question and attachments (reviewing). -->
-    <ion-item text-wrap *ngIf="!question.textarea && (question.answer || (!question.attachments.length && !question.allowsAttachments))">
+    <ion-item text-wrap *ngIf="!question.textarea && (question.answer || question.answer == '')">
         <p><core-format-text [ngClass]='{"core-monospaced": question.isMonospaced}' [component]="component" [componentId]="componentId" [text]="question.answer" [contextLevel]="contextLevel" [contextInstanceId]="contextInstanceId" [courseId]="courseId"></core-format-text></p>
     </ion-item>
 

src/addon/qtype/essay/component/essay.ts

@@ -14,8 +14,12 @@
 
 import { Component, OnInit, Injector } from '@angular/core';
 import { CoreLoggerProvider } from '@providers/logger';
+import { CoreWSExternalFile } from '@providers/ws';
+import { CoreFileUploader } from '@core/fileuploader/providers/fileuploader';
 import { CoreQuestionBaseComponent } from '@core/question/classes/base-question-component';
+import { CoreQuestion } from '@core/question/providers/question';
 import { FormControl, FormBuilder } from '@angular/forms';
+import { CoreFileSession } from '@providers/file-session';
 
 /**
  * Component to render an essay question.
@@ -28,6 +32,9 @@ export class AddonQtypeEssayComponent extends CoreQuestionBaseComponent implemen
 
     protected formControl: FormControl;
 
+    attachments: CoreWSExternalFile[];
+    uploadFilesSupported: boolean;
+
     constructor(logger: CoreLoggerProvider, injector: Injector, protected fb: FormBuilder) {
         super(logger, 'AddonQtypeEssayComponent', injector);
     }
@@ -36,8 +43,39 @@ export class AddonQtypeEssayComponent extends CoreQuestionBaseComponent implemen
      * Component being initialized.
      */
     ngOnInit(): void {
+        this.uploadFilesSupported = typeof this.question.responsefileareas != 'undefined';
         this.initEssayComponent();
 
         this.formControl = this.fb.control(this.question.textarea && this.question.textarea.text);
+
+        if (this.question.allowsAttachments && this.uploadFilesSupported) {
+            this.loadAttachments();
+        }
+    }
+
+    /**
+     * Load attachments.
+     *
+     * @return Promise resolved when done.
+     */
+    async loadAttachments(): Promise<void> {
+        if (this.offlineEnabled && this.question.localAnswers['attachments_offline']) {
+
+            const attachmentsData = this.textUtils.parseJSON(this.question.localAnswers['attachments_offline'], {});
+            let offlineFiles = [];
+
+            if (attachmentsData.offline) {
+                offlineFiles = await this.questionHelper.getStoredQuestionFiles(this.question, this.component, this.componentId);
+
+                offlineFiles = CoreFileUploader.instance.markOfflineFiles(offlineFiles);
+            }
+
+            this.attachments = (attachmentsData.online || []).concat(offlineFiles);
+        } else {
+            this.attachments = Array.from(this.questionHelper.getResponseFileAreaFiles(this.question, 'attachments'));
+        }
+
+        CoreFileSession.instance.setFiles(this.component,
+                CoreQuestion.instance.getQuestionComponentId(this.question, this.componentId), this.attachments);
     }
 }

src/addon/qtype/essay/providers/handler.ts

@@ -14,11 +14,15 @@
 // limitations under the License.
 
 import { Injectable, Injector } from '@angular/core';
+import { CoreFileSession } from '@providers/file-session';
+import { CoreSites } from '@providers/sites';
 import { CoreTextUtilsProvider } from '@providers/utils/text';
 import { CoreDomUtilsProvider } from '@providers/utils/dom';
 import { CoreUtilsProvider } from '@providers/utils/utils';
+import { CoreFileUploader } from '@core/fileuploader/providers/fileuploader';
 import { CoreQuestionHandler } from '@core/question/providers/delegate';
 import { CoreQuestionHelperProvider } from '@core/question/providers/helper';
+import { CoreQuestion } from '@core/question/providers/question';
 import { AddonQtypeEssayComponent } from '../component/essay';
 
 /**
@@ -32,6 +36,59 @@ export class AddonQtypeEssayHandler implements CoreQuestionHandler {
     constructor(private utils: CoreUtilsProvider, private questionHelper: CoreQuestionHelperProvider,
             private textUtils: CoreTextUtilsProvider, private domUtils: CoreDomUtilsProvider) { }
 
+    /**
+     * Clear temporary data after the data has been saved.
+     *
+     * @param question Question.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     */
+    clearTmpData(question: any, component: string, componentId: string | number): void {
+        const questionComponentId = CoreQuestion.instance.getQuestionComponentId(question, componentId);
+        const files = CoreFileSession.instance.getFiles(component, questionComponentId);
+
+        // Clear the files in session for this question.
+        CoreFileSession.instance.clearFiles(component, questionComponentId);
+
+        // Now delete the local files from the tmp folder.
+        CoreFileUploader.instance.clearTmpFiles(files);
+    }
+
+    /**
+     * Delete any stored data for the question.
+     *
+     * @param question Question.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when done.
+     */
+    deleteOfflineData(question: any, component: string, componentId: string | number, siteId?: string): Promise<void> {
+        return this.questionHelper.deleteStoredQuestionFiles(question, component, componentId, siteId);
+    }
+
+    /**
+     * Check whether the question allows text and/or attachments.
+     *
+     * @param question Question to check.
+     * @return Allowed options.
+     */
+    protected getAllowedOptions(question: any): {text: boolean, attachments: boolean} {
+        if (question.settings) {
+            return {
+                text: question.settings.responseformat != 'noinline',
+                attachments: question.settings.attachments != '0',
+            };
+        } else {
+            const element = this.domUtils.convertToElement(question.html);
+
+            return {
+                text: !!element.querySelector('textarea[name*=_answer]'),
+                attachments: !!element.querySelector('div[id*=filemanager]'),
+            };
+        }
+    }
+
     /**
      * Return the name of the behaviour to use for the question.
      * If the question should use the default behaviour you shouldn't implement this function.
@@ -65,14 +122,15 @@ export class AddonQtypeEssayHandler implements CoreQuestionHandler {
      */
     getPreventSubmitMessage(question: any): string {
         const element = this.domUtils.convertToElement(question.html);
+        const uploadFilesSupported = typeof question.responsefileareas != 'undefined';
 
-        if (element.querySelector('div[id*=filemanager]')) {
+        if (!uploadFilesSupported && element.querySelector('div[id*=filemanager]')) {
             // The question allows attachments. Since the app cannot attach files yet we will prevent submitting the question.
-            return 'core.question.errorattachmentsnotsupported';
+            return 'core.question.errorattachmentsnotsupportedinsite';
         }
 
-        if (this.questionHelper.hasDraftFileUrls(element.innerHTML)) {
+        if (!uploadFilesSupported && this.questionHelper.hasDraftFileUrls(element.innerHTML)) {
-            return 'core.question.errorinlinefilesnotsupported';
+            return 'core.question.errorinlinefilesnotsupportedinsite';
         }
     }
 
@@ -81,20 +139,34 @@ export class AddonQtypeEssayHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
-        const element = this.domUtils.convertToElement(question.html);
 
-        const hasInlineText = answers['answer'] && answers['answer'] !== '',
+        const hasTextAnswer = answers['answer'] && answers['answer'] !== '';
-            allowsAttachments = !!element.querySelector('div[id*=filemanager]');
+        const uploadFilesSupported = typeof question.responsefileareas != 'undefined';
+        const allowedOptions = this.getAllowedOptions(question);
 
-        if (!allowsAttachments) {
+        if (!allowedOptions.attachments) {
-            return hasInlineText ? 1 : 0;
+            return hasTextAnswer ? 1 : 0;
         }
 
-        // We can't know if the attachments are required or if the user added any in web.
+        if (!uploadFilesSupported) {
-        return -1;
+            // We can't know if the attachments are required or if the user added any in web.
+            return -1;
+        }
+
+        const questionComponentId = CoreQuestion.instance.getQuestionComponentId(question, componentId);
+        const attachments = CoreFileSession.instance.getFiles(component, questionComponentId);
+
+        if (!allowedOptions.text) {
+            return attachments && attachments.length >= Number(question.settings.attachmentsrequired) ? 1 : 0;
+        }
+
+        return (hasTextAnswer || question.settings.responserequired == '0') &&
+                (attachments && attachments.length > Number(question.settings.attachmentsrequired)) ? 1 : 0;
     }
 
     /**
@@ -112,10 +184,20 @@ export class AddonQtypeEssayHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
-        return 0;
+        if (typeof question.responsefileareas == 'undefined') {
+            return -1;
+        }
+
+        const questionComponentId = CoreQuestion.instance.getQuestionComponentId(question, componentId);
+        const attachments = CoreFileSession.instance.getFiles(component, questionComponentId);
+
+        // Determine if the given response has online text or attachments.
+        return (answers['answer'] && answers['answer'] !== '') || (attachments && attachments.length > 0) ? 1 : 0;
     }
 
     /**
@@ -124,30 +206,165 @@ export class AddonQtypeEssayHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
-        return this.utils.sameAtKeyMissingIsBlank(prevAnswers, newAnswers, 'answer');
+        const uploadFilesSupported = typeof question.responsefileareas != 'undefined';
+        const allowedOptions = this.getAllowedOptions(question);
+
+        // First check the inline text.
+        const answerIsEqual = allowedOptions.text ? this.utils.sameAtKeyMissingIsBlank(prevAnswers, newAnswers, 'answer') : true;
+
+        if (!allowedOptions.attachments || !uploadFilesSupported || !answerIsEqual) {
+            // No need to check attachments.
+            return answerIsEqual;
+        }
+
+        // Check attachments now.
+        const questionComponentId = CoreQuestion.instance.getQuestionComponentId(question, componentId);
+        const attachments = CoreFileSession.instance.getFiles(component, questionComponentId);
+        const originalAttachments = this.questionHelper.getResponseFileAreaFiles(question, 'attachments');
+
+        return !CoreFileUploader.instance.areFileListDifferent(attachments, originalAttachments);
     }
 
     /**
-     * Prepare and add to answers the data to send to server based in the input. Return promise if async.
+     * Prepare and add to answers the data to send to server based in the input.
      *
      * @param question Question.
      * @param answers The answers retrieved from the form. Prepared answers must be stored in this object.
      * @param offline Whether the data should be saved in offline.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return Return a promise resolved when done if async, void if sync.
      */
-    prepareAnswers(question: any, answers: any, offline: boolean, siteId?: string): void | Promise<any> {
+    async prepareAnswers(question: any, answers: any, offline: boolean, component: string, componentId: string | number,
+            siteId?: string): Promise<void> {
+
         const element = this.domUtils.convertToElement(question.html);
+        const attachmentsInput = <HTMLInputElement> element.querySelector('.attachments input[name*=_attachments]');
 
         // Search the textarea to get its name.
         const textarea = <HTMLTextAreaElement> element.querySelector('textarea[name*=_answer]');
 
         if (textarea && typeof answers[textarea.name] != 'undefined') {
-            // Add some HTML to the text if needed.
+            await this.prepareTextAnswer(question, answers, textarea, siteId);
-            answers[textarea.name] = this.textUtils.formatHtmlLines(answers[textarea.name]);
+        }
+
+        if (attachmentsInput) {
+            await this.prepareAttachments(question, answers, offline, component, componentId, attachmentsInput, siteId);
         }
     }
+
+    /**
+     * Prepare attachments.
+     *
+     * @param question Question.
+     * @param answers The answers retrieved from the form. Prepared answers must be stored in this object.
+     * @param offline Whether the data should be saved in offline.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @param attachmentsInput The HTML input containing the draft ID for attachments.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Return a promise resolved when done if async, void if sync.
+     */
+    async prepareAttachments(question: any, answers: any, offline: boolean, component: string, componentId: string | number,
+            attachmentsInput: HTMLInputElement, siteId?: string): Promise<void> {
+
+        // Treat attachments if any.
+        const questionComponentId = CoreQuestion.instance.getQuestionComponentId(question, componentId);
+        const attachments = CoreFileSession.instance.getFiles(component, questionComponentId);
+        const draftId = Number(attachmentsInput.value);
+
+        if (offline) {
+            // Get the folder where to store the files.
+            const folderPath = CoreQuestion.instance.getQuestionFolder(question.type, component, questionComponentId, siteId);
+
+            const result = await CoreFileUploader.instance.storeFilesToUpload(folderPath, attachments);
+
+            // Store the files in the answers.
+            answers[attachmentsInput.name + '_offline'] = JSON.stringify(result);
+        } else {
+            // Check if any attachment was deleted.
+            const originalAttachments = this.questionHelper.getResponseFileAreaFiles(question, 'attachments');
+            const filesToDelete = CoreFileUploader.instance.getFilesToDelete(originalAttachments, attachments);
+
+            if (filesToDelete.length > 0) {
+                // Delete files.
+                await CoreFileUploader.instance.deleteDraftFiles(draftId, filesToDelete, siteId);
+            }
+
+            await CoreFileUploader.instance.uploadFiles(draftId, attachments, siteId);
+        }
+    }
+
+    /**
+     * Prepare data to send when performing a synchronization.
+     *
+     * @param question Question.
+     * @param answers Answers of the question, without the prefix.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when done.
+     */
+    async prepareSyncData(question: any, answers: {[name: string]: any}, component: string, componentId: string | number,
+            siteId?: string): Promise<void> {
+
+        const element = this.domUtils.convertToElement(question.html);
+        const attachmentsInput = <HTMLInputElement> element.querySelector('.attachments input[name*=_attachments]');
+
+        if (attachmentsInput) {
+            // Update the draft ID, the stored one could no longer be valid.
+            answers.attachments = attachmentsInput.value;
+        }
+
+        if (answers && answers.attachments_offline) {
+            const attachmentsData = this.textUtils.parseJSON(answers.attachments_offline, {});
+
+            // Check if any attachment was deleted.
+            const originalAttachments = this.questionHelper.getResponseFileAreaFiles(question, 'attachments');
+            const filesToDelete = CoreFileUploader.instance.getFilesToDelete(originalAttachments, attachmentsData.online);
+
+            if (filesToDelete.length > 0) {
+                // Delete files.
+                await CoreFileUploader.instance.deleteDraftFiles(answers.attachments, filesToDelete, siteId);
+            }
+
+            if (attachmentsData.offline) {
+                // Upload the offline files.
+                const offlineFiles = await this.questionHelper.getStoredQuestionFiles(question, component, componentId, siteId);
+
+                await CoreFileUploader.instance.uploadFiles(answers.attachments, attachmentsData.online.concat(offlineFiles),
+                        siteId);
+            }
+
+            delete answers.attachments_offline;
+        }
+    }
+
+    /**
+     * Prepare the text answer.
+     *
+     * @param question Question.
+     * @param answers The answers retrieved from the form. Prepared answers must be stored in this object.
+     * @param textarea The textarea HTML element of the question.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when done.
+     */
+    async prepareTextAnswer(question: any, answers: any, textarea: HTMLTextAreaElement, siteId?: string): Promise<void> {
+        if (this.questionHelper.hasDraftFileUrls(question.html) && question.responsefileareas) {
+            // Restore draftfile URLs.
+            const site = await CoreSites.instance.getSite(siteId);
+
+            answers[textarea.name] = this.textUtils.restoreDraftfileUrls(site.getURL(), answers[textarea.name],
+                    question.html, this.questionHelper.getResponseFileAreaFiles(question, 'answer'));
+        }
+
+        // Add some HTML to the text if needed.
+        answers[textarea.name] = this.textUtils.formatHtmlLines(answers[textarea.name]);
+    }
 }

src/addon/qtype/gapselect/providers/handler.ts

@@ -61,9 +61,11 @@ export class AddonQtypeGapSelectHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // We should always get a value for each select so we can assume we receive all the possible answers.
         for (const name in answers) {
             const value = answers[name];
@@ -90,9 +92,11 @@ export class AddonQtypeGapSelectHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // We should always get a value for each select so we can assume we receive all the possible answers.
         for (const name in answers) {
             const value = answers[name];
@@ -110,9 +114,11 @@ export class AddonQtypeGapSelectHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         return this.questionProvider.compareAllAnswers(prevAnswers, newAnswers);
     }
 }

src/addon/qtype/match/providers/handler.ts

@@ -61,9 +61,11 @@ export class AddonQtypeMatchHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // We should always get a value for each select so we can assume we receive all the possible answers.
         for (const name in answers) {
             const value = answers[name];
@@ -90,9 +92,11 @@ export class AddonQtypeMatchHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // We should always get a value for each select so we can assume we receive all the possible answers.
         for (const name in answers) {
             const value = answers[name];
@@ -110,9 +114,11 @@ export class AddonQtypeMatchHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         return this.questionProvider.compareAllAnswers(prevAnswers, newAnswers);
     }
 }

src/addon/qtype/multianswer/providers/handler.ts

@@ -62,9 +62,11 @@ export class AddonQtypeMultiAnswerHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // Get all the inputs in the question to check if they've all been answered.
         const names = this.questionProvider.getBasicAnswers(this.questionHelper.getAllInputNamesFromHtml(question.html));
         for (const name in names) {
@@ -92,9 +94,11 @@ export class AddonQtypeMultiAnswerHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // We should always get a value for each select so we can assume we receive all the possible answers.
         for (const name in answers) {
             const value = answers[name];
@@ -112,9 +116,11 @@ export class AddonQtypeMultiAnswerHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         return this.questionProvider.compareAllAnswers(prevAnswers, newAnswers);
     }
 

src/addon/qtype/multichoice/providers/handler.ts

@@ -45,9 +45,11 @@ export class AddonQtypeMultichoiceHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         let isSingle = true,
             isMultiComplete = false;
 
@@ -95,10 +97,12 @@ export class AddonQtypeMultichoiceHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
-        return this.isCompleteResponse(question, answers);
+        return this.isCompleteResponse(question, answers, component, componentId);
     }
 
     /**
@@ -118,9 +122,11 @@ export class AddonQtypeMultichoiceHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         let isSingle = true,
             isMultiSame = true;
 
@@ -158,10 +164,13 @@ export class AddonQtypeMultichoiceHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param answers The answers retrieved from the form. Prepared answers must be stored in this object.
      * @param offline Whether the data should be saved in offline.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return Return a promise resolved when done if async, void if sync.
      */
-    prepareAnswers(question: any, answers: any, offline: boolean, siteId?: string): void | Promise<any> {
+    prepareAnswers(question: any, answers: any, offline: boolean, component: string, componentId: string | number, siteId?: string)
+            : void | Promise<any> {
         if (question && !question.multi && typeof answers[question.optionsName] != 'undefined' && !answers[question.optionsName]) {
             /* It's a single choice and the user hasn't answered. Delete the answer because
                sending an empty string (default value) will mark the first option as selected. */

src/addon/qtype/randomsamatch/providers/handler.ts

@@ -46,11 +46,13 @@ export class AddonQtypeRandomSaMatchHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // This question behaves like a match question.
-        return this.matchHandler.isCompleteResponse(question, answers);
+        return this.matchHandler.isCompleteResponse(question, answers, component, componentId);
     }
 
     /**
@@ -68,11 +70,13 @@ export class AddonQtypeRandomSaMatchHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
         // This question behaves like a match question.
-        return this.matchHandler.isGradableResponse(question, answers);
+        return this.matchHandler.isGradableResponse(question, answers, component, componentId);
     }
 
     /**
@@ -81,10 +85,12 @@ export class AddonQtypeRandomSaMatchHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         // This question behaves like a match question.
-        return this.matchHandler.isSameResponse(question, prevAnswers, newAnswers);
+        return this.matchHandler.isSameResponse(question, prevAnswers, newAnswers, component, componentId);
     }
 }

src/addon/qtype/shortanswer/providers/handler.ts

@@ -45,9 +45,11 @@ export class AddonQtypeShortAnswerHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         return (answers['answer'] || answers['answer'] === 0) ? 1 : 0;
     }
 
@@ -66,10 +68,12 @@ export class AddonQtypeShortAnswerHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
-        return this.isCompleteResponse(question, answers);
+        return this.isCompleteResponse(question, answers, null, null);
     }
 
     /**
@@ -78,9 +82,11 @@ export class AddonQtypeShortAnswerHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         return this.utils.sameAtKeyMissingIsBlank(prevAnswers, newAnswers, 'answer');
     }
 }

src/addon/qtype/truefalse/providers/handler.ts

@@ -46,9 +46,11 @@ export class AddonQtypeTrueFalseHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         return answers['answer'] ? 1 : 0;
     }
 
@@ -67,10 +69,12 @@ export class AddonQtypeTrueFalseHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
-        return this.isCompleteResponse(question, answers);
+        return this.isCompleteResponse(question, answers, null, null);
     }
 
     /**
@@ -79,9 +83,11 @@ export class AddonQtypeTrueFalseHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         return this.utils.sameAtKeyMissingIsBlank(prevAnswers, newAnswers, 'answer');
     }
 
@@ -91,10 +97,13 @@ export class AddonQtypeTrueFalseHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param answers The answers retrieved from the form. Prepared answers must be stored in this object.
      * @param offline Whether the data should be saved in offline.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return Return a promise resolved when done if async, void if sync.
      */
-    prepareAnswers(question: any, answers: any, offline: boolean, siteId?: string): void | Promise<any> {
+    prepareAnswers(question: any, answers: any, offline: boolean, component: string, componentId: string | number, siteId?: string)
+            : void | Promise<any> {
         if (question && typeof answers[question.optionsName] != 'undefined' && !answers[question.optionsName]) {
             // The user hasn't answered. Delete the answer to prevent marking one of the answers automatically.
             delete answers[question.optionsName];

src/assets/lang/en.json

@@ -1861,6 +1861,7 @@
     "core.mainmenu.help": "Help",
     "core.mainmenu.logout": "Log out",
     "core.mainmenu.website": "Website",
+    "core.maxfilesize": "Maximum size for new files: {{$a}}",
     "core.maxsizeandattachments": "Maximum file size: {{$a.size}}, maximum number of files: {{$a.attachments}}",
     "core.min": "min",
     "core.mins": "mins",
@@ -1944,8 +1945,8 @@
     "core.question.certainty": "Certainty",
     "core.question.complete": "Complete",
     "core.question.correct": "Correct",
-    "core.question.errorattachmentsnotsupported": "The application doesn't support attaching files to answers yet.",
+    "core.question.errorattachmentsnotsupportedinsite": "Your site doesn't support attaching files to answers yet.",
-    "core.question.errorinlinefilesnotsupported": "The application doesn't support editing inline files yet.",
+    "core.question.errorembeddedfilesnotsupportedinsite": "Your site doesn't support editing embedded files yet.",
     "core.question.errorquestionnotsupported": "This question type is not supported by the app: {{$a}}.",
     "core.question.feedback": "Feedback",
     "core.question.howtodraganddrop": "Tap to select then tap to drop.",

src/classes/site.ts

@@ -221,13 +221,16 @@ export class CoreSite {
 
     // Versions of Moodle releases.
     protected MOODLE_RELEASES = {
-        3.1: 2016052300,
+        '3.1': 2016052300,
-        3.2: 2016120500,
+        '3.2': 2016120500,
-        3.3: 2017051503,
+        '3.3': 2017051503,
-        3.4: 2017111300,
+        '3.4': 2017111300,
-        3.5: 2018051700,
+        '3.5': 2018051700,
-        3.6: 2018120300,
+        '3.6': 2018120300,
-        3.7: 2019052000
+        '3.7': 2019052000,
+        '3.8': 2019111800,
+        '3.9': 2020061500,
+        '3.10': 2020092400, // @todo: Replace with the right value once 3.10 is released.
     };
     static MINIMUM_MOODLE_VERSION = '3.1';
 

src/components/attachments/attachments.ts

@@ -39,8 +39,8 @@ import { CoreFileUploaderHelperProvider } from '@core/fileuploader/providers/hel
 })
 export class CoreAttachmentsComponent implements OnInit {
     @Input() files: any[]; // List of attachments. New attachments will be added to this array.
-    @Input() maxSize: number; // Max size for attachments. If not defined, 0 or -1, unknown size.
+    @Input() maxSize: number; // Max size for attachments. -1 means unlimited, not defined or 0 means unknown limit.
-    @Input() maxSubmissions: number; // Max number of attachments. If -1 or not defined, unknown limit.
+    @Input() maxSubmissions: number; // Max number of attachments. -1 means unlimited, not defined means unknown limit.
     @Input() component: string; // Component the downloaded files will be linked to.
     @Input() componentId: string | number; // Component ID.
     @Input() allowOffline: boolean | string; // Whether to allow selecting files in offline.
@@ -61,17 +61,18 @@ export class CoreAttachmentsComponent implements OnInit {
      * Component being initialized.
      */
     ngOnInit(): void {
-        this.maxSize = Number(this.maxSize); // Make sure it's defined and it's a number.
+        this.maxSize = Number(this.maxSize) || 0; // Make sure it's defined and it's a number.
-        this.maxSize = !isNaN(this.maxSize) && this.maxSize > 0 ? this.maxSize : -1;
 
-        if (this.maxSize == -1) {
+        if (this.maxSize === 0) {
             this.maxSizeReadable = this.translate.instant('core.unknown');
-        } else {
+        } else if (this.maxSize > 0) {
             this.maxSizeReadable = this.textUtils.bytesToSize(this.maxSize, 2);
+        } else {
+            this.maxSizeReadable = this.translate.instant('core.unlimited');
         }
 
         if (typeof this.maxSubmissions == 'undefined' || this.maxSubmissions < 0) {
-            this.maxSubmissionsReadable = this.translate.instant('core.unknown');
+            this.maxSubmissionsReadable = this.maxSubmissions < 0 ? undefined : this.translate.instant('core.unknown');
             this.unlimitedFiles = true;
         } else {
             this.maxSubmissionsReadable = String(this.maxSubmissions);

src/components/attachments/core-attachments.html

@@ -1,5 +1,6 @@
 <ion-item text-wrap>
-    {{ 'core.maxsizeandattachments' | translate:{$a: {size: maxSizeReadable, attachments: maxSubmissionsReadable} } }}
+    <span *ngIf="maxSubmissionsReadable">{{ 'core.maxsizeandattachments' | translate:{$a: {size: maxSizeReadable, attachments: maxSubmissionsReadable} } }}</span>
+    <span *ngIf="!maxSubmissionsReadable">{{ 'core.maxfilesize' | translate:{$a: maxSizeReadable} }}</span>
     <span [core-mark-required]="required" class="core-mark-required"></span>
 </ion-item>
 <ion-item text-wrap *ngIf="fileTypes && fileTypes.mimetypes && fileTypes.mimetypes.length">

src/core/editor/components/rich-text-editor/rich-text-editor.scss

@@ -56,6 +56,7 @@ ion-app.app-root core-rich-text-editor {
         img {
             @include padding(null, null, null, 2px);
             max-width: 95%;
+            width: auto;
         }
         &:empty:before {
             content: attr(data-placeholder-text);

src/core/fileuploader/providers/fileuploader.ts

@@ -15,6 +15,7 @@
 import { Injectable } from '@angular/core';
 import { ModalController } from 'ionic-angular';
 import { Camera, CameraOptions } from '@ionic-native/camera';
+import { FileEntry } from '@ionic-native/file';
 import { MediaCapture, MediaFile, CaptureError, CaptureAudioOptions, CaptureVideoOptions } from '@ionic-native/media-capture';
 import { TranslateService } from '@ngx-translate/core';
 import { CoreFileProvider } from '@providers/file';
@@ -25,9 +26,11 @@ import { CoreMimetypeUtilsProvider } from '@providers/utils/mimetype';
 import { CoreTextUtilsProvider } from '@providers/utils/text';
 import { CoreTimeUtilsProvider } from '@providers/utils/time';
 import { CoreUtilsProvider } from '@providers/utils/utils';
-import { CoreWSFileUploadOptions } from '@providers/ws';
+import { CoreWSFileUploadOptions, CoreWSExternalFile } from '@providers/ws';
 import { Subject } from 'rxjs';
 import { CoreApp } from '@providers/app';
+import { CoreSite } from '@classes/site';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * File upload options.
@@ -96,7 +99,7 @@ export class CoreFileUploaderProvider {
         // Currently we are going to compare the order of the files as well.
         // This function can be improved comparing more fields or not comparing the order.
         for (let i = 0; i < a.length; i++) {
-            if ((a[i].name || a[i].filename) != (b[i].name || b[i].filename)) {
+            if (a[i].name != b[i].name || a[i].filename != b[i].filename) {
                 return true;
             }
         }
@@ -104,6 +107,36 @@ export class CoreFileUploaderProvider {
         return false;
     }
 
+    /**
+     * Check if a certain site allows deleting draft files.
+     *
+     * @param siteId Site Id. If not defined, use current site.
+     * @return Promise resolved with true if can delete.
+     * @since 3.10
+     */
+    async canDeleteDraftFiles(siteId?: string): Promise<boolean> {
+        try {
+            const site = await this.sitesProvider.getSite(siteId);
+
+            return this.canDeleteDraftFilesInSite(site);
+        } catch (error) {
+            return false;
+        }
+    }
+
+    /**
+     * Check if a certain site allows deleting draft files.
+     *
+     * @param site Site. If not defined, use current site.
+     * @return Whether draft files can be deleted.
+     * @since 3.10
+     */
+    canDeleteDraftFilesInSite(site?: CoreSite): boolean {
+        site = site || this.sitesProvider.getCurrentSite();
+
+        return site.wsAvailable('core_files_delete_draft_files');
+    }
+
     /**
      * Start the audio recorder application and return information about captured audio clip files.
      *
@@ -173,6 +206,25 @@ export class CoreFileUploaderProvider {
         });
     }
 
+    /**
+     * Delete draft files.
+     *
+     * @param draftId Draft ID.
+     * @param files Files to delete.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when done.
+     */
+    async deleteDraftFiles(draftId: number, files: {filepath: string, filename: string}[], siteId?: string): Promise<void> {
+        const site = await this.sitesProvider.getSite(siteId);
+
+        const params = {
+            draftitemid: draftId,
+            files: files,
+        };
+
+        return site.write('core_files_delete_draft_files', params);
+    }
+
     /**
      * Get the upload options for a file taken with the Camera Cordova plugin.
      *
@@ -215,6 +267,35 @@ export class CoreFileUploaderProvider {
         return options;
     }
 
+    /**
+     * Given a list of original files and a list of current files, return the list of files to delete.
+     *
+     * @param originalFiles Original files.
+     * @param currentFiles Current files.
+     * @return List of files to delete.
+     */
+    getFilesToDelete(originalFiles: CoreWSExternalFile[], currentFiles: (CoreWSExternalFile | FileEntry)[])
+            : {filepath: string, filename: string}[] {
+
+        const filesToDelete: {filepath: string, filename: string}[] = [];
+        currentFiles = currentFiles || [];
+
+        originalFiles.forEach((file) => {
+            const stillInList = currentFiles.some((currentFile) => {
+                return (<CoreWSExternalFile> currentFile).fileurl == file.fileurl;
+            });
+
+            if (!stillInList) {
+                filesToDelete.push({
+                    filepath: file.filepath,
+                    filename: file.filename,
+                });
+            }
+        });
+
+        return filesToDelete;
+    }
+
     /**
      * Get the upload options for a file of any type.
      *
@@ -534,6 +615,47 @@ export class CoreFileUploaderProvider {
         });
     }
 
+    /**
+     * Given a list of files (either online files or local files), upload the local files to the draft area.
+     * Local files are not deleted from the device after upload.
+     *
+     * @param itemId Draft ID.
+     * @param files List of files.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved with the itemId.
+     */
+    async uploadFiles(itemId: number, files: (CoreWSExternalFile | FileEntry)[], siteId?: string): Promise<void> {
+        siteId = siteId || this.sitesProvider.getCurrentSiteId();
+
+        if (!files || !files.length) {
+            return;
+        }
+
+        // Index the online files by name.
+        const usedNames: {[name: string]: (CoreWSExternalFile | FileEntry)} = {};
+        const filesToUpload: FileEntry[] = [];
+        files.forEach((file) => {
+            const isOnlineFile = (<CoreWSExternalFile> file).filename && !(<FileEntry> file).name;
+
+            if (isOnlineFile) {
+                usedNames[(<CoreWSExternalFile> file).filename.toLowerCase()] = file;
+            } else {
+                filesToUpload.push(<FileEntry> file);
+            }
+        });
+
+        await Promise.all(filesToUpload.map(async (file) => {
+            // Make sure the file name is unique in the area.
+            const name = this.fileProvider.calculateUniqueName(usedNames, file.name);
+            usedNames[name] = file;
+
+            // Now upload the file.
+            const options = this.getFileUploadOptions(file.toURL(), name, undefined, false, 'draft', itemId);
+
+            await this.uploadFile(file.toURL(), options, undefined, siteId);
+        }));
+    }
+
     /**
      * Upload a file to a draft area and return the draft ID.
      *
@@ -615,3 +737,5 @@ export class CoreFileUploaderProvider {
         });
     }
 }
+
+export class CoreFileUploader extends makeSingleton(CoreFileUploaderProvider) {}

src/core/grades/providers/helper.ts

@@ -407,7 +407,7 @@ export class CoreGradesHelperProvider {
                     if (matches && matches.length) {
                         const hrefParams = this.urlUtils.extractUrlParams(matches[1]);
 
-                        return hrefParams && hrefParams.id == moduleId;
+                        return hrefParams && Number(hrefParams.id) == moduleId;
                     }
                 }
 

src/core/login/providers/helper.ts

@@ -1152,7 +1152,7 @@ export class CoreLoginHelperProvider {
                     const providerToUse = identityProviders.find((provider) => {
                         const params = this.urlUtils.extractUrlParams(provider.url);
 
-                        return params.id == currentSite.getOAuthId();
+                        return Number(params.id) == currentSite.getOAuthId();
                     });
 
                     if (providerToUse) {

src/core/question/classes/base-behaviour-handler.ts

@@ -34,10 +34,11 @@ export class CoreQuestionBehaviourBaseHandler implements CoreQuestionBehaviourHa
      * @param component Component the question belongs to.
      * @param attemptId Attempt ID the question belongs to.
      * @param question The question.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return New state (or promise resolved with state).
      */
-    determineNewState(component: string, attemptId: number, question: any, siteId?: string)
+    determineNewState(component: string, attemptId: number, question: any, componentId: string | number, siteId?: string)
             : CoreQuestionState | Promise<CoreQuestionState> {
         // Return the current state.
         return this.questionProvider.getState(question.state);

src/core/question/classes/base-question-component.ts

@@ -14,8 +14,10 @@
 
 import { Input, Output, EventEmitter, Injector, ElementRef } from '@angular/core';
 import { CoreLoggerProvider } from '@providers/logger';
+import { CoreSites } from '@providers/sites';
 import { CoreDomUtilsProvider } from '@providers/utils/dom';
 import { CoreTextUtilsProvider } from '@providers/utils/text';
+import { CoreUrlUtils } from '@providers/utils/url';
 import { CoreQuestionHelperProvider } from '@core/question/providers/helper';
 
 /**
@@ -105,9 +107,13 @@ export class CoreQuestionBaseComponent {
                 this.question.select = selectModel;
 
                 // Check which one should be displayed first: the select or the input.
-                const input = questionEl.querySelector('input[type="text"][name*=answer]');
+                if (this.question.settings) {
-                this.question.selectFirst =
+                    this.question.selectFirst = this.question.settings.unitsleft == '1';
-                        questionEl.innerHTML.indexOf(input.outerHTML) > questionEl.innerHTML.indexOf(select.outerHTML);
+                } else {
+                    const input = questionEl.querySelector('input[type="text"][name*=answer]');
+                    this.question.selectFirst =
+                            questionEl.innerHTML.indexOf(input.outerHTML) > questionEl.innerHTML.indexOf(select.outerHTML);
+                }
 
                 return questionEl;
             }
@@ -159,9 +165,15 @@ export class CoreQuestionBaseComponent {
             }
 
             // Check which one should be displayed first: the options or the input.
-            const input = questionEl.querySelector('input[type="text"][name*=answer]');
+            if (this.question.settings) {
-            this.question.optionsFirst =
+                this.question.optionsFirst = this.question.settings.unitsleft == '1';
-                    questionEl.innerHTML.indexOf(input.outerHTML) > questionEl.innerHTML.indexOf(radios[0].outerHTML);
+            } else {
+                const input = questionEl.querySelector('input[type="text"][name*=answer]');
+                this.question.optionsFirst =
+                        questionEl.innerHTML.indexOf(input.outerHTML) > questionEl.innerHTML.indexOf(radios[0].outerHTML);
+            }
+
+            return questionEl;
         }
     }
 
@@ -201,27 +213,46 @@ export class CoreQuestionBaseComponent {
         const questionEl = this.initComponent();
 
         if (questionEl) {
-            // First search the textarea.
             const textarea = <HTMLTextAreaElement> questionEl.querySelector('textarea[name*=_answer]');
-            this.question.allowsAttachments = !!questionEl.querySelector('div[id*=filemanager]');
+            const answerDraftIdInput = <HTMLInputElement> questionEl.querySelector('input[name*="_answer:itemid"]');
-            this.question.isMonospaced = !!questionEl.querySelector('.qtype_essay_monospaced');
-            this.question.isPlainText = this.question.isMonospaced || !!questionEl.querySelector('.qtype_essay_plain');
-            this.question.hasDraftFiles = this.questionHelper.hasDraftFileUrls(questionEl.innerHTML);
 
-            if (!textarea) {
+            if (this.question.settings) {
-                // Textarea not found, we might be in review. Search the answer and the attachments.
+                this.question.allowsAttachments = this.question.settings.attachments != '0';
+                this.question.allowsAnswerFiles = this.question.settings.responseformat == 'editorfilepicker';
+                this.question.isMonospaced = this.question.settings.responseformat == 'monospaced';
+                this.question.isPlainText = this.question.isMonospaced || this.question.settings.responseformat == 'plain';
+            } else {
+                this.question.allowsAttachments = !!questionEl.querySelector('div[id*=filemanager]');
+                this.question.allowsAnswerFiles = !!answerDraftIdInput;
+                this.question.isMonospaced = !!questionEl.querySelector('.qtype_essay_monospaced');
+                this.question.isPlainText = this.question.isMonospaced || !!questionEl.querySelector('.qtype_essay_plain');
+            }
+
+            this.question.hasDraftFiles = this.question.allowsAnswerFiles &&
+                    this.questionHelper.hasDraftFileUrls(questionEl.innerHTML);
+
+            if (!textarea && !this.question.allowsAttachments) {
+                // Textarea and filemanager not found, we might be in review. Search the answer and the attachments.
                 this.question.answer = this.domUtils.getContentsOfElement(questionEl, '.qtype_essay_response');
                 this.question.attachments = this.questionHelper.getQuestionAttachmentsFromHtml(
                         this.domUtils.getContentsOfElement(questionEl, '.attachments'));
-            } else {
+
-                // Textarea found.
+                return questionEl;
-                const input = <HTMLInputElement> questionEl.querySelector('input[type="hidden"][name*=answerformat]'),
+            }
-                    content = textarea.innerHTML;
+
+            if (textarea) {
+                const input = <HTMLInputElement> questionEl.querySelector('input[type="hidden"][name*=answerformat]');
+                let content = this.textUtils.decodeHTML(textarea.innerHTML || '');
+
+                if (this.question.hasDraftFiles && this.question.responsefileareas) {
+                    content = this.textUtils.replaceDraftfileUrls(CoreSites.instance.getCurrentSite().getURL(), content,
+                            this.questionHelper.getResponseFileAreaFiles(this.question, 'answer')).text;
+                }
 
                 this.question.textarea = {
                     id: textarea.id,
                     name: textarea.name,
-                    text: content ? this.textUtils.decodeHTML(content) : ''
+                    text: content,
                 };
 
                 if (input) {
@@ -231,6 +262,43 @@ export class CoreQuestionBaseComponent {
                     };
                 }
             }
+
+            if (answerDraftIdInput) {
+                this.question.answerDraftIdInput = {
+                    name: answerDraftIdInput.name,
+                    value: Number(answerDraftIdInput.value),
+                };
+            }
+
+            if (this.question.allowsAttachments) {
+                const attachmentsInput = <HTMLInputElement> questionEl.querySelector('.attachments input[name*=_attachments]');
+                const objectElement = <HTMLObjectElement> questionEl.querySelector('.attachments object');
+                const fileManagerUrl = objectElement && objectElement.data;
+
+                if (attachmentsInput) {
+                    this.question.attachmentsDraftIdInput = {
+                        name: attachmentsInput.name,
+                        value: Number(attachmentsInput.value),
+                    };
+                }
+
+                if (this.question.settings) {
+                    this.question.attachmentsMaxFiles = Number(this.question.settings.attachments);
+                    this.question.attachmentsAcceptedTypes = this.question.settings.filetypeslist &&
+                        this.question.settings.filetypeslist.join(',');
+                }
+
+                if (fileManagerUrl) {
+                    const params = CoreUrlUtils.instance.extractUrlParams(fileManagerUrl);
+                    const maxBytes = Number(params.maxbytes);
+                    const areaMaxBytes = Number(params.areamaxbytes);
+
+                    this.question.attachmentsMaxBytes = maxBytes === -1 || areaMaxBytes === -1 ?
+                            Math.max(maxBytes, areaMaxBytes) : Math.min(maxBytes, areaMaxBytes);
+                }
+            }
+
+            return questionEl;
         }
     }
 
@@ -270,6 +338,8 @@ export class CoreQuestionBaseComponent {
 
         // Set the question text.
         this.question.text = content.innerHTML;
+
+        return element;
     }
 
     /**

src/core/question/classes/base-question-handler.ts

@@ -79,9 +79,11 @@ export class CoreQuestionBaseHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         return -1;
     }
 
@@ -91,9 +93,11 @@ export class CoreQuestionBaseHandler implements CoreQuestionHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
         return -1;
     }
 
@@ -103,9 +107,11 @@ export class CoreQuestionBaseHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param prevAnswers Object with the previous question answers.
      * @param newAnswers Object with the new question answers.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         return false;
     }
 
@@ -115,10 +121,13 @@ export class CoreQuestionBaseHandler implements CoreQuestionHandler {
      * @param question Question.
      * @param answers The answers retrieved from the form. Prepared answers must be stored in this object.
      * @param offline Whether the data should be saved in offline.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return Return a promise resolved when done if async, void if sync.
      */
-    prepareAnswers(question: any, answers: any, offline: boolean, siteId?: string): void | Promise<any> {
+    prepareAnswers(question: any, answers: any, offline: boolean, component: string, componentId: string | number, siteId?: string)
+            : void | Promise<any> {
         // Nothing to do.
     }
 

src/core/question/lang/en.json

@@ -5,8 +5,8 @@
     "certainty": "Certainty",
     "complete": "Complete",
     "correct": "Correct",
-    "errorattachmentsnotsupported": "The application doesn't support attaching files to answers yet.",
+    "errorattachmentsnotsupportedinsite": "Your site doesn't support attaching files to answers yet.",
-    "errorinlinefilesnotsupported": "The application doesn't support editing inline files yet.",
+    "errorembeddedfilesnotsupportedinsite": "Your site doesn't support editing embedded files yet.",
     "errorquestionnotsupported": "This question type is not supported by the app: {{$a}}.",
     "feedback": "Feedback",
     "howtodraganddrop": "Tap to select then tap to drop.",

src/core/question/providers/behaviour-delegate.ts

@@ -36,10 +36,11 @@ export interface CoreQuestionBehaviourHandler extends CoreDelegateHandler {
      * @param component Component the question belongs to.
      * @param attemptId Attempt ID the question belongs to.
      * @param question The question.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return State (or promise resolved with state).
      */
-    determineNewState?(component: string, attemptId: number, question: any, siteId?: string)
+    determineNewState?(component: string, attemptId: number, question: any, componentId: string | number, siteId?: string)
         : CoreQuestionState | Promise<CoreQuestionState>;
 
     /**
@@ -74,15 +75,16 @@ export class CoreQuestionBehaviourDelegate extends CoreDelegate {
      * @param component Component the question belongs to.
      * @param attemptId Attempt ID the question belongs to.
      * @param question The question.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return Promise resolved with state.
      */
-    determineNewState(behaviour: string, component: string, attemptId: number, question: any, siteId?: string)
+    determineNewState(behaviour: string, component: string, attemptId: number, question: any, componentId: string | number,
-            : Promise<CoreQuestionState> {
+            siteId?: string): Promise<CoreQuestionState> {
         behaviour = this.questionDelegate.getBehaviourForQuestion(question, behaviour);
 
         return Promise.resolve(this.executeFunctionOnEnabled(behaviour, 'determineNewState',
-                [component, attemptId, question, siteId]));
+                [component, attemptId, question, componentId, siteId]));
     }
 
     /**

src/core/question/providers/delegate.ts

@@ -62,9 +62,11 @@ export interface CoreQuestionHandler extends CoreDelegateHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse?(question: any, answers: any): number;
+    isCompleteResponse?(question: any, answers: any, component: string, componentId: string | number): number;
 
     /**
      * Check if a student has provided enough of an answer for the question to be graded automatically,
@@ -72,9 +74,11 @@ export interface CoreQuestionHandler extends CoreDelegateHandler {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse?(question: any, answers: any): number;
+    isGradableResponse?(question: any, answers: any, component: string, componentId: string | number): number;
 
     /**
      * Check if two responses are the same.
@@ -84,7 +88,7 @@ export interface CoreQuestionHandler extends CoreDelegateHandler {
      * @param newAnswers Object with the new question answers.
      * @return Whether they're the same.
      */
-    isSameResponse?(question: any, prevAnswers: any, newAnswers: any): boolean;
+    isSameResponse?(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean;
 
     /**
      * Prepare and add to answers the data to send to server based in the input. Return promise if async.
@@ -92,10 +96,13 @@ export interface CoreQuestionHandler extends CoreDelegateHandler {
      * @param question Question.
      * @param answers The answers retrieved from the form. Prepared answers must be stored in this object.
      * @param offline Whether the data should be saved in offline.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return Return a promise resolved when done if async, void if sync.
      */
-    prepareAnswers?(question: any, answers: any, offline: boolean, siteId?: string): void | Promise<any>;
+    prepareAnswers?(question: any, answers: any, offline: boolean, component: string, componentId: string | number,
+            siteId?: string): void | Promise<any>;
 
     /**
      * Validate if an offline sequencecheck is valid compared with the online one.
@@ -115,6 +122,40 @@ export interface CoreQuestionHandler extends CoreDelegateHandler {
      * @return List of URLs.
      */
     getAdditionalDownloadableFiles?(question: any, usageId: number): string[];
+
+    /**
+     * Clear temporary data after the data has been saved.
+     *
+     * @param question Question.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @return If async, promise resolved when done.
+     */
+    clearTmpData?(question: any, component: string, componentId: string | number): void | Promise<void>;
+
+    /**
+     * Delete any stored data for the question.
+     *
+     * @param question Question.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @return If async, promise resolved when done.
+     */
+    deleteOfflineData?(question: any, component: string, componentId: string | number, siteId?: string): void | Promise<void>;
+
+    /**
+     * Prepare data to send when performing a synchronization.
+     *
+     * @param question Question.
+     * @param answers Answers of the question, without the prefix.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @return If async, promise resolved when done.
+     */
+    prepareSyncData?(question: any, answers: {[name: string]: any}, component: string, componentId: string | number,
+            siteId?: string): void | Promise<void>;
 }
 
 /**
@@ -196,12 +237,14 @@ export class CoreQuestionDelegate extends CoreDelegate {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if complete, 0 if not complete, -1 if cannot determine.
      */
-    isCompleteResponse(question: any, answers: any): number {
+    isCompleteResponse(question: any, answers: any, component: string, componentId: string | number): number {
         const type = this.getTypeName(question);
 
-        return this.executeFunctionOnEnabled(type, 'isCompleteResponse', [question, answers]);
+        return this.executeFunctionOnEnabled(type, 'isCompleteResponse', [question, answers, component, componentId]);
     }
 
     /**
@@ -210,12 +253,14 @@ export class CoreQuestionDelegate extends CoreDelegate {
      *
      * @param question The question.
      * @param answers Object with the question answers (without prefix).
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @return 1 if gradable, 0 if not gradable, -1 if cannot determine.
      */
-    isGradableResponse(question: any, answers: any): number {
+    isGradableResponse(question: any, answers: any, component: string, componentId: string | number): number {
         const type = this.getTypeName(question);
 
-        return this.executeFunctionOnEnabled(type, 'isGradableResponse', [question, answers]);
+        return this.executeFunctionOnEnabled(type, 'isGradableResponse', [question, answers, component, componentId]);
     }
 
     /**
@@ -226,10 +271,10 @@ export class CoreQuestionDelegate extends CoreDelegate {
      * @param newAnswers Object with the new question answers.
      * @return Whether they're the same.
      */
-    isSameResponse(question: any, prevAnswers: any, newAnswers: any): boolean {
+    isSameResponse(question: any, prevAnswers: any, newAnswers: any, component: string, componentId: string | number): boolean {
         const type = this.getTypeName(question);
 
-        return this.executeFunctionOnEnabled(type, 'isSameResponse', [question, prevAnswers, newAnswers]);
+        return this.executeFunctionOnEnabled(type, 'isSameResponse', [question, prevAnswers, newAnswers, component, componentId]);
     }
 
     /**
@@ -248,13 +293,17 @@ export class CoreQuestionDelegate extends CoreDelegate {
      * @param question Question.
      * @param answers The answers retrieved from the form. Prepared answers must be stored in this object.
      * @param offline Whether the data should be saved in offline.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return Promise resolved when data has been prepared.
      */
-    prepareAnswersForQuestion(question: any, answers: any, offline: boolean, siteId?: string): Promise<any> {
+    prepareAnswersForQuestion(question: any, answers: any, offline: boolean, component: string, componentId: string | number,
+            siteId?: string): Promise<any> {
         const type = this.getTypeName(question);
 
-        return Promise.resolve(this.executeFunctionOnEnabled(type, 'prepareAnswers', [question, answers, offline, siteId]));
+        return Promise.resolve(this.executeFunctionOnEnabled(type, 'prepareAnswers',
+                [question, answers, offline, component, componentId, siteId]));
     }
 
     /**
@@ -282,4 +331,50 @@ export class CoreQuestionDelegate extends CoreDelegate {
 
         return this.executeFunctionOnEnabled(type, 'getAdditionalDownloadableFiles', [question, usageId]) || [];
     }
+
+    /**
+     * Clear temporary data after the data has been saved.
+     *
+     * @param question Question.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @return If async, promise resolved when done.
+     */
+    clearTmpData(question: any, component: string, componentId: string | number): void | Promise<void> {
+        const type = this.getTypeName(question);
+
+        return this.executeFunctionOnEnabled(type, 'clearTmpData', [question, component, componentId]);
+    }
+
+    /**
+     * Clear temporary data after the data has been saved.
+     *
+     * @param question Question.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @return If async, promise resolved when done.
+     */
+    deleteOfflineData(question: any, component: string, componentId: string | number, siteId?: string): void | Promise<void> {
+        const type = this.getTypeName(question);
+
+        return this.executeFunctionOnEnabled(type, 'deleteOfflineData', [question, component, componentId, siteId]);
+    }
+
+    /**
+     * Prepare data to send when performing a synchronization.
+     *
+     * @param question Question.
+     * @param answers Answers of the question, without the prefix.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @return If async, promise resolved when done.
+     */
+    prepareSyncData?(question: any, answers: {[name: string]: any}, component: string, componentId: string | number,
+            siteId?: string): void | Promise<void> {
+        const type = this.getTypeName(question);
+
+        return this.executeFunctionOnEnabled(type, 'prepareSyncData', [question, answers, component, componentId, siteId]);
+    }
 }

src/core/question/providers/helper.ts

@@ -13,9 +13,12 @@
 // limitations under the License.
 
 import { Injectable, EventEmitter } from '@angular/core';
+import { FileEntry } from '@ionic-native/file';
 import { TranslateService } from '@ngx-translate/core';
+import { CoreFile } from '@providers/file';
 import { CoreFilepoolProvider } from '@providers/filepool';
 import { CoreSitesProvider } from '@providers/sites';
+import { CoreWSExternalFile } from '@providers/ws';
 import { CoreDomUtilsProvider } from '@providers/utils/dom';
 import { CoreTextUtilsProvider } from '@providers/utils/text';
 import { CoreUrlUtilsProvider } from '@providers/utils/url';
@@ -59,6 +62,41 @@ export class CoreQuestionHelperProvider {
         });
     }
 
+    /**
+     * Clear questions temporary data after the data has been saved.
+     *
+     * @param questions The list of questions.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @return Promise resolved when done.
+     */
+    async clearTmpData(questions: any[], component: string, componentId: string | number): Promise<void> {
+        questions = questions || [];
+
+        await Promise.all(questions.map(async (question) => {
+            await this.questionDelegate.clearTmpData(question, component, componentId);
+        }));
+    }
+
+    /**
+     * Delete files stored for a question.
+     *
+     * @param question Question.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when done.
+     */
+    async deleteStoredQuestionFiles(question: any, component: string, componentId: string | number, siteId?: string)
+            : Promise<void> {
+
+        const questionComponentId = this.questionProvider.getQuestionComponentId(question, componentId);
+        const folderPath = this.questionProvider.getQuestionFolder(question.type, component, questionComponentId, siteId);
+
+        // Ignore errors, maybe the folder doesn't exist.
+        await this.utils.ignoreErrors(CoreFile.instance.removeDir(folderPath));
+    }
+
     /**
      * Extract question behaviour submit buttons from the question's HTML and add them to "behaviourButtons" property.
      * The buttons aren't deleted from the content because all the im-controls block will be removed afterwards.
@@ -421,6 +459,41 @@ export class CoreQuestionHelperProvider {
         return state ? state.class : '';
     }
 
+    /**
+     * Return the files of a certain response file area.
+     *
+     * @param question Question.
+     * @param areaName Name of the area, e.g. 'attachments'.
+     * @return List of files.
+     */
+    getResponseFileAreaFiles(question: any, areaName: string): CoreWSExternalFile[] {
+        if (!question.responsefileareas) {
+            return [];
+        }
+
+        const area = question.responsefileareas.find((area) => {
+            return area.area == areaName;
+        });
+
+        return area && area.files || [];
+    }
+
+    /**
+     * Get files stored for a question.
+     *
+     * @param question Question.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved with the files.
+     */
+    getStoredQuestionFiles(question: any, component: string, componentId: string | number, siteId?: string): Promise<FileEntry[]> {
+        const questionComponentId = this.questionProvider.getQuestionComponentId(question, componentId);
+        const folderPath = this.questionProvider.getQuestionFolder(question.type, component, questionComponentId, siteId);
+
+        return CoreFile.instance.getDirectoryContents(folderPath);
+    }
+
     /**
      * Get the validation error message from a question HTML if it's there.
      *
@@ -521,7 +594,7 @@ export class CoreQuestionHelperProvider {
 
         if (!component) {
             component = CoreQuestionProvider.COMPONENT;
-            componentId = question.id;
+            componentId = question.number;
         }
 
         urls.push(...this.questionDelegate.getAdditionalDownloadableFiles(question, usageId));
@@ -552,15 +625,19 @@ export class CoreQuestionHelperProvider {
      * @param questions The list of questions.
      * @param answers The input data.
      * @param offline True if data should be saved in offline.
+     * @param component The component the question is related to.
+     * @param componentId Component ID.
      * @param siteId Site ID. If not defined, current site.
      * @return Promise resolved with answers to send to server.
      */
-    prepareAnswers(questions: any[], answers: any, offline?: boolean, siteId?: string): Promise<any> {
+    prepareAnswers(questions: any[], answers: any, offline: boolean, component: string, componentId: string | number,
+            siteId?: string): Promise<any> {
         const promises = [];
 
         questions = questions || [];
         questions.forEach((question) => {
-            promises.push(this.questionDelegate.prepareAnswersForQuestion(question, answers, offline, siteId));
+            promises.push(this.questionDelegate.prepareAnswersForQuestion(question, answers, offline, component, componentId,
+                    siteId));
         });
 
         return this.utils.allPromises(promises).then(() => {

src/core/question/providers/question.ts

@@ -13,10 +13,13 @@
 // limitations under the License.
 
 import { Injectable } from '@angular/core';
+import { CoreFile } from '@providers/file';
 import { CoreLoggerProvider } from '@providers/logger';
 import { CoreSitesProvider, CoreSiteSchema } from '@providers/sites';
+import { CoreTextUtils } from '@providers/utils/text';
 import { CoreTimeUtilsProvider } from '@providers/utils/time';
 import { CoreUtilsProvider } from '@providers/utils/utils';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * An object to represent a question state.
@@ -413,6 +416,35 @@ export class CoreQuestionProvider {
         });
     }
 
+    /**
+     * Given a question and a componentId, return a componentId that is unique for the question.
+     *
+     * @param question Question.
+     * @param componentId Component ID.
+     * @return Question component ID.
+     */
+    getQuestionComponentId(question: any, componentId: string | number): string {
+        return componentId + '_' + question.number;
+    }
+
+    /**
+     * Get the path to the folder where to store files for an offline question.
+     *
+     * @param type Question type.
+     * @param component Component the question is related to.
+     * @param componentId Question component ID, returned by getQuestionComponentId.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Folder path.
+     */
+    getQuestionFolder(type: string, component: string, componentId: string, siteId?: string): string {
+        siteId = siteId || this.sitesProvider.getCurrentSiteId();
+
+        const siteFolderPath = CoreFile.instance.getSiteFolder(siteId);
+        const questionFolderPath = 'offlinequestion/' + type + '/' + component + '/' + componentId;
+
+        return CoreTextUtils.instance.concatenatePaths(siteFolderPath, questionFolderPath);
+    }
+
     /**
      * Extract the question slot from a question name.
      *
@@ -612,3 +644,5 @@ export class CoreQuestionProvider {
         });
     }
 }
+
+export class CoreQuestion extends makeSingleton(CoreQuestionProvider) {}

src/lang/en.json

@@ -143,6 +143,7 @@
     "loadmore": "Load more",
     "location": "Location",
     "lostconnection": "Your authentication token is invalid or has expired. You will have to reconnect to the site.",
+    "maxfilesize": "Maximum size for new files: {{$a}}",
     "maxsizeandattachments": "Maximum file size: {{$a.size}}, maximum number of files: {{$a.attachments}}",
     "min": "min",
     "mins": "mins",

src/providers/file.ts

@@ -1114,10 +1114,8 @@ export class CoreFileProvider {
         // Get existing files in the folder.
         return this.getDirectoryContents(dirPath).then((entries) => {
             const files = {};
-            let num = 1,
+            let fileNameWithoutExtension = this.mimeUtils.removeExtension(fileName);
-                fileNameWithoutExtension = this.mimeUtils.removeExtension(fileName),
+            let extension = this.mimeUtils.getFileExtension(fileName) || defaultExt;
-                extension = this.mimeUtils.getFileExtension(fileName) || defaultExt,
-                newName;
 
             // Clean the file name.
             fileNameWithoutExtension = this.textUtils.removeSpecialCharactersForFiles(
@@ -1135,26 +1133,40 @@ export class CoreFileProvider {
                 extension = '';
             }
 
-            newName = fileNameWithoutExtension + extension;
+            return this.calculateUniqueName(files, fileNameWithoutExtension + extension);
-            if (typeof files[newName.toLowerCase()] == 'undefined') {
-                // No file with the same name.
-                return newName;
-            } else {
-                // Repeated name. Add a number until we find a free name.
-                do {
-                    newName = fileNameWithoutExtension + '(' + num + ')' + extension;
-                    num++;
-                } while (typeof files[newName.toLowerCase()] != 'undefined');
-
-                // Ask the user what he wants to do.
-                return newName;
-            }
         }).catch(() => {
             // Folder doesn't exist, name is unique. Clean it and return it.
             return this.textUtils.removeSpecialCharactersForFiles(this.textUtils.decodeURIComponent(fileName));
         });
     }
 
+    /**
+     * Given a file name and a set of already used names, calculate a unique name.
+     *
+     * @param usedNames Object with names already used as keys.
+     * @param name Name to check.
+     * @return Unique name.
+     */
+    calculateUniqueName(usedNames: {[name: string]: any}, name: string): string {
+        if (typeof usedNames[name.toLowerCase()] == 'undefined') {
+            // No file with the same name.
+            return name;
+        } else {
+            // Repeated name. Add a number until we find a free name.
+            const nameWithoutExtension = this.mimeUtils.removeExtension(name);
+            let extension = this.mimeUtils.getFileExtension(name);
+            let num = 1;
+            extension = extension ? '.' + extension : '';
+
+            do {
+                name = nameWithoutExtension + '(' + num + ')' + extension;
+                num++;
+            } while (typeof usedNames[name.toLowerCase()] != 'undefined');
+
+            return name;
+        }
+    }
+
     /**
      * Remove app temporary folder.
      *

src/providers/utils/text.ts

@@ -19,6 +19,7 @@ import { TranslateService } from '@ngx-translate/core';
 import { CoreLangProvider } from '../lang';
 import { makeSingleton } from '@singletons/core.singletons';
 import { CoreApp } from '../app';
+import { CoreWSExternalFile } from '../ws';
 
 /**
  * Different type of errors the app can treat.
@@ -699,6 +700,60 @@ export class CoreTextUtilsProvider {
         return text.replace(/(?:\r\n|\r|\n)/g, newValue);
     }
 
+    /**
+     * Replace draftfile URLs with the equivalent pluginfile URL.
+     *
+     * @param siteUrl URL of the site.
+     * @param text Text to treat, including draftfile URLs.
+     * @param files List of files of the area, using pluginfile URLs.
+     * @return Treated text and map with the replacements.
+     */
+    replaceDraftfileUrls(siteUrl: string, text: string, files: CoreWSExternalFile[])
+            : {text: string, replaceMap?: {[url: string]: string}} {
+
+        if (!text || !files || !files.length) {
+            return {text};
+        }
+
+        const draftfileUrl = this.concatenatePaths(siteUrl, 'draftfile.php');
+        const matches = text.match(new RegExp(this.escapeForRegex(draftfileUrl) + '[^\'" ]+', 'ig'));
+
+        if (!matches || !matches.length) {
+            return {text};
+        }
+
+        // Index the pluginfile URLs by file name.
+        const pluginfileMap: {[name: string]: string} = {};
+        files.forEach((file) => {
+            pluginfileMap[file.filename] = file.fileurl;
+        });
+
+        // Replace each draftfile with the corresponding pluginfile URL.
+        const replaceMap: {[url: string]: string} = {};
+        matches.forEach((url) => {
+            if (replaceMap[url]) {
+                // URL already treated, same file embedded more than once.
+                return;
+            }
+
+            // Get the filename from the URL.
+            let filename = url.substr(url.lastIndexOf('/') + 1);
+            if (filename.indexOf('?') != -1) {
+                filename = filename.substr(0, filename.indexOf('?'));
+            }
+
+            if (pluginfileMap[filename]) {
+                replaceMap[url] = pluginfileMap[filename];
+                text = text.replace(new RegExp(this.escapeForRegex(url), 'g'), pluginfileMap[filename]);
+            }
+        });
+
+        return {
+            text,
+            replaceMap,
+        };
+    }
+
     /**
      * Replace @@PLUGINFILE@@ wildcards with the real URL in a text.
      *
@@ -717,6 +772,36 @@ export class CoreTextUtilsProvider {
         return text;
     }
 
+    /**
+     * Restore original draftfile URLs.
+     *
+     * @param text Text to treat, including pluginfile URLs.
+     * @param replaceMap Map of the replacements that were done.
+     * @return Treated text.
+     */
+    restoreDraftfileUrls(siteUrl: string, treatedText: string, originalText: string, files: CoreWSExternalFile[]): string {
+        if (!treatedText || !files || !files.length) {
+            return treatedText;
+        }
+
+        const draftfileUrl = this.concatenatePaths(siteUrl, 'draftfile.php');
+        const draftfileUrlRegexPrefix = this.escapeForRegex(draftfileUrl) + '/[^/]+/[^/]+/[^/]+/[^/]+/';
+
+        files.forEach((file) => {
+            // Search the draftfile URL in the original text.
+            const matches = originalText.match(new RegExp(
+                    draftfileUrlRegexPrefix + this.escapeForRegex(file.filename) + '[^\'" ]*', 'i'));
+
+            if (!matches || !matches[0]) {
+                return; // Original URL not found, skip.
+            }
+
+            treatedText = treatedText.replace(new RegExp(this.escapeForRegex(file.fileurl), 'g'), matches[0]);
+        });
+
+        return treatedText;
+    }
+
     /**
      * Replace pluginfile URLs with @@PLUGINFILE@@ wildcards.
      *

src/providers/utils/url.ts

@@ -114,10 +114,10 @@ export class CoreUrlUtilsProvider {
      * @param url URL to treat.
      * @return Object with the params.
      */
-    extractUrlParams(url: string): any {
+    extractUrlParams(url: string): {[name: string]: string} {
         const regex = /[?&]+([^=&]+)=?([^&]*)?/gi,
             subParamsPlaceholder = '@@@SUBPARAMS@@@',
-            params: any = {},
+            params: {[name: string]: string} = {},
             urlAndHash = url.split('#'),
             questionMarkSplit = urlAndHash[0].split('?');
         let subParams;

upgrade.txt

@@ -1,6 +1,10 @@
 This files describes API changes in the Moodle Mobile app,
 information provided here is intended especially for developers.
 
+=== 3.9.3 ===
+
+- In the core-attachments component, passing a -1 as maxSize or maxSubmissions used to mean "unknown limit". Now -1 means unlimited.
+
 === 3.8.3 ===
 
 - CoreFileProvider.writeFileDataInFile has been deprecated. Please use CoreFileHelperProvider.writeFileDataInFile instead.