MOBILE-2348 quiz: Implement access rules delegate

src/addon/mod/quiz/providers/access-rules-delegate.ts

@@ -0,0 +1,273 @@
+// (C) Copyright 2015 Martin Dougiamas
+//
+// 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, Injector } from '@angular/core';
+import { CoreLoggerProvider } from '@providers/logger';
+import { CoreEventsProvider } from '@providers/events';
+import { CoreSitesProvider } from '@providers/sites';
+import { CoreUtilsProvider } from '@providers/utils/utils';
+import { CoreDelegate, CoreDelegateHandler } from '@classes/delegate';
+
+/**
+ * Interface that all access rules handlers must implement.
+ */
+export interface AddonModQuizAccessRuleHandler extends CoreDelegateHandler {
+
+    /**
+     * Name of the rule the handler supports. E.g. 'password'.
+     * @type {string}
+     */
+    ruleName: string;
+
+    /**
+     * Whether the rule requires a preflight check when prefetch/start/continue an attempt.
+     *
+     * @param {any} quiz The quiz the rule belongs to.
+     * @param {any} attempt The attempt started/continued.
+     * @param {boolean} [prefetch] Whether the user is prefetching the quiz.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {boolean|Promise<boolean>} Whether the rule requires a preflight check.
+     */
+    isPreflightCheckRequired(quiz: any, attempt: any, prefetch?: boolean, siteId?: string): boolean | Promise<boolean>;
+
+    /**
+     * Add preflight data that doesn't require user interaction. The data should be added to the preflightData param.
+     *
+     * @param {any} quiz The quiz the rule belongs to.
+     * @param {any} attempt The attempt started/continued.
+     * @param {any} preflightData Object where to add the preflight data.
+     * @param {boolean} [prefetch] Whether the user is prefetching the quiz.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {void|Promise<any>} Promise resolved when done if async, void if it's synchronous.
+     */
+    getFixedPreflightData?(quiz: any, attempt: any, preflightData: any, prefetch?: boolean, siteId?: string): void | Promise<any>;
+
+    /**
+     * Return the Component to use to display the access rule preflight.
+     * Implement this if your access rule requires a preflight check with user interaction.
+     * It's recommended to return the class of the component, but you can also return an instance of the component.
+     *
+     * @param {Injector} injector Injector.
+     * @return {any|Promise<any>} The component (or promise resolved with component) to use, undefined if not found.
+     */
+    getPreflightComponent?(injector: Injector): any | Promise<any>;
+
+    /**
+     * Function called when the preflight check has passed. This is a chance to record that fact in some way.
+     *
+     * @param {any} quiz The quiz the rule belongs to.
+     * @param {any} attempt The attempt started/continued.
+     * @param {any} preflightData Preflight data gathered.
+     * @param {boolean} [prefetch] Whether the user is prefetching the quiz.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {void|Promise<any>} Promise resolved when done if async, void if it's synchronous.
+     */
+    notifyPreflightCheckPassed?(quiz: any, attempt: any, preflightData: any, prefetch?: boolean, siteId?: string)
+        : void | Promise<any>;
+
+    /**
+     * Function called when the preflight check fails. This is a chance to record that fact in some way.
+     *
+     * @param {any} quiz The quiz the rule belongs to.
+     * @param {any} attempt The attempt started/continued.
+     * @param {any} preflightData Preflight data gathered.
+     * @param {boolean} [prefetch] Whether the user is prefetching the quiz.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {void|Promise<any>} Promise resolved when done if async, void if it's synchronous.
+     */
+    notifyPreflightCheckFailed?(quiz: any, attempt: any, preflightData: any, prefetch?: boolean, siteId?: string)
+        : void | Promise<any>;
+
+    /**
+     * Whether or not the time left of an attempt should be displayed.
+     *
+     * @param {any} attempt The attempt.
+     * @param {number} endTime The attempt end time (in seconds).
+     * @param {number} timeNow The current time in seconds.
+     * @return {boolean} Whether it should be displayed.
+     */
+    shouldShowTimeLeft?(attempt: any, endTime: number, timeNow: number): boolean;
+}
+
+/**
+ * Delegate to register access rules for quiz module.
+ */
+@Injectable()
+export class AddonModQuizAccessRuleDelegate extends CoreDelegate {
+
+    protected handlerNameProperty = 'ruleName';
+
+    constructor(logger: CoreLoggerProvider, sitesProvider: CoreSitesProvider, eventsProvider: CoreEventsProvider,
+            protected utils: CoreUtilsProvider) {
+        super('AddonModQuizAccessRulesDelegate', logger, sitesProvider, eventsProvider);
+    }
+
+    /**
+     * Get the handler for a certain rule.
+     *
+     * @param {string} ruleName Name of the access rule.
+     * @return {AddonModQuizAccessRuleHandler} Handler. Undefined if no handler found for the rule.
+     */
+    getAccessRuleHandler(ruleName: string): AddonModQuizAccessRuleHandler {
+        return <AddonModQuizAccessRuleHandler> this.getHandler(ruleName, true);
+    }
+
+    /**
+     * Given a list of rules, get some fixed preflight data (data that doesn't require user interaction).
+     *
+     * @param {string[]} rules List of active rules names.
+     * @param {any} quiz Quiz.
+     * @param {any} attempt Attempt.
+     * @param {any} preflightData Object where to store the preflight data.
+     * @param {boolean} [prefetch] Whether the user is prefetching the quiz.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {Promise<any>} Promise resolved when all the data has been gathered.
+     */
+    getFixedPreflightData(rules: string[], quiz: any, attempt: any, preflightData: any, prefetch?: boolean, siteId?: string)
+            : Promise<any> {
+        rules = rules || [];
+
+        const promises = [];
+        rules.forEach((rule) => {
+            promises.push(Promise.resolve(
+                this.executeFunctionOnEnabled(rule, 'getFixedPreflightData', [quiz, attempt, preflightData, prefetch, siteId])
+            ));
+        });
+
+        return this.utils.allPromises(promises).catch(() => {
+            // Never reject.
+        });
+    }
+
+    /**
+     * Check if an access rule is supported.
+     *
+     * @param {string} ruleName Name of the rule.
+     * @return {boolean} Whether it's supported.
+     */
+    isAccessRuleSupported(ruleName: string): boolean {
+        return this.hasHandler(ruleName, true);
+    }
+
+    /**
+     * Given a list of rules, check if preflight check is required.
+     *
+     * @param {string[]} rules List of active rules names.
+     * @param {any} quiz Quiz.
+     * @param {any} attempt Attempt.
+     * @param {boolean} [prefetch] Whether the user is prefetching the quiz.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {Promise<boolean>} Promise resolved with boolean: whether it's required.
+     */
+    isPreflightCheckRequired(rules: string[], quiz: any, attempt: any, prefetch?: boolean, siteId?: string): Promise<boolean> {
+        rules = rules || [];
+
+        const promises = [];
+        let isRequired = false;
+
+        rules.forEach((rule) => {
+            promises.push(Promise.resolve(
+                this.executeFunctionOnEnabled(rule, 'isPreflightCheckRequired', [quiz, attempt, prefetch, siteId])
+            ).then((required) => {
+                if (required) {
+                    isRequired = true;
+                }
+            }));
+        });
+
+        return this.utils.allPromises(promises).then(() => {
+            return isRequired;
+        }).catch(() => {
+            // Never reject.
+            return isRequired;
+        });
+    }
+
+    /**
+     * Notify all rules that the preflight check has passed.
+     *
+     * @param {string[]} rules List of active rules names.
+     * @param {any} quiz Quiz.
+     * @param {any} attempt Attempt.
+     * @param {any} preflightData Preflight data gathered.
+     * @param {boolean} [prefetch] Whether the user is prefetching the quiz.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {Promise<any>} Promise resolved when done.
+     */
+    notifyPreflightCheckPassed(rules: string[], quiz: any, attempt: any, preflightData: any, prefetch?: boolean, siteId?: string)
+            : Promise<any> {
+        rules = rules || [];
+
+        const promises = [];
+        rules.forEach((rule) => {
+            promises.push(Promise.resolve(
+                this.executeFunctionOnEnabled(rule, 'notifyPreflightCheckPassed', [quiz, attempt, preflightData, prefetch, siteId])
+            ));
+        });
+
+        return this.utils.allPromises(promises).catch(() => {
+            // Never reject.
+        });
+    }
+
+    /**
+     * Notify all rules that the preflight check has failed.
+     *
+     * @param {string[]} rules List of active rules names.
+     * @param {any} quiz Quiz.
+     * @param {any} attempt Attempt.
+     * @param {any} preflightData Preflight data gathered.
+     * @param {boolean} [prefetch] Whether the user is prefetching the quiz.
+     * @param {string} [siteId] Site ID. If not defined, current site.
+     * @return {Promise<any>} Promise resolved when done.
+     */
+    notifyPreflightCheckFailed(rules: string[], quiz: any, attempt: any, preflightData: any, prefetch?: boolean, siteId?: string)
+            : Promise<any> {
+        rules = rules || [];
+
+        const promises = [];
+        rules.forEach((rule) => {
+            promises.push(Promise.resolve(
+                this.executeFunctionOnEnabled(rule, 'notifyPreflightCheckFailed', [quiz, attempt, preflightData, prefetch, siteId])
+            ));
+        });
+
+        return this.utils.allPromises(promises).catch(() => {
+            // Never reject.
+        });
+    }
+
+    /**
+     * Whether or not the time left of an attempt should be displayed.
+     *
+     * @param {string[]} rules List of active rules names.
+     * @param {any} attempt The attempt.
+     * @param {number} endTime The attempt end time (in seconds).
+     * @param {number} timeNow The current time in seconds.
+     * @return {boolean} Whether it should be displayed.
+     */
+    shouldShowTimeLeft(rules: string[], attempt: any, endTime: number, timeNow: number): boolean {
+        rules = rules || [];
+
+        for (const i in rules) {
+            const rule = rules[i];
+
+            if (this.executeFunctionOnEnabled(rule, 'shouldShowTimeLeft', [attempt, endTime, timeNow])) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+}

src/addon/mod/quiz/quiz.module.ts

@@ -0,0 +1,27 @@
+// (C) Copyright 2015 Martin Dougiamas
+//
+// 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 { AddonModQuizAccessRuleDelegate } from './providers/access-rules-delegate';
+
+@NgModule({
+    declarations: [
+    ],
+    imports: [
+    ],
+    providers: [
+        AddonModQuizAccessRuleDelegate
+    ]
+})
+export class AddonModQuizModule { }

src/app/app.module.ts

@@ -80,6 +80,7 @@ import { AddonModLabelModule } from '@addon/mod/label/label.module';
 import { AddonModResourceModule } from '@addon/mod/resource/resource.module';
 import { AddonModFolderModule } from '@addon/mod/folder/folder.module';
 import { AddonModPageModule } from '@addon/mod/page/page.module';
+import { AddonModQuizModule } from '@addon/mod/quiz/quiz.module';
 import { AddonModUrlModule } from '@addon/mod/url/url.module';
 import { AddonModSurveyModule } from '@addon/mod/survey/survey.module';
 import { AddonMessagesModule } from '@addon/messages/messages.module';
@@ -169,6 +170,7 @@ export const CORE_PROVIDERS: any[] = [
         AddonModResourceModule,
         AddonModFolderModule,
         AddonModPageModule,
+        AddonModQuizModule,
         AddonModUrlModule,
         AddonModSurveyModule,
         AddonMessagesModule,

src/classes/delegate.ts

@@ -83,6 +83,12 @@ export class CoreDelegate {
      */
     protected handlerNameProperty = 'name';
 
+    /**
+     * Set of promises to update a handler, to prevent doing the same operation twice.
+     * @type {{[siteId: string]: {[name: string]: Promise<any>}}}
+     */
+    protected updatePromises: {[siteId: string]: {[name: string]: Promise<any>}} = {};
+
     /**
      * Constructor of the Delegate.
      *
@@ -215,6 +221,13 @@ export class CoreDelegate {
             currentSite = this.sitesProvider.getCurrentSite();
         let promise;
 
+        if (this.updatePromises[siteId] && this.updatePromises[siteId][handler.name]) {
+            // There's already an update ongoing for this handler, return the promise.
+            return this.updatePromises[siteId][handler.name];
+        } else if (!this.updatePromises[siteId]) {
+            this.updatePromises[siteId] = {};
+        }
+
         if (!this.sitesProvider.isLoggedIn()) {
             promise = Promise.reject(null);
         } else if (this.isFeatureDisabled(handler, currentSite)) {
@@ -224,7 +237,7 @@ export class CoreDelegate {
         }
 
         // Checks if the handler is enabled.
-        return promise.catch(() => {
+        this.updatePromises[siteId][handler.name] = promise.catch(() => {
             return false;
         }).then((enabled: boolean) => {
             // Verify that this call is the last one that was started.
@@ -236,7 +249,12 @@ export class CoreDelegate {
                     delete this.enabledHandlers[handler[this.handlerNameProperty]];
                 }
             }
+        }).finally(() => {
+            // Update finished, delete the promise.
+            delete this.updatePromises[siteId][handler.name];
         });
+
+        return this.updatePromises[siteId][handler.name];
     }
 
     /**