MOBILE-3654 survey: Add survey activity module

src/addons/mod/mod.module.ts

@@ -27,6 +27,7 @@ import { AddonModResourceModule } from './resource/resource.module';
 import { AddonModUrlModule } from './url/url.module';
 import { AddonModLtiModule } from './lti/lti.module';
 import { AddonModH5PActivityModule } from './h5pactivity/h5pactivity.module';
+import { AddonModSurveyModule } from './survey/survey.module';
 
 @NgModule({
     declarations: [],
@@ -44,6 +45,7 @@ import { AddonModH5PActivityModule } from './h5pactivity/h5pactivity.module';
         AddonModImscpModule,
         AddonModLtiModule,
         AddonModH5PActivityModule,
+        AddonModSurveyModule,
     ],
     providers: [],
     exports: [],

src/addons/mod/survey/components/components.module.ts

@@ -0,0 +1,32 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { NgModule } from '@angular/core';
+import { AddonModSurveyIndexComponent } from './index/index';
+import { CoreSharedModule } from '@/core/shared.module';
+import { CoreCourseComponentsModule } from '@features/course/components/components.module';
+
+@NgModule({
+    declarations: [
+        AddonModSurveyIndexComponent,
+    ],
+    imports: [
+        CoreSharedModule,
+        CoreCourseComponentsModule,
+    ],
+    exports: [
+        AddonModSurveyIndexComponent,
+    ],
+})
+export class AddonModSurveyComponentsModule {}

src/addons/mod/survey/components/index/addon-mod-survey-index.html

@@ -0,0 +1,152 @@
+<!-- Buttons to add to the header. -->
+<core-navbar-buttons slot="end">
+    <core-context-menu>
+        <core-context-menu-item *ngIf="externalUrl" [priority]="900" [content]="'core.openinbrowser' | translate"
+            [href]="externalUrl" iconAction="fas-external-link-alt">
+        </core-context-menu-item>
+        <core-context-menu-item *ngIf="description" [priority]="800" [content]="'core.moduleintro' | translate"
+            (action)="expandDescription()" iconAction="fas-arrow-right">
+        </core-context-menu-item>
+        <core-context-menu-item *ngIf="blog" [priority]="750" content="{{'addon.blog.blog' | translate}}"
+            iconAction="far-newspaper" (action)="gotoBlog()">
+        </core-context-menu-item>
+        <core-context-menu-item *ngIf="loaded && !hasOffline && isOnline" [priority]="700" [content]="'core.refresh' | translate"
+            (action)="doRefresh(null, $event)" [iconAction]="refreshIcon" [closeOnClick]="false">
+        </core-context-menu-item>
+        <core-context-menu-item *ngIf="loaded && hasOffline && isOnline"  [priority]="600"
+            [content]="'core.settings.synchronizenow' | translate" (action)="doRefresh(null, $event, true)"
+            [iconAction]="syncIcon" [closeOnClick]="false">
+        </core-context-menu-item>
+        <core-context-menu-item *ngIf="prefetchStatusIcon" [priority]="500" [content]="prefetchText" (action)="prefetch($event)"
+            [iconAction]="prefetchStatusIcon" [closeOnClick]="false">
+        </core-context-menu-item>
+        <core-context-menu-item *ngIf="size" [priority]="400" [content]="'core.clearstoreddata' | translate:{$a: size}"
+            iconDescription="fas-archive" (action)="removeFiles($event)" iconAction="fas-trash" [closeOnClick]="false">
+        </core-context-menu-item>
+    </core-context-menu>
+</core-navbar-buttons>
+
+<!-- Content. -->
+<core-loading [hideUntil]="loaded" class="core-loading-center safe-area-page">
+
+    <core-course-module-description *ngIf="survey && !survey.surveydone && !hasOffline" [description]="description"
+        [component]="component" [componentId]="componentId" contextLevel="module" [contextInstanceId]="module.id"
+        [courseId]="courseId">
+    </core-course-module-description>
+
+    <!-- Survey already done -->
+    <ion-card class="ion-padding" *ngIf="survey && survey.surveydone">
+        <p class="ion-padding">{{ 'addon.mod_survey.surveycompletednograph' | translate }}</p>
+        <ion-button expand="block" [href]="externalUrl" core-link>
+            <ion-icon name="fas-external-link-alt" slot="start"></ion-icon>
+            {{ 'addon.mod_survey.results' | translate }}
+        </ion-button>
+    </ion-card>
+
+    <!-- Survey done in offline but not synchronized -->
+    <ion-card class="core-warning-card" *ngIf="hasOffline">
+        <ion-item>
+            <ion-icon name="fas-exclamation-triangle" slot="start"></ion-icon>
+            <ion-label>{{ 'core.hasdatatosync' | translate: {$a: moduleName} }}</ion-label>
+        </ion-item>
+    </ion-card>
+
+    <!-- Survey questions -->
+    <form *ngIf="survey && !survey.surveydone && !hasOffline && questions && questions.length">
+
+        <ion-grid class="ion-no-padding ion-text-wrap">
+            <ng-container *ngFor="let question of questions; let questionIndex=index; let isEven=even;" class="ion-no-padding ion-text-wrap">
+                <!-- Parent question (Category header) -->
+                <ng-container *ngIf="question.multiArray?.length" >
+                    <h3 class="ion-padding-horizontal" [class.ion-padding-top]="questionIndex == 1">{{ question.text }}</h3>
+                    <ion-row class="ion-align-items-center ion-hide-md-down ion-padding">
+                        <ion-col size="7" class="ion-padding">{{ 'addon.mod_survey.responses' | translate }}</ion-col>
+                        <ion-col size="1" class="ion-text-center option-name"
+                            *ngFor="let option of question.optionsArray; let indexOption=index;">
+                            {{ option }}
+                        </ion-col>
+                    </ion-row>
+                    <ion-item class="ion-text-wrap addon-mod_survey-question" [class.even]="isEven" lines="full">
+                        <ion-label><p>{{ question.intro }}</p></ion-label>
+                    </ion-item>
+                </ng-container>
+
+                <!-- Subquestion -->
+                <ion-radio-group [(ngModel)]="answers[question.name]" [required]="question.required" [name]="question.name">
+                    <ion-row *ngIf="question.parent !== 0" class="ion-align-items-center ion-padding" [class.even]="isEven">
+
+                        <ion-col size="7">
+                            <ion-label id="addon-mod_survey-{{question.id}}">
+                                <span [core-mark-required]="question.required">
+                                    <strong>{{question.num}}.</strong> {{ question.text }}
+                                </span>
+                            </ion-label>
+                        </ion-col>
+
+                        <!-- Tablet view: radio buttons -->
+                        <ion-col class="ion-hide-md-down ion-text-center" size="1"
+                            *ngFor="let option of question.optionsArray; let value=index;">
+                            <!-- Empty slot to avoid errors on migration tslint checks -->
+                            <ion-radio [value]="value + 1" [attr.aria-labelledby]="'addon-mod_survey-'+question.id" slot="">
+                            </ion-radio>
+                        </ion-col>
+                        <ion-col class="ion-hide-md-up" size="5">
+                            <ion-select class="ion-padding" [(ngModel)]="answers[question.name]" [required]="question.required"
+                                [attr.aria-labelledby]="'addon-mod_survey-'+question.id" interface="action-sheet"
+                                [name]="question.name">
+                                <ion-select-option value="-1" selected disabled>{{ 'core.choose' | translate }}</ion-select-option>
+                                <ion-select-option *ngFor="let option of question.optionsArray; let value=index;"
+                                    [value]="value +1">
+                                    {{option}}
+                                </ion-select-option>
+                            </ion-select>
+                        </ion-col>
+                    </ion-row>
+                </ion-radio-group>
+
+                <!-- Single question (don't belong to a category) -->
+                <ng-container *ngIf="(!question.multiArray || question.multiArray.length == 0) && question.parent === 0">
+                    <ion-row class="ion-align-items-center ion-padding" *ngIf="question.type > 0" [class.even]="isEven">
+                        <ion-col size="7">
+                            <ion-label id="addon-mod_survey-{{question.id}}">
+                                <span [core-mark-required]="question.required">
+                                    <strong>{{question.num}}.</strong> {{ question.text }}
+                                </span>
+                            </ion-label>
+                        </ion-col>
+                        <ion-col size="5">
+                            <ion-select class="ion-padding" [(ngModel)]="answers[question.name]" [required]="question.required"
+                                [attr.aria-labelledby]="'addon-mod_survey-'+question.id" interface="action-sheet"
+                                [name]="question.name">
+                                <ion-select-option *ngFor="let option of question.optionsArray; let value=index;" [value]="value">
+                                    {{option}}
+                                </ion-select-option>
+                            </ion-select>
+                        </ion-col>
+                    </ion-row>
+
+                    <ion-item *ngIf="question.type === 0" class="ion-text-wrap" [class.even]="isEven">
+                        <ion-label position="floating" id="addon-mod_survey-{{question.id}}">
+                            <span [core-mark-required]="question.required">
+                                <strong>{{question.num}}.</strong> {{ question.text }}
+                            </span>
+                        </ion-label>
+                        <ion-textarea [(ngModel)]="answers[question.name]" [name]="question.name"
+                            [attr.aria-labelledby]="'addon-mod_survey-'+question.id" [required]="question.required">
+                        </ion-textarea>
+                    </ion-item>
+                </ng-container>
+
+            </ng-container>
+        </ion-grid>
+
+        <ion-item>
+            <ion-label>
+                <ion-button expand="block" (click)="submit()" [disabled]="!isValidResponse()">
+                    {{ 'core.submit' | translate }}
+                </ion-button>
+            </ion-label>
+        </ion-item>
+    </form>
+
+</core-loading>

src/addons/mod/survey/components/index/index.scss

@@ -0,0 +1,25 @@
+:host {
+    --grid-background: var(--white);
+    --even-background: var(--gray-light);
+
+    .option-name {
+        font-size: 14px;
+    }
+
+    .addon-mod_survey-question {
+        border-top: 1px solid var(--gray);
+    }
+
+    ion-row {
+        background-color: var(--grid-background);
+    }
+
+    .even {
+        background-color: var(--even-background);
+    }
+}
+
+:host-context(body.dark) {
+    --grid-background: var(--black);
+    --even-background: var(--gray-darker);
+}

src/addons/mod/survey/components/index/index.ts

@@ -0,0 +1,250 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Component, OnInit, Optional } from '@angular/core';
+import { CoreIonLoadingElement } from '@classes/ion-loading';
+import { CoreCourseModuleMainActivityComponent } from '@features/course/classes/main-activity-component';
+import { CoreCourseContentsPage } from '@features/course/pages/contents/contents';
+import { CoreCourse } from '@features/course/services/course';
+import { IonContent } from '@ionic/angular';
+import { CoreSites } from '@services/sites';
+import { CoreDomUtils } from '@services/utils/dom';
+import { CoreTextUtils } from '@services/utils/text';
+import { Translate } from '@singletons';
+import { CoreEvents } from '@singletons/events';
+import { AddonModSurveyPrefetchHandler } from '../../services/handlers/prefetch';
+import {
+    AddonModSurveyProvider,
+    AddonModSurveySurvey,
+    AddonModSurvey,
+    AddonModSurveySubmitAnswerData,
+} from '../../services/survey';
+import { AddonModSurveyHelper, AddonModSurveyQuestionFormatted } from '../../services/survey-helper';
+import { AddonModSurveyOffline } from '../../services/survey-offline';
+import { AddonModSurveyAutoSyncData, AddonModSurveySync, AddonModSurveySyncResult } from '../../services/survey-sync';
+
+/**
+ * Component that displays a survey.
+ */
+@Component({
+    selector: 'addon-mod-survey-index',
+    templateUrl: 'addon-mod-survey-index.html',
+    styleUrls: ['index.scss'],
+})
+export class AddonModSurveyIndexComponent extends CoreCourseModuleMainActivityComponent implements OnInit {
+
+    component = AddonModSurveyProvider.COMPONENT;
+    moduleName = 'survey';
+
+    survey?: AddonModSurveySurvey;
+    questions: AddonModSurveyQuestionFormatted[] = [];
+    answers: Record<string, string> = {};
+
+    protected currentUserId?: number;
+
+    constructor(
+        protected content?: IonContent,
+        @Optional() courseContentsPage?: CoreCourseContentsPage,
+    ) {
+        super('AddonModSurveyIndexComponent', content, courseContentsPage);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    async ngOnInit(): Promise<void> {
+        super.ngOnInit();
+
+        this.currentUserId = CoreSites.getCurrentSiteUserId();
+
+        await this.loadContent(false, true);
+
+        try {
+            await AddonModSurvey.logView(this.survey!.id, this.survey!.name);
+            CoreCourse.checkModuleCompletion(this.courseId, this.module.completiondata);
+        } catch {
+            // Ignore errors. Just don't check Module completion.
+        }
+    }
+
+    /**
+     * Perform the invalidate content function.
+     *
+     * @return Resolved when done.
+     */
+    protected async invalidateContent(): Promise<void> {
+        const promises: Promise<void>[] = [];
+
+        promises.push(AddonModSurvey.invalidateSurveyData(this.courseId));
+        if (this.survey) {
+            promises.push(AddonModSurvey.invalidateQuestions(this.survey.id));
+        }
+
+        await Promise.all(promises);
+    }
+
+    /**
+     * Compares sync event data with current data to check if refresh content is needed.
+     *
+     * @param syncEventData Data receiven on sync observer.
+     * @return True if refresh is needed, false otherwise.
+     */
+    protected isRefreshSyncNeeded(syncEventData: AddonModSurveyAutoSyncData): boolean {
+        if (this.survey && syncEventData.surveyId == this.survey.id && syncEventData.userId == this.currentUserId) {
+            return true;
+        }
+
+        return false;
+    }
+
+    /**
+     * Download survey contents.
+     *
+     * @param refresh If it's refreshing content.
+     * @param sync If it should try to sync.
+     * @param showErrors If show errors to the user of hide them.
+     * @return Promise resolved when done.
+     */
+    protected async fetchContent(refresh: boolean = false, sync: boolean = false, showErrors: boolean = false): Promise<void> {
+        try {
+            this.survey = await AddonModSurvey.getSurvey(this.courseId, this.module.id);
+
+            this.description = this.survey.intro;
+            this.dataRetrieved.emit(this.survey);
+
+            if (sync) {
+                // Try to synchronize the survey.
+                const answersSent = await this.syncActivity(showErrors);
+                if (answersSent) {
+                    // Answers were sent, update the survey.
+                    this.survey = await AddonModSurvey.getSurvey(this.courseId, this.module.id);
+                }
+            }
+
+            // Check if there are answers stored in offline.
+            this.hasOffline = this.survey.surveydone
+                ? false
+                : await AddonModSurveyOffline.hasAnswers(this.survey.id);
+
+            if (!this.survey.surveydone && !this.hasOffline) {
+                await this.fetchQuestions();
+            }
+        } finally {
+            this.fillContextMenu(refresh);
+        }
+    }
+
+    /**
+     * Convenience function to get survey questions.
+     *
+     * @return Promise resolved when done.
+     */
+    protected async fetchQuestions(): Promise<void> {
+        const questions = await AddonModSurvey.getQuestions(this.survey!.id, { cmId: this.module.id });
+
+        this.questions = AddonModSurveyHelper.formatQuestions(questions);
+
+        // Init answers object.
+        this.questions.forEach((question) => {
+            if (question.name) {
+                const isTextArea = question.multiArray && question.multiArray.length === 0 && question.type === 0;
+                this.answers[question.name] = question.required ? '-1' : (isTextArea ? '' : '0');
+            }
+
+            if (question.multiArray && !question.multiArray.length && question.parent === 0 && question.type > 0) {
+                // Options shown in a select. Remove all HTML.
+                question.optionsArray = question.optionsArray?.map((option) => CoreTextUtils.cleanTags(option));
+            }
+        });
+    }
+
+    /**
+     * Check if answers are valid to be submitted.
+     *
+     * @return If answers are valid
+     */
+    isValidResponse(): boolean {
+        return !this.questions.some((question) => question.required && question.name &&
+            (question.type === 0 ? this.answers[question.name] == '' : parseInt(this.answers[question.name], 10) === -1));
+    }
+
+    /**
+     * Save options selected.
+     */
+    async submit(): Promise<void> {
+        let modal: CoreIonLoadingElement | undefined;
+
+        try {
+            await CoreDomUtils.showConfirm(Translate.instant('core.areyousure'));
+
+            const answers: AddonModSurveySubmitAnswerData[] = [];
+            modal = await CoreDomUtils.showModalLoading('core.sending', true);
+
+            for (const x in this.answers) {
+                answers.push({
+                    key: x,
+                    value: this.answers[x],
+                });
+            }
+
+            const online = await AddonModSurvey.submitAnswers(this.survey!.id, this.survey!.name, this.courseId, answers);
+
+            CoreEvents.trigger(CoreEvents.ACTIVITY_DATA_SENT, { module: this.moduleName });
+
+            if (online && this.isPrefetched()) {
+                // The survey is downloaded, update the data.
+                try {
+                    await AddonModSurveySync.prefetchAfterUpdate(
+                        AddonModSurveyPrefetchHandler.instance,
+                        this.module,
+                        this.courseId,
+                    );
+
+                    // Update the view.
+                    this.showLoadingAndFetch(false, false);
+                } catch {
+                    // Prefetch failed, refresh the data.
+                    await this.showLoadingAndRefresh(false);
+                }
+            } else {
+                // Not downloaded, refresh the data.
+                await this.showLoadingAndRefresh(false);
+            }
+        } catch (error) {
+            CoreDomUtils.showErrorModalDefault(error, 'addon.mod_survey.cannotsubmitsurvey', true);
+        } finally {
+            modal?.dismiss();
+        }
+    }
+
+    /**
+     * Performs the sync of the activity.
+     *
+     * @return Promise resolved when done.
+     */
+    protected async sync(): Promise<void> {
+        await AddonModSurveySync.syncSurvey(this.survey!.id, this.currentUserId);
+    }
+
+    /**
+     * Checks if sync has succeed from result sync data.
+     *
+     * @param result Data returned on the sync function.
+     * @return If suceed or not.
+     */
+    protected hasSyncSucceed(result: AddonModSurveySyncResult): boolean {
+        return result.answersSent;
+    }
+
+}

src/addons/mod/survey/lang.json

@@ -0,0 +1,10 @@
+{
+    "cannotsubmitsurvey": "Sorry, there was a problem submitting your survey. Please try again.",
+    "errorgetsurvey": "Error getting survey data.",
+    "ifoundthat": "I found that",
+    "ipreferthat": "I prefer that",
+    "modulenameplural": "Surveys",
+    "responses": "Responses",
+    "results": "Results",
+    "surveycompletednograph": "You have completed this survey."
+}

src/addons/mod/survey/pages/index/index.html

@@ -0,0 +1,19 @@
+<ion-header>
+    <ion-toolbar>
+        <ion-buttons slot="start">
+            <ion-back-button [attr.aria-label]="'core.back' | translate"></ion-back-button>
+        </ion-buttons>
+        <ion-title><core-format-text [text]="title" contextLevel="module" [contextInstanceId]="module.id"></core-format-text></ion-title>
+
+        <ion-buttons slot="end">
+            <!-- The buttons defined by the component will be added in here. -->
+        </ion-buttons>
+    </ion-toolbar>
+</ion-header>
+<ion-content>
+    <ion-refresher slot="fixed" [disabled]="!activityComponent?.loaded" (ionRefresh)="activityComponent?.doRefresh($event.target)">
+        <ion-refresher-content pullingText="{{ 'core.pulltorefresh' | translate }}"></ion-refresher-content>
+    </ion-refresher>
+
+    <addon-mod-survey-index [module]="module" [courseId]="courseId" (dataRetrieved)="updateData($event)"></addon-mod-survey-index>
+</ion-content>

src/addons/mod/survey/pages/index/index.ts

@@ -0,0 +1,30 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Component, ViewChild } from '@angular/core';
+import { CoreCourseModuleMainActivityPage } from '@features/course/classes/main-activity-page';
+import { AddonModSurveyIndexComponent } from '../../components/index';
+
+/**
+ * Page that displays a survey.
+ */
+@Component({
+    selector: 'page-addon-mod-survey-index',
+    templateUrl: 'index.html',
+})
+export class AddonModSurveyIndexPage extends CoreCourseModuleMainActivityPage<AddonModSurveyIndexComponent> {
+
+    @ViewChild(AddonModSurveyIndexComponent) activityComponent?: AddonModSurveyIndexComponent;
+
+}

src/addons/mod/survey/services/database/survey.ts

@@ -0,0 +1,68 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { CoreSiteSchema } from '@services/sites';
+
+/**
+ * Database variables for AddonModSurveyOfflineProvider.
+ */
+export const SURVEY_TABLE = 'addon_mod_survey_answers';
+export const ADDON_MOD_SURVEY_OFFLINE_SITE_SCHEMA: CoreSiteSchema = {
+    name: 'AddonModSurveyOfflineProvider',
+    version: 1,
+    tables: [
+        {
+            name: SURVEY_TABLE,
+            columns: [
+                {
+                    name: 'surveyid',
+                    type: 'INTEGER',
+                },
+                {
+                    name: 'name',
+                    type: 'TEXT',
+                },
+                {
+                    name: 'courseid',
+                    type: 'INTEGER',
+                },
+                {
+                    name: 'userid',
+                    type: 'INTEGER',
+                },
+                {
+                    name: 'answers',
+                    type: 'TEXT',
+                },
+                {
+                    name: 'timecreated',
+                    type: 'INTEGER',
+                },
+            ],
+            primaryKeys: ['surveyid', 'userid'],
+        },
+    ],
+};
+
+/**
+ * Survey offline answers.
+ */
+export type AddonModSurveyAnswersDBRecord = {
+    surveyid: number;
+    userid: number;
+    name: string;
+    courseid: number;
+    answers: string;
+    timecreated: number;
+};

src/addons/mod/survey/services/handlers/index-link.ts

@@ -0,0 +1,32 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Injectable } from '@angular/core';
+import { CoreContentLinksModuleIndexHandler } from '@features/contentlinks/classes/module-index-handler';
+import { makeSingleton } from '@singletons';
+
+/**
+ * Handler to treat links to survey.
+ */
+@Injectable( { providedIn: 'root' })
+export class AddonModSurveyIndexLinkHandlerService extends CoreContentLinksModuleIndexHandler {
+
+    name = 'AddonModSurveyLinkHandler';
+
+    constructor() {
+        super('AddonModSurvey', 'survey');
+    }
+
+}
+export const AddonModSurveyIndexLinkHandler = makeSingleton(AddonModSurveyIndexLinkHandlerService);

src/addons/mod/survey/services/handlers/list-link.ts

@@ -0,0 +1,32 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Injectable } from '@angular/core';
+import { CoreContentLinksModuleListHandler } from '@features/contentlinks/classes/module-list-handler';
+import { makeSingleton } from '@singletons';
+
+/**
+ * Handler to treat links to survey list page.
+ */
+@Injectable( { providedIn: 'root' })
+export class AddonModSurveyListLinkHandlerService extends CoreContentLinksModuleListHandler {
+
+    name = 'AddonModSurveyListLinkHandler';
+
+    constructor() {
+        super('AddonModSurvey', 'survey');
+    }
+
+}
+export const AddonModSurveyListLinkHandler = makeSingleton(AddonModSurveyListLinkHandlerService);

src/addons/mod/survey/services/handlers/module.ts

@@ -0,0 +1,84 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { CoreConstants } from '@/core/constants';
+import { Injectable, Type } from '@angular/core';
+import { CoreCourse, CoreCourseAnyModuleData } from '@features/course/services/course';
+import { CoreCourseModule } from '@features/course/services/course-helper';
+import { CoreCourseModuleHandler, CoreCourseModuleHandlerData } from '@features/course/services/module-delegate';
+import { CoreNavigationOptions, CoreNavigator } from '@services/navigator';
+import { makeSingleton } from '@singletons';
+import { AddonModSurveyIndexComponent } from '../../components/index';
+
+/**
+ * Handler to support survey modules.
+ */
+@Injectable( { providedIn: 'root' })
+export class AddonModSurveyModuleHandlerService implements CoreCourseModuleHandler {
+
+    static readonly PAGE_NAME = 'mod_survey';
+
+    name = 'AddonModSurvey';
+    modName = 'survey';
+
+    supportedFeatures = {
+        [CoreConstants.FEATURE_GROUPS]: true,
+        [CoreConstants.FEATURE_GROUPINGS]: true,
+        [CoreConstants.FEATURE_MOD_INTRO]: true,
+        [CoreConstants.FEATURE_COMPLETION_TRACKS_VIEWS]: true,
+        [CoreConstants.FEATURE_COMPLETION_HAS_RULES]: true,
+        [CoreConstants.FEATURE_GRADE_HAS_GRADE]: false,
+        [CoreConstants.FEATURE_GRADE_OUTCOMES]: false,
+        [CoreConstants.FEATURE_BACKUP_MOODLE2]: true,
+        [CoreConstants.FEATURE_SHOW_DESCRIPTION]: true,
+    };
+
+    /**
+     * @inheritdoc
+     */
+    async isEnabled(): Promise<boolean> {
+        return true;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    getData(
+        module: CoreCourseAnyModuleData,
+    ): CoreCourseModuleHandlerData {
+        return {
+            icon: CoreCourse.getModuleIconSrc(this.modName, 'modicon' in module ? module.modicon : undefined),
+            title: module.name,
+            class: 'addon-mod_survey-handler',
+            showDownloadButton: true,
+            action: (event: Event, module: CoreCourseModule, courseId: number, options?: CoreNavigationOptions) => {
+                options = options || {};
+                options.params = options.params || {};
+                Object.assign(options.params, { module });
+                const routeParams = '/' + courseId + '/' + module.id;
+
+                CoreNavigator.navigateToSitePath(AddonModSurveyModuleHandlerService.PAGE_NAME + routeParams, options);
+            },
+        };
+    }
+
+    /**
+     * @inheritdoc
+     */
+    async getMainComponent(): Promise<Type<unknown>> {
+        return AddonModSurveyIndexComponent;
+    }
+
+}
+export const AddonModSurveyModuleHandler = makeSingleton(AddonModSurveyModuleHandlerService);

src/addons/mod/survey/services/handlers/prefetch.ts

@@ -0,0 +1,114 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Injectable } from '@angular/core';
+import { CoreCourseActivityPrefetchHandlerBase } from '@features/course/classes/activity-prefetch-handler';
+import { CoreCourseAnyModuleData } from '@features/course/services/course';
+import { CoreFilepool } from '@services/filepool';
+import { CoreSitesReadingStrategy } from '@services/sites';
+import { CoreUtils } from '@services/utils/utils';
+import { CoreWSExternalFile } from '@services/ws';
+import { makeSingleton } from '@singletons';
+import { AddonModSurvey, AddonModSurveyProvider } from '../survey';
+import { AddonModSurveySync, AddonModSurveySyncResult } from '../survey-sync';
+
+/**
+ * Handler to prefetch surveys.
+ */
+@Injectable( { providedIn: 'root' })
+export class AddonModSurveyPrefetchHandlerService extends CoreCourseActivityPrefetchHandlerBase {
+
+    name = 'AddonModSurvey';
+    modName = 'survey';
+    component = AddonModSurveyProvider.COMPONENT;
+    updatesNames = /^configuration$|^.*files$|^answers$/;
+
+    /**
+     * @inheritdoc
+     */
+    async getIntroFiles(module: CoreCourseAnyModuleData, courseId: number): Promise<CoreWSExternalFile[]> {
+        const survey = await CoreUtils.ignoreErrors(AddonModSurvey.getSurvey(courseId, module.id));
+
+        return this.getIntroFilesFromInstance(module, survey);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    async invalidateContent(moduleId: number, courseId: number): Promise<void> {
+        return AddonModSurvey.invalidateContent(moduleId, courseId);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    async invalidateModule(module: CoreCourseAnyModuleData, courseId: number): Promise<void> {
+        await AddonModSurvey.invalidateSurveyData(courseId);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    async isEnabled(): Promise<boolean> {
+        return true;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    prefetch(module: CoreCourseAnyModuleData, courseId?: number): Promise<void> {
+        return this.prefetchPackage(module, courseId, this.prefetchSurvey.bind(this, module, courseId));
+    }
+
+    /**
+     * Prefetch a survey.
+     *
+     * @param module Module.
+     * @param courseId Course ID the module belongs to.
+     * @param siteId SiteId or current site.
+     * @return Promise resolved when done.
+     */
+    protected async prefetchSurvey(module: CoreCourseAnyModuleData, courseId: number, siteId: string): Promise<void> {
+        const survey = await AddonModSurvey.getSurvey(courseId, module.id, {
+            readingStrategy: CoreSitesReadingStrategy.OnlyNetwork,
+            siteId,
+        });
+
+        const promises: Promise<unknown>[] = [];
+        const files = this.getIntroFilesFromInstance(module, survey);
+
+        // Prefetch files.
+        promises.push(CoreFilepool.addFilesToQueue(siteId, files, AddonModSurveyProvider.COMPONENT, module.id));
+
+        // If survey isn't answered, prefetch the questions.
+        if (!survey.surveydone) {
+            promises.push(AddonModSurvey.getQuestions(survey.id, {
+                cmId: module.id,
+                readingStrategy: CoreSitesReadingStrategy.OnlyNetwork,
+                siteId,
+            }));
+        }
+
+        await Promise.all(promises);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    sync(module: CoreCourseAnyModuleData, courseId: number, siteId?: string): Promise<AddonModSurveySyncResult> {
+        return AddonModSurveySync.syncSurvey(module.instance!, undefined, siteId);
+    }
+
+}
+export const AddonModSurveyPrefetchHandler = makeSingleton(AddonModSurveyPrefetchHandlerService);

src/addons/mod/survey/services/handlers/sync-cron.ts

@@ -0,0 +1,43 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Injectable } from '@angular/core';
+import { CoreCronHandler } from '@services/cron';
+import { makeSingleton } from '@singletons';
+import { AddonModSurveySync } from '../survey-sync';
+
+/**
+ * Synchronization cron handler.
+ */
+@Injectable( { providedIn: 'root' })
+export class AddonModSurveySyncCronHandlerService implements CoreCronHandler {
+
+    name = 'AddonModSurveySyncCronHandler';
+
+    /**
+     * @inheritdoc
+     */
+    async execute(siteId?: string, force?: boolean): Promise<void> {
+        await AddonModSurveySync.syncAllSurveys(siteId, force);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    getInterval(): number {
+        return AddonModSurveySync.syncInterval;
+    }
+
+}
+export const AddonModSurveySyncCronHandler = makeSingleton(AddonModSurveySyncCronHandlerService);

src/addons/mod/survey/services/survey-helper.ts

@@ -0,0 +1,138 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Injectable } from '@angular/core';
+import { makeSingleton, Translate } from '@singletons';
+import { AddonModSurveyQuestion } from './survey';
+
+/**
+ * Service that provides helper functions for surveys.
+ */
+@Injectable( { providedIn: 'root' })
+export class AddonModSurveyHelperProvider {
+
+    /**
+     * Turns a string with values separated by commas into an array.
+     *
+     * @param value Value to convert.
+     * @return Array.
+     */
+    protected commaStringToArray(value: string | string[]): string[] {
+        if (typeof value == 'string') {
+            if (value.length > 0) {
+                return value.split(',');
+            }
+
+            return [];
+        }
+
+        return value;
+    }
+
+    /**
+     * Gets the parent questions and puts them in an object: ID -> question.
+     *
+     * @param questions Questions.
+     * @return Object with parent questions.
+     */
+    protected getParentQuestions(questions: AddonModSurveyQuestion[]): {[id: number]: AddonModSurveyQuestion} {
+        const parents: { [id: number]: AddonModSurveyQuestion } = {};
+
+        questions.forEach((question) => {
+            if (question.parent === 0) {
+                parents[question.id] = question;
+            }
+        });
+
+        return parents;
+    }
+
+    /**
+     * Format a questions list, turning "multi" and "options" strings into arrays and adding the properties
+     * 'num' and 'name'.
+     *
+     * @param questions Questions.
+     * @return Promise resolved with the formatted questions.
+     */
+    formatQuestions(questions: AddonModSurveyQuestion[]): AddonModSurveyQuestionFormatted[] {
+        const strIPreferThat = Translate.instant('addon.mod_survey.ipreferthat');
+        const strIFoundThat = Translate.instant('addon.mod_survey.ifoundthat');
+        const strChoose = Translate.instant('core.choose');
+
+        const formatted: AddonModSurveyQuestionFormatted[] = [];
+        const parents = this.getParentQuestions(questions);
+
+        let num = 1;
+
+        questions.forEach((question) => {
+            // Copy the object to prevent modifying the original.
+            const q1: AddonModSurveyQuestionFormatted = Object.assign({}, question);
+            const parent = parents[q1.parent];
+
+            // Turn multi and options into arrays.
+            q1.multiArray = this.commaStringToArray(q1.multi);
+            q1.optionsArray = this.commaStringToArray(q1.options);
+
+            if (parent) {
+                // It's a sub-question.
+                q1.required = true;
+
+                if (parent.type === 1 || parent.type === 2) {
+                    // One answer question. Set its name and add it to the returned array.
+                    q1.name = 'q' + (parent.type == 2 ? 'P' : '') + q1.id;
+                    q1.num = num++;
+                } else {
+                    // Two answers per question (COLLES P&A). We'll add two questions.
+                    const q2 = Object.assign({}, q1);
+
+                    q1.text = strIPreferThat + ' ' + q1.text;
+                    q1.name = 'qP' + q1.id;
+                    q1.num = num++;
+                    formatted.push(q1);
+
+                    q2.text = strIFoundThat + ' ' + q2.text;
+                    q2.name = 'q' + q1.id;
+                    q2.num = num++;
+                    formatted.push(q2);
+
+                    return;
+                }
+            } else if (q1.multiArray && q1.multiArray.length === 0) {
+                // It's a single question.
+                q1.name = 'q' + q1.id;
+                q1.num = num++;
+                if (q1.type > 0) { // Add "choose" option since this question is not required.
+                    q1.optionsArray.unshift(strChoose);
+                }
+            }
+
+            formatted.push(q1);
+        });
+
+        return formatted;
+    }
+
+}
+export const AddonModSurveyHelper = makeSingleton(AddonModSurveyHelperProvider);
+
+/**
+ * Survey question with some calculated data.
+ */
+export type AddonModSurveyQuestionFormatted = AddonModSurveyQuestion & {
+    required?: boolean; // Calculated in the app. Whether the question is required.
+    name?: string; // Calculated in the app. The name of the question.
+    num?: number; // Calculated in the app. Number of the question.
+    multiArray?: string[]; // Subquestions ids, converted to an array.
+    optionsArray?: string[]; // Question options, converted to an array.
+};

src/addons/mod/survey/services/survey-offline.ts

@@ -0,0 +1,151 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Injectable } from '@angular/core';
+import { CoreSites } from '@services/sites';
+import { CoreTextUtils } from '@services/utils/text';
+import { makeSingleton } from '@singletons';
+import { AddonModSurveyAnswersDBRecord, SURVEY_TABLE } from './database/survey';
+import { AddonModSurveySubmitAnswerData } from './survey';
+
+/**
+ * Service to handle Offline survey.
+ */
+@Injectable( { providedIn: 'root' })
+export class AddonModSurveyOfflineProvider {
+
+    /**
+     * Delete a survey answers.
+     *
+     * @param surveyId Survey ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @param userId User the answers belong to. If not defined, current user in site.
+     * @return Promise resolved if deleted, rejected if failure.
+     */
+    async deleteSurveyAnswers(surveyId: number, siteId?: string, userId?: number): Promise<void> {
+        const site = await CoreSites.getSite(siteId);
+        userId = userId || site.getUserId();
+
+        await site.getDb().deleteRecords(SURVEY_TABLE, { surveyid: surveyId, userid: userId });
+    }
+
+    /**
+     * Get all the stored data from all the surveys.
+     *
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved with answers.
+     */
+    async getAllData(siteId?: string): Promise<AddonModSurveyAnswersDBRecordFormatted[]> {
+        const site = await CoreSites.getSite(siteId);
+        const entries = await site.getDb().getAllRecords<AddonModSurveyAnswersDBRecord>(SURVEY_TABLE);
+
+        return entries.map((entry) => Object.assign(entry, {
+            answers: CoreTextUtils.parseJSON<AddonModSurveySubmitAnswerData[]>(entry.answers),
+        }));
+    }
+
+    /**
+     * Get a survey stored answers.
+     *
+     * @param surveyId Survey ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @param userId User the answers belong to. If not defined, current user in site.
+     * @return Promise resolved with the answers.
+     */
+    async getSurveyAnswers(surveyId: number, siteId?: string, userId?: number): Promise<AddonModSurveySubmitAnswerData[]> {
+        try {
+            const entry = await this.getSurveyData(surveyId, siteId, userId);
+
+            return entry.answers || [];
+        } catch {
+            return [];
+        }
+    }
+
+    /**
+     * Get a survey stored data.
+     *
+     * @param surveyId Survey ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @param userId User the answers belong to. If not defined, current user in site.
+     * @return Promise resolved with the data.
+     */
+    async getSurveyData(surveyId: number, siteId?: string, userId?: number): Promise<AddonModSurveyAnswersDBRecordFormatted> {
+        const site = await CoreSites.getSite(siteId);
+        userId = userId || site.getUserId();
+
+        const entry = await site.getDb().getRecord<AddonModSurveyAnswersDBRecord>(
+            SURVEY_TABLE,
+            { surveyid: surveyId, userid: userId },
+        );
+
+        return Object.assign(entry, {
+            answers: CoreTextUtils.parseJSON<AddonModSurveySubmitAnswerData[]>(entry.answers),
+        });
+    }
+
+    /**
+     * Check if there are offline answers to send.
+     *
+     * @param surveyId Survey ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @param userId User the answers belong to. If not defined, current user in site.
+     * @return Promise resolved with boolean: true if has offline answers, false otherwise.
+     */
+    async hasAnswers(surveyId: number, siteId?: string, userId?: number): Promise<boolean> {
+        const answers = await this.getSurveyAnswers(surveyId, siteId, userId);
+
+        return !!answers.length;
+    }
+
+    /**
+     * Save answers to be sent later.
+     *
+     * @param surveyId Survey ID.
+     * @param name Survey name.
+     * @param courseId Course ID the survey belongs to.
+     * @param answers Answers.
+     * @param siteId Site ID. If not defined, current site.
+     * @param userId User the answers belong to. If not defined, current user in site.
+     * @return Promise resolved if stored, rejected if failure.
+     */
+    async saveAnswers(
+        surveyId: number,
+        name: string,
+        courseId: number,
+        answers: AddonModSurveySubmitAnswerData[],
+        siteId?: string,
+        userId?: number,
+    ): Promise<void> {
+        const site = await CoreSites.getSite(siteId);
+        userId = userId || site.getUserId();
+
+        const entry: AddonModSurveyAnswersDBRecord = {
+            surveyid: surveyId,
+            name: name,
+            courseid: courseId,
+            userid: userId,
+            answers: JSON.stringify(answers),
+            timecreated: new Date().getTime(),
+        };
+
+        await site.getDb().insertRecord(SURVEY_TABLE, entry);
+    }
+
+}
+export const AddonModSurveyOffline = makeSingleton(AddonModSurveyOfflineProvider);
+
+export type AddonModSurveyAnswersDBRecordFormatted = Omit<AddonModSurveyAnswersDBRecord, 'answers'> & {
+    answers: AddonModSurveySubmitAnswerData[];
+};

src/addons/mod/survey/services/survey-sync.ts

@@ -0,0 +1,257 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Injectable } from '@angular/core';
+import { CoreNetworkError } from '@classes/errors/network-error';
+import { CoreCourseActivitySyncBaseProvider } from '@features/course/classes/activity-sync';
+import { CoreCourse } from '@features/course/services/course';
+import { CoreCourseLogHelper } from '@features/course/services/log-helper';
+import { CoreApp } from '@services/app';
+import { CoreSites } from '@services/sites';
+import { CoreTextUtils } from '@services/utils/text';
+import { CoreUtils } from '@services/utils/utils';
+import { makeSingleton, Translate } from '@singletons';
+import { CoreEvents } from '@singletons/events';
+import { AddonModSurveyPrefetchHandler } from './handlers/prefetch';
+import { AddonModSurvey, AddonModSurveyProvider } from './survey';
+import { AddonModSurveyAnswersDBRecordFormatted, AddonModSurveyOffline } from './survey-offline';
+
+/**
+ * Service to sync surveys.
+ */
+@Injectable( { providedIn: 'root' })
+export class AddonModSurveySyncProvider extends CoreCourseActivitySyncBaseProvider<AddonModSurveySyncResult> {
+
+    static readonly AUTO_SYNCED = 'addon_mod_survey_autom_synced';
+
+    protected componentTranslate: string;
+
+    constructor() {
+        super('AddonModSurveySyncProvider');
+        this.componentTranslate = CoreCourse.translateModuleName('survey');
+    }
+
+    /**
+     * Get the ID of a survey sync.
+     *
+     * @param surveyId Survey ID.
+     * @param userId User the answers belong to.
+     * @return Sync ID.
+     * @protected
+     */
+    getSyncId(surveyId: number, userId: number): string {
+        return surveyId + '#' + userId;
+    }
+
+    /**
+     * Try to synchronize all the surveys in a certain site or in all sites.
+     *
+     * @param siteId Site ID to sync. If not defined, sync all sites.
+     * @param force Wether to force sync not depending on last execution.
+     * @return Promise resolved if sync is successful, rejected if sync fails.
+     */
+    syncAllSurveys(siteId?: string, force?: boolean): Promise<void> {
+        return this.syncOnSites('all surveys', this.syncAllSurveysFunc.bind(this, !!force), siteId);
+    }
+
+    /**
+     * Sync all pending surveys on a site.
+     *
+     * @param force Wether to force sync not depending on last execution.
+     * @param siteId Site ID to sync.
+     * @param Promise resolved if sync is successful, rejected if sync fails.
+     */
+    protected async syncAllSurveysFunc(force: boolean, siteId: string): Promise<void> {
+        // Get all survey answers pending to be sent in the site.
+        const entries = await AddonModSurveyOffline.getAllData(siteId);
+
+        // Sync all surveys.
+        const promises = entries.map(async (entry) => {
+            const result = await (force
+                ? this.syncSurvey(entry.surveyid, entry.userid, siteId)
+                : this.syncSurveyIfNeeded(entry.surveyid, entry.userid, siteId));
+
+            if (result && result.answersSent) {
+                // Sync successful, send event.
+                CoreEvents.trigger(AddonModSurveySyncProvider.AUTO_SYNCED, {
+                    surveyId: entry.surveyid,
+                    userId: entry.userid,
+                    warnings: result.warnings,
+                }, siteId);
+            }
+        });
+
+        await Promise.all(promises);
+    }
+
+    /**
+     * Sync a survey only if a certain time has passed since the last time.
+     *
+     * @param surveyId Survey ID.
+     * @param userId User the answers belong to.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when the survey is synced or if it doesn't need to be synced.
+     */
+    async syncSurveyIfNeeded(surveyId: number, userId: number, siteId?: string): Promise<AddonModSurveySyncResult | undefined> {
+        const syncId = this.getSyncId(surveyId, userId);
+
+        const needed = await this.isSyncNeeded(syncId, siteId);
+        if (needed) {
+            return this.syncSurvey(surveyId, userId, siteId);
+        }
+    }
+
+    /**
+     * Synchronize a survey.
+     *
+     * @param surveyId Survey ID.
+     * @param userId User the answers belong to. If not defined, current user.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved if sync is successful, rejected otherwise.
+     */
+    async syncSurvey(surveyId: number, userId?: number, siteId?: string): Promise<AddonModSurveySyncResult> {
+        const site = await CoreSites.getSite(siteId);
+        siteId = site.getId();
+        userId = userId || site.getUserId();
+
+        const syncId = this.getSyncId(surveyId, userId);
+
+        if (this.isSyncing(syncId, siteId)) {
+            // There's already a sync ongoing for this site, return the promise.
+            return this.getOngoingSync(syncId, siteId)!;
+        }
+
+        this.logger.debug(`Try to sync survey '${surveyId}' for user '${userId}'`);
+
+        // Get offline events.
+        const syncPromise = this.performSyncSurvey(surveyId, userId, siteId);
+
+        return this.addOngoingSync(syncId, syncPromise, siteId);
+    }
+
+    /**
+     * Perform the survey sync.
+     *
+     * @param surveyId Survey ID.
+     * @param userId User the answers belong to. If not defined, current user.
+     * @param siteId Site ID.
+     * @return Promise resolved if sync is successful, rejected otherwise.
+     */
+    protected async performSyncSurvey(surveyId: number, userId: number, siteId: string): Promise<AddonModSurveySyncResult> {
+        const result: AddonModSurveySyncResult = {
+            warnings: [],
+            answersSent: false,
+        };
+
+        // Sync offline logs.
+        CoreUtils.ignoreErrors(CoreCourseLogHelper.syncActivity(AddonModSurveyProvider.COMPONENT, surveyId, siteId));
+
+        let answersNumber = 0;
+        let data: AddonModSurveyAnswersDBRecordFormatted | undefined;
+        try {
+            // Get answers to be sent.
+            data = await AddonModSurveyOffline.getSurveyData(surveyId, siteId, userId);
+
+            answersNumber = data.answers.length;
+        } catch {
+            // Ignore errors.
+        }
+
+        if (answersNumber > 0 && data) {
+            if (!CoreApp.isOnline()) {
+                // Cannot sync in offline.
+                throw new CoreNetworkError();
+            }
+
+            result.courseId = data.courseid;
+
+            // Send the answers.
+            try {
+                await AddonModSurvey.submitAnswersOnline(surveyId, data.answers, siteId);
+
+                result.answersSent = true;
+
+                // Answers sent, delete them.
+                await AddonModSurveyOffline.deleteSurveyAnswers(surveyId, siteId, userId);
+            } catch (error) {
+                if (!CoreUtils.isWebServiceError(error)) {
+                    // Local error, reject.
+                    throw error;
+                }
+
+                // The WebService has thrown an error, this means that answers cannot be submitted. Delete them.
+                result.answersSent = true;
+
+                await AddonModSurveyOffline.deleteSurveyAnswers(surveyId, siteId, userId);
+
+                // Answers deleted, add a warning.
+                result.warnings.push(Translate.instant('core.warningofflinedatadeleted', {
+                    component: this.componentTranslate,
+                    name: data.name,
+                    error: CoreTextUtils.getErrorMessageFromError(error),
+                }));
+            }
+
+            if (result.courseId) {
+                await AddonModSurvey.invalidateSurveyData(result.courseId, siteId);
+
+                // Data has been sent to server, update survey data.
+                const module = await CoreCourse.getModuleBasicInfoByInstance(surveyId, 'survey', siteId);
+
+                CoreUtils.ignoreErrors(
+                    this.prefetchAfterUpdate(AddonModSurveyPrefetchHandler.instance, module, result.courseId, undefined, siteId),
+                );
+            }
+        }
+
+        const syncId = this.getSyncId(surveyId, userId);
+        // Sync finished, set sync time.
+        CoreUtils.ignoreErrors(this.setSyncTime(syncId, siteId));
+
+        return result;
+    }
+
+}
+export const AddonModSurveySync = makeSingleton(AddonModSurveySyncProvider);
+
+declare module '@singletons/events' {
+
+    /**
+     * Augment CoreEventsData interface with events specific to this service.
+     *
+     * @see https://www.typescriptlang.org/docs/handbook/declaration-merging.html#module-augmentation
+     */
+    export interface CoreEventsData {
+        [AddonModSurveySyncProvider.AUTO_SYNCED]: AddonModSurveyAutoSyncData;
+    }
+
+}
+
+/**
+ * Data returned by a assign sync.
+ */
+export type AddonModSurveySyncResult = {
+    warnings: string[]; // List of warnings.
+    answersSent: boolean; // Whether some data was sent to the server or offline data was updated.
+    courseId?: number; // Course the survey belongs to (if known).
+};
+
+/**
+ * Data passed to AUTO_SYNCED event.
+ */
+export type AddonModSurveyAutoSyncData = {
+    surveyId: number;
+    warnings: string[];
+    userId: number;
+};

src/addons/mod/survey/services/survey.ts

@@ -0,0 +1,393 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { Injectable } from '@angular/core';
+import { CoreError } from '@classes/errors/error';
+import { CoreSite, CoreSiteWSPreSets } from '@classes/site';
+import { CoreCourseCommonModWSOptions } from '@features/course/services/course';
+import { CoreCourseLogHelper } from '@features/course/services/log-helper';
+import { CoreApp } from '@services/app';
+import { CoreFilepool } from '@services/filepool';
+import { CoreSites, CoreSitesCommonWSOptions } from '@services/sites';
+import { CoreUtils } from '@services/utils/utils';
+import { CoreStatusWithWarningsWSResponse, CoreWSExternalFile, CoreWSExternalWarning } from '@services/ws';
+import { makeSingleton } from '@singletons';
+import { AddonModSurveyOffline } from './survey-offline';
+
+const ROOT_CACHE_KEY = 'mmaModSurvey:';
+
+/**
+ * Service that provides some features for surveys.
+ */
+@Injectable( { providedIn: 'root' })
+export class AddonModSurveyProvider {
+
+    static readonly COMPONENT = 'mmaModSurvey';
+
+    /**
+     * Get a survey's questions.
+     *
+     * @param surveyId Survey ID.
+     * @param options Other options.
+     * @return Promise resolved when the questions are retrieved.
+     */
+    async getQuestions(surveyId: number, options: CoreCourseCommonModWSOptions = {}): Promise<AddonModSurveyQuestion[]> {
+        const site = await CoreSites.getSite(options.siteId);
+
+        const params: AddonModSurveyGetQuestionsWSParams = {
+            surveyid: surveyId,
+        };
+
+        const preSets: CoreSiteWSPreSets = {
+            cacheKey: this.getQuestionsCacheKey(surveyId),
+            updateFrequency: CoreSite.FREQUENCY_RARELY,
+            component: AddonModSurveyProvider.COMPONENT,
+            componentId: options.cmId,
+            ...CoreSites.getReadingStrategyPreSets(options.readingStrategy), // Include reading strategy preSets.
+        };
+
+        const response = await site.read<AddonModSurveyGetQuestionsWSResponse>('mod_survey_get_questions', params, preSets);
+        if (response.questions) {
+            return response.questions;
+        }
+
+        throw new CoreError('No questions were found.');
+    }
+
+    /**
+     * Get cache key for survey questions WS calls.
+     *
+     * @param surveyId Survey ID.
+     * @return Cache key.
+     */
+    protected getQuestionsCacheKey(surveyId: number): string {
+        return ROOT_CACHE_KEY + 'questions:' + surveyId;
+    }
+
+    /**
+     * Get cache key for survey data WS calls.
+     *
+     * @param courseId Course ID.
+     * @return Cache key.
+     */
+    protected getSurveyCacheKey(courseId: number): string {
+        return ROOT_CACHE_KEY + 'survey:' + courseId;
+    }
+
+    /**
+     * Get a survey data.
+     *
+     * @param courseId Course ID.
+     * @param key Name of the property to check.
+     * @param value Value to search.
+     * @param options Other options.
+     * @return Promise resolved when the survey is retrieved.
+     */
+    protected async getSurveyDataByKey(
+        courseId: number,
+        key: string,
+        value: number,
+        options: CoreSitesCommonWSOptions = {},
+    ): Promise<AddonModSurveySurvey> {
+        const site = await CoreSites.getSite(options.siteId);
+
+        const params: AddonModSurveyGetSurveysByCoursesWSParams = {
+            courseids: [courseId],
+        };
+
+        const preSets: CoreSiteWSPreSets = {
+            cacheKey: this.getSurveyCacheKey(courseId),
+            updateFrequency: CoreSite.FREQUENCY_RARELY,
+            component: AddonModSurveyProvider.COMPONENT,
+            ...CoreSites.getReadingStrategyPreSets(options.readingStrategy), // Include reading strategy preSets.
+        };
+
+        const response =
+            await site.read<AddonModSurveyGetSurveysByCoursesWSResponse>('mod_survey_get_surveys_by_courses', params, preSets);
+
+        const currentSurvey = response.surveys.find((survey) => survey[key] == value);
+        if (currentSurvey) {
+            return currentSurvey;
+        }
+
+        throw new CoreError('Activity not found.');
+    }
+
+    /**
+     * Get a survey by course module ID.
+     *
+     * @param courseId Course ID.
+     * @param cmId Course module ID.
+     * @param options Other options.
+     * @return Promise resolved when the survey is retrieved.
+     */
+    getSurvey(courseId: number, cmId: number, options: CoreSitesCommonWSOptions = {}): Promise<AddonModSurveySurvey> {
+        return this.getSurveyDataByKey(courseId, 'coursemodule', cmId, options);
+    }
+
+    /**
+     * Get a survey by ID.
+     *
+     * @param courseId Course ID.
+     * @param id Survey ID.
+     * @param options Other options.
+     * @return Promise resolved when the survey is retrieved.
+     */
+    getSurveyById(courseId: number, id: number, options: CoreSitesCommonWSOptions = {}): Promise<AddonModSurveySurvey> {
+        return this.getSurveyDataByKey(courseId, 'id', id, options);
+    }
+
+    /**
+     * Invalidate the prefetched content.
+     *
+     * @param moduleId The module ID.
+     * @param courseId Course ID of the module.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when the data is invalidated.
+     */
+    async invalidateContent(moduleId: number, courseId: number, siteId?: string): Promise<void> {
+        siteId = siteId || CoreSites.getCurrentSiteId();
+
+        const promises: Promise<void>[] = [];
+
+        promises.push(this.getSurvey(courseId, moduleId).then(async (survey) => {
+            const ps: Promise<void>[] = [];
+
+            // Do not invalidate activity data before getting activity info, we need it!
+            ps.push(this.invalidateSurveyData(courseId, siteId));
+            ps.push(this.invalidateQuestions(survey.id, siteId));
+
+            await Promise.all(ps);
+
+            return;
+        }));
+
+        promises.push(CoreFilepool.invalidateFilesByComponent(siteId, AddonModSurveyProvider.COMPONENT, moduleId));
+
+        await CoreUtils.allPromises(promises);
+    }
+
+    /**
+     * Invalidates survey questions.
+     *
+     * @param surveyId Survey ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when the data is invalidated.
+     */
+    async invalidateQuestions(surveyId: number, siteId?: string): Promise<void> {
+        const site = await CoreSites.getSite(siteId);
+
+        await site.invalidateWsCacheForKey(this.getQuestionsCacheKey(surveyId));
+    }
+
+    /**
+     * Invalidates survey data.
+     *
+     * @param courseId Course ID.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when the data is invalidated.
+     */
+    async invalidateSurveyData(courseId: number, siteId?: string): Promise<void> {
+        const site = await CoreSites.getSite(siteId);
+
+        await site.invalidateWsCacheForKey(this.getSurveyCacheKey(courseId));
+    }
+
+    /**
+     * Report the survey as being viewed.
+     *
+     * @param id Module ID.
+     * @param name Name of the assign.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when the WS call is successful.
+     */
+    async logView(id: number, name?: string, siteId?: string): Promise<void> {
+        const params: AddonModSurveyViewSurveyWSParams = {
+            surveyid: id,
+        };
+
+        await CoreCourseLogHelper.logSingle(
+            'mod_survey_view_survey',
+            params,
+            AddonModSurveyProvider.COMPONENT,
+            id,
+            name,
+            'survey',
+            {},
+            siteId,
+        );
+    }
+
+    /**
+     * Send survey answers. If cannot send them to Moodle, they'll be stored in offline to be sent later.
+     *
+     * @param surveyId Survey ID.
+     * @param name Survey name.
+     * @param courseId Course ID the survey belongs to.
+     * @param answers Answers.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved with boolean if success: true if answers were sent to server,
+     *         false if stored in device.
+     */
+    async submitAnswers(
+        surveyId: number,
+        name: string,
+        courseId: number,
+        answers: AddonModSurveySubmitAnswerData[],
+        siteId?: string,
+    ): Promise<boolean> {
+
+        // Convenience function to store a survey to be synchronized later.
+        const storeOffline = async (): Promise<boolean> => {
+            await AddonModSurveyOffline.saveAnswers(surveyId, name, courseId, answers, siteId);
+
+            return false;
+        };
+
+        siteId = siteId || CoreSites.getCurrentSiteId();
+
+        if (!CoreApp.isOnline()) {
+            // App is offline, store the message.
+            return storeOffline();
+        }
+
+        try {
+            // If there's already answers to be sent to the server, discard it first.
+            await AddonModSurveyOffline.deleteSurveyAnswers(surveyId, siteId);
+
+            // Device is online, try to send them to server.
+            await this.submitAnswersOnline(surveyId, answers, siteId);
+
+            return true;
+        } catch (error) {
+            if (CoreUtils.isWebServiceError(error)) {
+                // It's a WebService error, the user cannot send the message so don't store it.
+                throw error;
+            }
+
+            return storeOffline();
+        }
+    }
+
+    /**
+     * Send survey answers to Moodle.
+     *
+     * @param surveyId Survey ID.
+     * @param answers Answers.
+     * @param siteId Site ID. If not defined, current site.
+     * @return Promise resolved when answers are successfully submitted.
+     */
+    async submitAnswersOnline(surveyId: number, answers: AddonModSurveySubmitAnswerData[], siteId?: string): Promise<void> {
+        const site = await CoreSites.getSite(siteId);
+
+        const params: AddonModSurveySubmitAnswersWSParams = {
+            surveyid: surveyId,
+            answers: answers,
+        };
+
+        const response = await site.write<CoreStatusWithWarningsWSResponse>('mod_survey_submit_answers', params);
+        if (!response.status) {
+            throw new CoreError('Error submitting answers.');
+        }
+    }
+
+}
+export const AddonModSurvey = makeSingleton(AddonModSurveyProvider);
+
+/**
+ * Params of mod_survey_view_survey WS.
+ */
+type AddonModSurveyViewSurveyWSParams = {
+    surveyid: number; // Survey instance id.
+};
+
+/**
+ * Survey returned by WS mod_survey_get_surveys_by_courses.
+ */
+export type AddonModSurveySurvey = {
+    id: number; // Survey id.
+    coursemodule: number; // Course module id.
+    course: number; // Course id.
+    name: string; // Survey name.
+    intro?: string; // The Survey intro.
+    introformat?: number; // Intro format (1 = HTML, 0 = MOODLE, 2 = PLAIN or 4 = MARKDOWN).
+    introfiles?: CoreWSExternalFile[]; // @since 3.2.
+    template?: number; // Survey type.
+    days?: number; // Days.
+    questions?: string; // Question ids.
+    surveydone?: number; // Did I finish the survey?.
+    timecreated?: number; // Time of creation.
+    timemodified?: number; // Time of last modification.
+    section?: number; // Course section id.
+    visible?: number; // Visible.
+    groupmode?: number; // Group mode.
+    groupingid?: number; // Group id.
+};
+
+/**
+ * Survey question.
+ */
+export type AddonModSurveyQuestion = {
+    id: number; // Question id.
+    text: string; // Question text.
+    shorttext: string; // Question short text.
+    multi: string; // Subquestions ids.
+    intro: string; // The question intro.
+    type: number; // Question type.
+    options: string; // Question options.
+    parent: number; // Parent question (for subquestions).
+};
+
+/**
+ * Params of mod_survey_get_questions WS.
+ */
+type AddonModSurveyGetQuestionsWSParams = {
+    surveyid: number; // Survey instance id.
+};
+
+/**
+ * Data returned by mod_survey_get_questions WS.
+ */
+export type AddonModSurveyGetQuestionsWSResponse = {
+    questions: AddonModSurveyQuestion[];
+    warnings?: CoreWSExternalWarning[];
+};
+
+/**
+ * Params of mod_survey_get_surveys_by_courses WS.
+ */
+type AddonModSurveyGetSurveysByCoursesWSParams = {
+    courseids?: number[]; // Array of course ids.
+};
+
+/**
+ * Data returned by mod_survey_get_surveys_by_courses WS.
+ */
+export type AddonModSurveyGetSurveysByCoursesWSResponse = {
+    surveys: AddonModSurveySurvey[];
+    warnings?: CoreWSExternalWarning[];
+};
+
+export type AddonModSurveySubmitAnswerData = {
+    key: string; // Answer key.
+    value: string; // Answer value.
+};
+
+/**
+ * Params of mod_survey_submit_answers WS.
+ */
+type AddonModSurveySubmitAnswersWSParams = {
+    surveyid: number; // Survey id.
+    answers: AddonModSurveySubmitAnswerData[];
+};

src/addons/mod/survey/survey-lazy.module.ts

@@ -0,0 +1,39 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { NgModule } from '@angular/core';
+import { RouterModule, Routes } from '@angular/router';
+
+import { CoreSharedModule } from '@/core/shared.module';
+import { AddonModSurveyIndexPage } from './pages/index';
+import { AddonModSurveyComponentsModule } from './components/components.module';
+
+const routes: Routes = [
+    {
+        path: ':courseId/:cmId',
+        component: AddonModSurveyIndexPage,
+    },
+];
+
+@NgModule({
+    imports: [
+        RouterModule.forChild(routes),
+        CoreSharedModule,
+        AddonModSurveyComponentsModule,
+    ],
+    declarations: [
+        AddonModSurveyIndexPage,
+    ],
+})
+export class AddonModSurveyLazyModule {}

src/addons/mod/survey/survey.module.ts

@@ -0,0 +1,75 @@
+// (C) Copyright 2015 Moodle Pty Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import { APP_INITIALIZER, NgModule, Type } from '@angular/core';
+import { Routes } from '@angular/router';
+import { CoreContentLinksDelegate } from '@features/contentlinks/services/contentlinks-delegate';
+import { CoreCourseModuleDelegate } from '@features/course/services/module-delegate';
+import { CoreCourseModulePrefetchDelegate } from '@features/course/services/module-prefetch-delegate';
+import { CoreMainMenuTabRoutingModule } from '@features/mainmenu/mainmenu-tab-routing.module';
+import { CoreCronDelegate } from '@services/cron';
+import { CORE_SITE_SCHEMAS } from '@services/sites';
+import { AddonModSurveyComponentsModule } from './components/components.module';
+import { ADDON_MOD_SURVEY_OFFLINE_SITE_SCHEMA } from './services/database/survey';
+import { AddonModSurveyIndexLinkHandler } from './services/handlers/index-link';
+import { AddonModSurveyListLinkHandler } from './services/handlers/list-link';
+import { AddonModSurveyModuleHandler, AddonModSurveyModuleHandlerService } from './services/handlers/module';
+import { AddonModSurveyPrefetchHandler } from './services/handlers/prefetch';
+import { AddonModSurveySyncCronHandler } from './services/handlers/sync-cron';
+import { AddonModSurveyProvider } from './services/survey';
+import { AddonModSurveyHelperProvider } from './services/survey-helper';
+import { AddonModSurveyOfflineProvider } from './services/survey-offline';
+import { AddonModSurveySyncProvider } from './services/survey-sync';
+
+// List of providers (without handlers).
+export const ADDON_MOD_SURVEY_SERVICES: Type<unknown>[] = [
+    AddonModSurveyProvider,
+    AddonModSurveyHelperProvider,
+    AddonModSurveySyncProvider,
+    AddonModSurveyOfflineProvider,
+];
+
+const routes: Routes = [
+    {
+        path: AddonModSurveyModuleHandlerService.PAGE_NAME,
+        loadChildren: () => import('./survey-lazy.module').then(m => m.AddonModSurveyLazyModule),
+    },
+];
+
+@NgModule({
+    imports: [
+        CoreMainMenuTabRoutingModule.forChild(routes),
+        AddonModSurveyComponentsModule,
+    ],
+    providers: [
+        {
+            provide: CORE_SITE_SCHEMAS,
+            useValue: [ADDON_MOD_SURVEY_OFFLINE_SITE_SCHEMA],
+            multi: true,
+        },
+        {
+            provide: APP_INITIALIZER,
+            multi: true,
+            deps: [],
+            useFactory: () => () => {
+                CoreCourseModuleDelegate.registerHandler(AddonModSurveyModuleHandler.instance);
+                CoreCourseModulePrefetchDelegate.registerHandler(AddonModSurveyPrefetchHandler.instance);
+                CoreCronDelegate.register(AddonModSurveySyncCronHandler.instance);
+                CoreContentLinksDelegate.registerHandler(AddonModSurveyIndexLinkHandler.instance);
+                CoreContentLinksDelegate.registerHandler(AddonModSurveyListLinkHandler.instance);
+            },
+        },
+    ],
+})
+export class AddonModSurveyModule {}

src/core/features/compile/services/compile.ts

@@ -137,7 +137,7 @@ import { ADDON_MOD_PAGE_SERVICES } from '@addons/mod/page/page.module';
 import { ADDON_MOD_QUIZ_SERVICES } from '@addons/mod/quiz/quiz.module';
 import { ADDON_MOD_RESOURCE_SERVICES } from '@addons/mod/resource/resource.module';
 // @todo import { ADDON_MOD_SCORM_SERVICES } from '@addons/mod/scorm/scorm.module';
-// @todo import { ADDON_MOD_SURVEY_SERVICES } from '@addons/mod/survey/survey.module';
+import { ADDON_MOD_SURVEY_SERVICES } from '@addons/mod/survey/survey.module';
 import { ADDON_MOD_URL_SERVICES } from '@addons/mod/url/url.module';
 // @todo import { ADDON_MOD_WIKI_SERVICES } from '@addons/mod/wiki/wiki.module';
 // @todo import { ADDON_MOD_WORKSHOP_SERVICES } from '@addons/mod/workshop/workshop.module';
@@ -302,7 +302,7 @@ export class CoreCompileProvider {
             ...ADDON_MOD_QUIZ_SERVICES,
             ...ADDON_MOD_RESOURCE_SERVICES,
             // @todo ...ADDON_MOD_SCORM_SERVICES,
-            // @todo ...ADDON_MOD_SURVEY_SERVICES,
+            ...ADDON_MOD_SURVEY_SERVICES,
             ...ADDON_MOD_URL_SERVICES,
             // @todo ...ADDON_MOD_WIKI_SERVICES,
             // @todo ...ADDON_MOD_WORKSHOP_SERVICES,