MOBILE-4138 core: Wait for ready on delegates

src/core/classes/delegate-sorted.ts

@@ -16,7 +16,6 @@ import { BehaviorSubject, Subject } from 'rxjs';
 import { CoreEvents } from '@singletons/events';
 import { CoreDelegate, CoreDelegateDisplayHandler, CoreDelegateToDisplay } from './delegate';
 import { CoreSites } from '@services/sites';
-import { CorePromisedValue } from '@classes/promised-value';
 
 /**
  * Superclass to help creating sorted delegates.
@@ -26,7 +25,6 @@ export class CoreSortedDelegate<
     HandlerType extends CoreDelegateDisplayHandler<DisplayType>>
     extends CoreDelegate<HandlerType> {
 
-    protected loaded = false;
     protected sortedHandlersRxJs: Subject<DisplayType[]> = new BehaviorSubject<DisplayType[]>([]);
     protected sortedHandlers: DisplayType[] = [];
 
@@ -53,14 +51,14 @@ export class CoreSortedDelegate<
      * @returns True if handlers are loaded, false otherwise.
      */
     areHandlersLoaded(): boolean {
-        return this.loaded;
+        return this.handlersLoaded;
     }
 
     /**
      * Clear current site handlers. Reserved for core use.
      */
     protected clearSortedHandlers(): void {
-        this.loaded = false;
+        this.handlersLoaded = false;
         this.sortedHandlersRxJs.next([]);
         this.sortedHandlers = [];
     }
@@ -74,6 +72,13 @@ export class CoreSortedDelegate<
         return this.sortedHandlers;
     }
 
+    /**
+     * @inheritdoc
+     */
+    hasHandlers(enabled = false): boolean {
+        return enabled ? !!this.sortedHandlers.length : !!this.handlers.length;
+    }
+
     /**
      * Get the handlers for the current site.
      *
@@ -89,27 +94,15 @@ export class CoreSortedDelegate<
      * @returns Promise resolved with the handlers.
      */
     async getHandlersWhenLoaded(): Promise<DisplayType[]> {
-        if (this.loaded) {
+        await this.waitForReady();
-            return this.sortedHandlers;
-        }
 
-        const promisedHandlers = new CorePromisedValue<DisplayType[]>();
+        return this.sortedHandlers;
-        const subscription = this.getHandlersObservable().subscribe((handlers) => {
-            if (this.loaded) {
-                subscription?.unsubscribe();
-
-                // Return main handlers.
-                promisedHandlers.resolve(handlers);
-            }
-        });
-
-        return promisedHandlers;
     }
 
     /**
      * Update handlers Data.
      */
-    updateData(): void {
+    protected updateData(): void {
         const displayData: DisplayType[] = [];
 
         for (const name in this.enabledHandlers) {
@@ -125,7 +118,7 @@ export class CoreSortedDelegate<
         // Sort them by priority.
         displayData.sort((a, b) => (b.priority ?? 0) - (a.priority ?? 0));
 
-        this.loaded = true;
+        this.handlersLoaded = true;
         this.sortedHandlersRxJs.next(displayData);
         this.sortedHandlers = displayData;
     }

src/core/classes/delegate.ts

@@ -16,6 +16,8 @@ import { CoreSites } from '@services/sites';
 import { CoreEvents } from '@singletons/events';
 import { CoreSite } from '@classes/sites/site';
 import { CoreLogger } from '@singletons/logger';
+import { Subject, BehaviorSubject } from 'rxjs';
+import { CorePromisedValue } from './promised-value';
 
 /**
  * Superclass to help creating delegates
@@ -66,21 +68,14 @@ export class CoreDelegate<HandlerType extends CoreDelegateHandler> {
     protected updatePromises: {[siteId: string]: {[name: string]: Promise<void>}} = {};
 
     /**
-     * Whether handlers have been initialized.
+     * Subject to subscribe to handlers changes.
      */
-    protected handlersInitialized = false;
+    protected handlersUpdated: Subject<void> = new BehaviorSubject<void>(undefined);
 
     /**
-     * Promise to wait for handlers to be initialized.
+     * Handlers loaded flag.
-     *
-     * @returns Promise resolved when handlers are enabled.
      */
-    protected handlersInitPromise: Promise<boolean>;
+    protected handlersLoaded = false;
-
-    /**
-     * Function to resolve the handlers init promise.
-     */
-    protected handlersInitResolve!: (enabled: boolean) => void;
 
     /**
      * Constructor of the Delegate.
@@ -90,10 +85,6 @@ export class CoreDelegate<HandlerType extends CoreDelegateHandler> {
     constructor(delegateName: string) {
         this.logger = CoreLogger.getInstance(delegateName);
 
-        this.handlersInitPromise = new Promise((resolve): void => {
-            this.handlersInitResolve = resolve;
-        });
-
         // Update handlers on this cases.
         CoreEvents.on(CoreEvents.LOGIN, () => this.updateHandlers());
         CoreEvents.on(CoreEvents.SITE_UPDATED, () => this.updateHandlers());
@@ -120,6 +111,7 @@ export class CoreDelegate<HandlerType extends CoreDelegateHandler> {
     }
 
     /**
+     * Check if handlers are loaded.
      * Execute a certain function in a enabled handler.
      * If the handler isn't found or function isn't defined, call the same function in the default handler.
      *
@@ -216,12 +208,13 @@ export class CoreDelegate<HandlerType extends CoreDelegateHandler> {
     }
 
     /**
-     * Check if the delegate has at least 1 registered handler (not necessarily enabled).
+     * Returns if the delegate has any handler.
      *
-     * @returns If there is at least 1 handler.
+     * @param enabled Check only enabled handlers or all.
+     * @returns True if there's any registered handler, false otherwise.
      */
-    hasHandlers(): boolean {
+    hasHandlers(enabled = false): boolean {
-        return Object.keys(this.handlers).length > 0;
+        return enabled ? !!this.enabledHandlers.length : !!this.handlers.length;
     }
 
     /**
@@ -324,13 +317,16 @@ export class CoreDelegate<HandlerType extends CoreDelegateHandler> {
      *
      * @returns Resolved when done.
      */
-    async updateHandlers(): Promise<void> {
+    protected async updateHandlers(): Promise<void> {
+        this.handlersLoaded = false;
+
         const enabled = await this.isEnabled();
 
         if (!enabled) {
             this.logger.debug('Delegate not enabled.');
 
-            this.handlersInitResolve(false);
+            this.handlersLoaded = true;
+            this.handlersUpdated.next();
 
             return;
         }
@@ -355,10 +351,10 @@ export class CoreDelegate<HandlerType extends CoreDelegateHandler> {
 
         // Verify that this call is the last one that was started.
         if (this.isLastUpdateCall(now)) {
-            this.handlersInitialized = true;
-            this.handlersInitResolve(true);
-
             this.updateData();
+
+            this.handlersLoaded = true;
+            this.handlersUpdated.next();
         }
     }
 
@@ -366,10 +362,34 @@ export class CoreDelegate<HandlerType extends CoreDelegateHandler> {
      * Update handlers Data.
      * Override this function to update handlers data.
      */
-    updateData(): void {
+    protected updateData(): void {
         // To be overridden.
     }
 
+    /**
+     * Waits the handlers to be ready.
+     *
+     * @returns Resolved when the handlers are ready.
+     */
+    async waitForReady(): Promise<void> {
+        if (this.handlersLoaded) {
+            return;
+        }
+
+        const promise = new CorePromisedValue<void>();
+
+        const subscription = this.handlersUpdated.subscribe(() => {
+            if (this.handlersLoaded) {
+                // Resolve.
+                promise.resolve();
+
+                subscription?.unsubscribe();
+            }
+        });
+
+        return promise;
+    }
+
 }
 
 /**

src/core/features/block/services/block-delegate.ts

@@ -212,7 +212,7 @@ export class CoreBlockDelegateService extends CoreDelegate<CoreBlockHandler> {
      * Called when there are new block handlers available. Informs anyone who subscribed to the
      * observable.
      */
-    updateData(): void {
+    protected updateData(): void {
         this.blocksUpdateObservable.next();
     }
 

src/core/features/course/services/course-options-delegate.ts

@@ -26,6 +26,8 @@ import {
 import { CoreCourseAccessDataType } from '../constants';
 import { Params } from '@angular/router';
 import { makeSingleton } from '@singletons';
+import { Subject } from 'rxjs/internal/Subject';
+import { BehaviorSubject } from 'rxjs';
 import { CorePromisedValue } from '@classes/promised-value';
 import { CORE_COURSES_MY_COURSES_REFRESHED_EVENT } from '@features/courses/constants';
 
@@ -214,7 +216,8 @@ export interface CoreCourseOptionsMenuHandlerToDisplay {
 @Injectable( { providedIn: 'root' })
 export class CoreCourseOptionsDelegateService extends CoreDelegate<CoreCourseOptionsHandler> {
 
-    protected loaded: { [courseId: number]: boolean } = {};
+    protected courseHandlersUpdated: { [courseId: number]: Subject<void> } = {};
+    protected courseHandlersLoaded: { [courseId: number]: boolean } = {};
     protected lastUpdateHandlersForCoursesStart: {
         [courseId: number]: number;
     } = {};
@@ -224,7 +227,6 @@ export class CoreCourseOptionsDelegateService extends CoreDelegate<CoreCourseOpt
             access: CoreCourseAccess;
             navOptions?: CoreCourseUserAdminOrNavOptionIndexed;
             admOptions?: CoreCourseUserAdminOrNavOptionIndexed;
-            deferred: CorePromisedValue<void>;
             enabledHandlers: CoreCourseOptionsHandler[];
             enabledMenuHandlers: CoreCourseOptionsMenuHandler[];
         };
@@ -247,7 +249,7 @@ export class CoreCourseOptionsDelegateService extends CoreDelegate<CoreCourseOpt
      * @returns True if handlers are loaded, false otherwise.
      */
     areHandlersLoaded(courseId: number): boolean {
-        return !!this.loaded[courseId];
+        return !!this.courseHandlersLoaded[courseId];
     }
 
     /**
@@ -257,12 +259,12 @@ export class CoreCourseOptionsDelegateService extends CoreDelegate<CoreCourseOpt
      */
     protected clearCoursesHandlers(courseId?: number): void {
         if (courseId) {
-            if (!this.loaded[courseId]) {
+            if (!this.courseHandlersLoaded[courseId]) {
                 // Don't clear if not loaded, it's probably an ongoing load and it could cause JS errors.
                 return;
             }
 
-            this.loaded[courseId] = false;
+            this.courseHandlersLoaded[courseId] = false;
             delete this.coursesHandlers[courseId];
         } else {
             for (const courseId in this.coursesHandlers) {
@@ -321,7 +323,7 @@ export class CoreCourseOptionsDelegateService extends CoreDelegate<CoreCourseOpt
     ): Promise<void> {
 
         // If the handlers aren't loaded, do not refresh.
-        if (!this.loaded[courseId]) {
+        if (!this.courseHandlersLoaded[courseId]) {
             refresh = false;
         }
 
@@ -331,21 +333,20 @@ export class CoreCourseOptionsDelegateService extends CoreDelegate<CoreCourseOpt
                     access: accessData,
                     navOptions,
                     admOptions,
-                    deferred: new CorePromisedValue(),
                     enabledHandlers: [],
                     enabledMenuHandlers: [],
                 };
+                this.courseHandlersUpdated[courseId] = new BehaviorSubject<void>(undefined);
             } else {
                 this.coursesHandlers[courseId].access = accessData;
                 this.coursesHandlers[courseId].navOptions = navOptions;
                 this.coursesHandlers[courseId].admOptions = admOptions;
-                this.coursesHandlers[courseId].deferred = new CorePromisedValue();
             }
 
             this.updateHandlersForCourse(courseId, accessData, navOptions, admOptions);
         }
 
-        await this.coursesHandlers[courseId].deferred;
+        await this.waitCourseHandlersForReady(courseId);
     }
 
     /**
@@ -612,7 +613,7 @@ export class CoreCourseOptionsDelegateService extends CoreDelegate<CoreCourseOpt
     /**
      * Update handlers for each course.
      */
-    updateData(): void {
+    protected updateData(): void {
         // Update handlers for all courses.
         for (const courseId in this.coursesHandlers) {
             const handler = this.coursesHandlers[courseId];
@@ -635,6 +636,8 @@ export class CoreCourseOptionsDelegateService extends CoreDelegate<CoreCourseOpt
         navOptions?: CoreCourseUserAdminOrNavOptionIndexed,
         admOptions?: CoreCourseUserAdminOrNavOptionIndexed,
     ): Promise<void> {
+        this.courseHandlersLoaded[courseId] = false;
+
         const promises: Promise<void>[] = [];
         const enabledForCourse: CoreCourseOptionsHandler[] = [];
         const enabledForCourseMenu: CoreCourseOptionsMenuHandler[] = [];
@@ -675,13 +678,38 @@ export class CoreCourseOptionsDelegateService extends CoreDelegate<CoreCourseOpt
             // Update the coursesHandlers array with the new enabled addons.
             this.coursesHandlers[courseId].enabledHandlers = enabledForCourse;
             this.coursesHandlers[courseId].enabledMenuHandlers = enabledForCourseMenu;
-            this.loaded[courseId] = true;
 
-            // Resolve the promise.
+            // Notify changes.
-            this.coursesHandlers[courseId].deferred.resolve();
+            this.courseHandlersLoaded[courseId] = true;
+            this.courseHandlersUpdated[courseId].next();
         }
     }
 
+    /**
+     * Waits the course handlers to be ready.
+     *
+     * @param courseId The course ID.
+     * @returns Promise resolved when the handlers are ready.
+     */
+    async waitCourseHandlersForReady(courseId: number): Promise<void> {
+        if (this.courseHandlersLoaded[courseId]) {
+            return;
+        }
+
+        const promise = new CorePromisedValue<void>();
+
+        const subscription = this.courseHandlersUpdated[courseId].subscribe(() => {
+            if (this.courseHandlersLoaded[courseId]) {
+                // Resolve.
+                promise.resolve();
+
+                subscription?.unsubscribe();
+            }
+        });
+
+        return promise;
+    }
+
 }
 
 export const CoreCourseOptionsDelegate = makeSingleton(CoreCourseOptionsDelegateService);

src/core/features/filter/services/filter-delegate.ts

@@ -112,9 +112,9 @@ export class CoreFilterDelegateService extends CoreDelegate<CoreFilterHandler> {
         skipFilters?: string[],
         siteId?: string,
     ): Promise<string> {
-
         // Wait for filters to be initialized.
-        const enabled = await this.handlersInitPromise;
+        await this.waitForReady();
+        const enabled = this.hasHandlers(true);
         if (!enabled) {
             // No enabled filters, return the text.
             return text;
@@ -201,7 +201,8 @@ export class CoreFilterDelegateService extends CoreDelegate<CoreFilterHandler> {
     ): Promise<void> {
 
         // Wait for filters to be initialized.
-        const enabled = await this.handlersInitPromise;
+        await this.waitForReady();
+        const enabled = this.hasHandlers(true);
         if (!enabled) {
             return;
         }
@@ -276,7 +277,8 @@ export class CoreFilterDelegateService extends CoreDelegate<CoreFilterHandler> {
      */
     async shouldBeApplied(filters: CoreFilterFilter[], options: CoreFilterFormatTextOptions, site?: CoreSite): Promise<boolean> {
         // Wait for filters to be initialized.
-        const enabled = await this.handlersInitPromise;
+        await this.waitForReady();
+        const enabled = this.hasHandlers(true);
         if (!enabled) {
             return false;
         }

src/core/services/tests/plugin-file-delegate.test.ts

@@ -16,6 +16,7 @@ import { mock, mockSingleton } from '@/testing/utils';
 import { CoreSite } from '@classes/sites/site';
 import { CorePluginFileDelegateService, CorePluginFileHandler } from '@services/plugin-file-delegate';
 import { CoreSites } from '@services/sites';
+import { CoreEvents } from '@singletons/events';
 import { CoreUrl } from '@singletons/url';
 
 describe('CorePluginFileDelegate', () => {
@@ -32,7 +33,8 @@ describe('CorePluginFileDelegate', () => {
         pluginFileDelegate = new CorePluginFileDelegateService();
         pluginFileDelegate.registerHandler(new ModFooRevisionHandler());
 
-        await pluginFileDelegate.updateHandlers();
+        CoreEvents.trigger(CoreEvents.LOGIN, { siteId: '42' }, '42');
+        await pluginFileDelegate.waitForReady();
     });
 
     it('removes revision from a URL', () => {