MOBILE-3101 core: Create singletons of all core providers

config/webpack.config.js

@@ -12,7 +12,8 @@ const customConfig = {
       '@providers': resolve('./src/providers'),
       '@components': resolve('./src/components'),
       '@directives': resolve('./src/directives'),
-      '@pipes': resolve('./src/pipes')
+      '@pipes': resolve('./src/pipes'),
+      '@singletons': resolve('./src/singletons'),
     }
   },
   externals: [

src/app/app.module.ts

@@ -14,7 +14,7 @@
 
 import { BrowserModule } from '@angular/platform-browser';
 import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
-import { NgModule, COMPILER_OPTIONS } from '@angular/core';
+import { NgModule, COMPILER_OPTIONS, Injector } from '@angular/core';
 import { IonicApp, IonicModule, Platform, Content, ScrollEvent, Config, Refresher } from 'ionic-angular';
 import { assert } from 'ionic-angular/util/util';
 import { HttpClient, HttpClientModule, HTTP_INTERCEPTORS } from '@angular/common/http';
@@ -155,6 +155,8 @@ import { AddonQtypeModule } from '@addon/qtype/qtype.module';
 import { AddonStorageManagerModule } from '@addon/storagemanager/storagemanager.module';
 import { AddonFilterModule } from '@addon/filter/filter.module';
 
+import { setSingletonsInjector } from '@singletons/core.singletons';
+
 // For translate loader. AoT requires an exported function for factories.
 export function createTranslateLoader(http: HttpClient): TranslateHttpLoader {
     return new TranslateHttpLoader(http, './assets/lang/', '.json');
@@ -357,6 +359,7 @@ export class AppModule {
             private eventsProvider: CoreEventsProvider,
             cronDelegate: CoreCronDelegate,
             siteInfoCronHandler: CoreSiteInfoCronHandler,
+            injector: Injector,
             ) {
         // Register a handler for platform ready.
         initDelegate.registerProcess({
@@ -391,6 +394,9 @@ export class AppModule {
         // Register handlers.
         cronDelegate.register(siteInfoCronHandler);
 
+        // Set the injector.
+        setSingletonsInjector(injector);
+
         // Set transition animation.
         config.setTransition('core-page-transition', CorePageTransition);
         config.setTransition('core-modal-lateral-transition', CoreModalLateralTransition);

src/classes/singletons-factory.ts

@@ -0,0 +1,76 @@
+// (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 { Injector, Type } from '@angular/core';
+
+/**
+ * Stub class used to type anonymous classes created in CoreSingletonsFactory#makeSingleton method.
+ */
+class CoreSingleton {}
+
+/**
+ * Token that can be used to resolve instances from the injector.
+ */
+export type CoreInjectionToken<Service> = Type<Service> | Type<any> | string;
+
+/**
+ * Singleton class created using the factory.
+ */
+export type CoreSingletonClass<Service> = typeof CoreSingleton & { instance: Service };
+
+/**
+ * Factory used to create CoreSingleton classes that get instances from an injector.
+ */
+export class CoreSingletonsFactory {
+
+    /**
+     * Angular injector used to resolve singleton instances.
+     */
+    private injector: Injector;
+
+    /**
+     * Set the injector that will be used to resolve instances in the singletons created with this factory.
+     *
+     * @param injector Injector.
+     */
+    setInjector(injector: Injector): void {
+        this.injector = injector;
+    }
+
+    /**
+     * Make a singleton that will hold an instance resolved from the factory injector.
+     *
+     * @param injectionToken Injection token used to resolve the singleton instance. This is usually the service class if the
+     * provider was defined using a class or the string used in the `provide` key if it was defined using an object.
+     */
+    makeSingleton<Service>(injectionToken: CoreInjectionToken<Service>): CoreSingletonClass<Service> {
+        // tslint:disable: no-this-assignment
+        const factory = this;
+
+        return class {
+
+            private static _instance: Service;
+
+            static get instance(): Service {
+                // Initialize instances lazily.
+                if (!this._instance) {
+                    this._instance = factory.injector.get(injectionToken);
+                }
+
+                return this._instance;
+            }
+
+        };
+    }
+}

src/core/compile/providers/compile.ts

@@ -56,7 +56,7 @@ import { Md5 } from 'ts-md5/dist/md5';
 
 // Import core classes that can be useful for site plugins.
 import { CoreSyncBaseProvider } from '@classes/base-sync';
-import { CoreUrl } from '@classes/utils/url';
+import { CoreUrl } from '@singletons/url';
 import { CoreCache } from '@classes/cache';
 import { CoreDelegate } from '@classes/delegate';
 import { CoreContentLinksHandlerBase } from '@core/contentlinks/classes/base-handler';

src/core/login/pages/site/site.ts

@@ -22,7 +22,7 @@ import { CoreUrlUtilsProvider } from '@providers/utils/url';
 import { CoreConfigConstants } from '../../../../configconstants';
 import { CoreLoginHelperProvider } from '../../providers/helper';
 import { FormBuilder, FormGroup, Validators } from '@angular/forms';
-import { CoreUrl } from '@classes/utils/url';
+import { CoreUrl } from '@singletons/url';
 import { TranslateService } from '@ngx-translate/core';
 
 /**

src/providers/app.ts

@@ -23,6 +23,7 @@ import { CoreLoggerProvider } from './logger';
 import { CoreEventsProvider } from './events';
 import { SQLiteDB, SQLiteDBTableSchema } from '@classes/sqlitedb';
 import { CoreConfigConstants } from '../configconstants';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Data stored for a redirect to another page/site.
@@ -703,3 +704,5 @@ export class CoreAppProvider {
         this.forceOffline = !!value;
     }
 }
+
+export class CoreApp extends makeSingleton(CoreAppProvider) {}

src/providers/config.ts

@@ -15,6 +15,7 @@
 import { Injectable } from '@angular/core';
 import { CoreAppProvider, CoreAppSchema } from './app';
 import { SQLiteDB } from '@classes/sqlitedb';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Factory to provide access to dynamic and permanent config and settings.
@@ -102,3 +103,5 @@ export class CoreConfigProvider {
         return this.appDB.insertRecord(this.TABLE_NAME, { name: name, value: value });
     }
 }
+
+export class CoreConfig extends makeSingleton(CoreConfigProvider) {}

src/providers/cron.ts

@@ -20,6 +20,7 @@ import { CoreLoggerProvider } from './logger';
 import { CoreUtilsProvider } from './utils/utils';
 import { CoreConstants } from '@core/constants';
 import { SQLiteDB } from '@classes/sqlitedb';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Interface that all cron handlers must implement.
@@ -554,3 +555,5 @@ export class CoreCronDelegate {
         delete this.handlers[name].timeout;
     }
 }
+
+export class CoreCron extends makeSingleton(CoreCronDelegate) {}

src/providers/db.ts

@@ -17,6 +17,7 @@ import { SQLite } from '@ionic-native/sqlite';
 import { Platform } from 'ionic-angular';
 import { SQLiteDB } from '@classes/sqlitedb';
 import { SQLiteDBMock } from '@core/emulator/classes/sqlitedb';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * This service allows interacting with the local database to store and retrieve data.
@@ -81,3 +82,5 @@ export class CoreDbProvider {
         });
     }
 }
+
+export class CoreDB extends makeSingleton(CoreDbProvider) {}

src/providers/events.ts

@@ -15,6 +15,7 @@
 import { Injectable } from '@angular/core';
 import { Subject } from 'rxjs';
 import { CoreLoggerProvider } from '@providers/logger';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Observer instance to stop listening to an event.
@@ -173,3 +174,5 @@ export class CoreEventsProvider {
         }
     }
 }
+
+export class CoreEvents extends makeSingleton(CoreEventsProvider) {}

src/providers/file-helper.ts

@@ -21,6 +21,7 @@ import { CoreSitesProvider } from './sites';
 import { CoreWSProvider } from './ws';
 import { CoreUtilsProvider } from './utils/utils';
 import { CoreConstants } from '@core/constants';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Provider to provide some helper functions regarding files and packages.
@@ -333,5 +334,6 @@ export class CoreFileHelperProvider {
 
         throw new Error('Couldn\'t determine file size: ' + file.fileurl);
     }
-
 }
+
+export class CoreFileHelper extends makeSingleton(CoreFileHelperProvider) {}

src/providers/file-session.ts

@@ -14,6 +14,7 @@
 
 import { Injectable } from '@angular/core';
 import { CoreSitesProvider } from './sites';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Helper to store some temporary data for file submission.
@@ -146,3 +147,5 @@ export class CoreFileSessionProvider {
         this.files[siteId][component][id] = newFiles;
     }
 }
+
+export class CoreFileSession extends makeSingleton(CoreFileSessionProvider) {}

src/providers/file.ts

@@ -21,6 +21,7 @@ import { CoreLoggerProvider } from './logger';
 import { CoreMimetypeUtilsProvider } from './utils/mimetype';
 import { CoreTextUtilsProvider } from './utils/text';
 import { Zip } from '@ionic-native/zip';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Progress event used when writing a file data into a file.
@@ -1270,3 +1271,5 @@ export class CoreFileProvider {
         return window.location.href;
     }
 }
+
+export class CoreFile extends makeSingleton(CoreFileProvider) {}

src/providers/filepool.ts

@@ -31,6 +31,7 @@ import { CoreUtilsProvider } from './utils/utils';
 import { SQLiteDB } from '@classes/sqlitedb';
 import { CoreConstants } from '@core/constants';
 import { Md5 } from 'ts-md5/dist/md5';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Entry from filepool.
@@ -3069,3 +3070,5 @@ export class CoreFilepoolProvider {
         });
     }
 }
+
+export class CoreFilepool extends makeSingleton(CoreFilepoolProvider) {}

src/providers/groups.ts

@@ -17,6 +17,7 @@ import { TranslateService } from '@ngx-translate/core';
 import { CoreSitesProvider } from './sites';
 import { CoreCoursesProvider } from '@core/courses/providers/courses';
 import { CoreSite, CoreSiteWSPreSets } from '@classes/site';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Group info for an activity.
@@ -449,3 +450,5 @@ export class CoreGroupsProvider {
         return groupInfo.defaultGroupId;
     }
 }
+
+export class CoreGroups extends makeSingleton(CoreGroupsProvider) {}

src/providers/init.ts

@@ -16,6 +16,7 @@ import { Injectable } from '@angular/core';
 import { Platform } from 'ionic-angular';
 import { CoreLoggerProvider } from './logger';
 import { CoreUtilsProvider } from './utils/utils';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Interface that all init handlers must implement.
@@ -175,3 +176,5 @@ export class CoreInitDelegate {
         this.initProcesses[handler.name] = handler;
     }
 }
+
+export class CoreInit extends makeSingleton(CoreInitDelegate) {}

src/providers/lang.ts

@@ -20,6 +20,7 @@ import { Platform, Config } from 'ionic-angular';
 import { CoreAppProvider } from '@providers/app';
 import { CoreConfigProvider } from './config';
 import { CoreConfigConstants } from '../configconstants';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /*
  * Service to handle language features, like changing the current language.
@@ -453,3 +454,5 @@ export class CoreLangProvider {
         }
     }
 }
+
+export class CoreLang extends makeSingleton(CoreLangProvider) {}

src/providers/local-notifications.ts

@@ -27,6 +27,7 @@ import { SQLiteDB } from '@classes/sqlitedb';
 import { CoreConstants } from '@core/constants';
 import { CoreConfigConstants } from '../configconstants';
 import { Subject, Subscription } from 'rxjs';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /*
  * Generated class for the LocalNotificationsProvider provider.
@@ -754,3 +755,5 @@ export class CoreLocalNotificationsProvider {
         return this.appDB.updateRecords(this.COMPONENTS_TABLE, {id: newId}, {id: oldId});
     }
 }
+
+export class CoreLocalNotifications extends makeSingleton(CoreLocalNotificationsProvider) {}

src/providers/logger.ts

@@ -14,6 +14,7 @@
 
 import { Injectable } from '@angular/core';
 import * as moment from 'moment';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Helper service to display messages in the console.
@@ -72,3 +73,5 @@ export class CoreLoggerProvider {
         };
     }
 }
+
+export class CoreLogger extends makeSingleton(CoreLoggerProvider) {}

src/providers/plugin-file-delegate.ts

@@ -19,6 +19,7 @@ import { CoreSitesProvider } from './sites';
 import { CoreWSExternalFile } from '@providers/ws';
 import { FileEntry } from '@ionic-native/file';
 import { CoreDelegate, CoreDelegateHandler } from '@classes/delegate';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Interface that all plugin file handlers must implement.
@@ -371,3 +372,5 @@ export class CorePluginFileDelegate extends CoreDelegate {
         return Promise.resolve();
     }
 }
+
+export class CorePluginFile extends makeSingleton(CorePluginFileDelegate) {}

src/providers/sites-factory.ts

@@ -14,6 +14,7 @@
 
 import { Injectable, Injector } from '@angular/core';
 import { CoreSite } from '@classes/site';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /*
  * Provider to create sites instances.
@@ -56,3 +57,5 @@ export class CoreSitesFactoryProvider {
         return methods;
     }
 }
+
+export class CoreSitesFactory extends makeSingleton(CoreSitesFactoryProvider) {}

src/providers/sites.ts

@@ -30,6 +30,7 @@ import { CoreSite, CoreSiteWSPreSets } from '@classes/site';
 import { SQLiteDB, SQLiteDBTableSchema } from '@classes/sqlitedb';
 import { Md5 } from 'ts-md5/dist/md5';
 import { WP_PROVIDER } from '@app/app.module';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Response of checking if a site exists and its configuration.
@@ -1925,5 +1926,6 @@ export class CoreSitesProvider {
                 return {};
         }
     }
-
 }
+
+export class CoreSites extends makeSingleton(CoreSitesProvider) {}

src/providers/sync.ts

@@ -15,6 +15,7 @@
 import { Injectable } from '@angular/core';
 import { CoreEventsProvider } from './events';
 import { CoreSitesProvider, CoreSiteSchema } from './sites';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /*
  * Service that provides some features regarding synchronization.
@@ -206,3 +207,5 @@ export class CoreSyncProvider {
         }
     }
 }
+
+export class CoreSync extends makeSingleton(CoreSyncProvider) {}

src/providers/update-manager.ts

@@ -17,6 +17,7 @@ import { CoreConfigProvider } from './config';
 import { CoreInitHandler, CoreInitDelegate } from './init';
 import { CoreLoggerProvider } from './logger';
 import { CoreConfigConstants } from '../configconstants';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Factory to handle app updates. This factory shouldn't be used outside of core.
@@ -59,3 +60,5 @@ export class CoreUpdateManagerProvider implements CoreInitHandler {
         });
     }
 }
+
+export class CoreUpdateManager extends makeSingleton<CoreUpdateManagerProvider>(CoreUpdateManagerProvider) {}

src/providers/urlschemes.ts

@@ -28,6 +28,7 @@ import { CoreContentLinksDelegate } from '@core/contentlinks/providers/delegate'
 import { CoreSitePluginsProvider } from '@core/siteplugins/providers/siteplugins';
 import { CoreConfigConstants } from '../configconstants';
 import { CoreConstants } from '@core/constants';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * All params that can be in a custom URL scheme.
@@ -488,3 +489,5 @@ export class CoreCustomURLSchemesProvider {
         return url.indexOf(CoreConfigConstants.customurlscheme + '://token=') != -1;
     }
 }
+
+export class CoreCustomURLSchemes extends makeSingleton(CoreCustomURLSchemesProvider) {}

src/providers/utils/dom.ts

@@ -30,6 +30,7 @@ import { CoreConstants } from '@core/constants';
 import { CoreBSTooltipComponent } from '@components/bs-tooltip/bs-tooltip';
 import { Md5 } from 'ts-md5/dist/md5';
 import { Subject } from 'rxjs';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Interface that defines an extension of the Ionic Alert class, to support multiple listeners.
@@ -1666,3 +1667,5 @@ export class CoreDomUtilsProvider {
         }, siteId);
     }
 }
+
+export class CoreDomUtils extends makeSingleton(CoreDomUtilsProvider) {}

src/providers/utils/iframe.ts

@@ -25,6 +25,7 @@ import { CoreTextUtilsProvider } from './text';
 import { CoreUrlUtilsProvider } from './url';
 import { CoreUtilsProvider } from './utils';
 import { CoreContentLinksHelperProvider } from '@core/contentlinks/providers/helper';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /*
  * "Utils" service with helper functions for iframes, embed and similar.
@@ -396,6 +397,8 @@ export class CoreIframeUtilsProvider {
     }
 }
 
+export class CoreIframeUtils extends makeSingleton(CoreIframeUtilsProvider) {}
+
 /**
  * Subtype of HTMLAnchorElement, with some calculated data.
  */

src/providers/utils/mimetype.ts

@@ -17,6 +17,7 @@ import { HttpClient } from '@angular/common/http';
 import { CoreLoggerProvider } from '../logger';
 import { TranslateService } from '@ngx-translate/core';
 import { CoreTextUtilsProvider } from './text';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /*
  * "Utils" service with helper functions for mimetypes and extensions.
@@ -549,3 +550,5 @@ export class CoreMimetypeUtilsProvider {
         return path;
     }
 }
+
+export class CoreMimetypeUtils extends makeSingleton(CoreMimetypeUtilsProvider) {}

src/providers/utils/text.ts

@@ -17,6 +17,7 @@ import { DomSanitizer, SafeUrl } from '@angular/platform-browser';
 import { ModalController, Platform } from 'ionic-angular';
 import { TranslateService } from '@ngx-translate/core';
 import { CoreLangProvider } from '../lang';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Different type of errors the app can treat.
@@ -1106,3 +1107,5 @@ export class CoreTextUtilsProvider {
         return _unserialize((data + ''), 0)[2];
     }
 }
+
+export class CoreTextUtils extends makeSingleton(CoreTextUtilsProvider) {}

src/providers/utils/time.ts

@@ -16,6 +16,7 @@ import { Injectable } from '@angular/core';
 import { TranslateService } from '@ngx-translate/core';
 import * as moment from 'moment';
 import { CoreConstants } from '@core/constants';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /*
  * "Utils" service with helper functions for date and time.
@@ -353,3 +354,5 @@ export class CoreTimeUtilsProvider {
         }
     }
 }
+
+export class CoreTimeUtils extends makeSingleton(CoreTimeUtilsProvider) {}

src/providers/utils/url.ts

@@ -15,6 +15,7 @@
 import { Injectable } from '@angular/core';
 import { CoreLangProvider } from '../lang';
 import { CoreTextUtilsProvider } from './text';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /*
  * "Utils" service with helper functions for URLs.
@@ -498,3 +499,5 @@ export class CoreUrlUtilsProvider {
         return url;
     }
 }
+
+export class CoreUrlUtils extends makeSingleton(CoreUrlUtilsProvider) {}

src/providers/utils/utils.ts

@@ -27,6 +27,7 @@ import { CoreLoggerProvider } from '../logger';
 import { TranslateService } from '@ngx-translate/core';
 import { CoreLangProvider } from '../lang';
 import { CoreWSProvider, CoreWSError } from '../ws';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * Deferred promise. It's similar to the result of $q.defer() in AngularJS.
@@ -1393,3 +1394,5 @@ export class CoreUtilsProvider {
         return filtered;
     }
 }
+
+export class CoreUtils extends makeSingleton(CoreUtilsProvider) {}

src/providers/ws.ts

@@ -24,6 +24,7 @@ import { CoreTextUtilsProvider } from './utils/text';
 import { CoreConstants } from '@core/constants';
 import { Md5 } from 'ts-md5/dist/md5';
 import { CoreInterceptor } from '@classes/interceptor';
+import { makeSingleton } from '@singletons/core.singletons';
 
 /**
  * PreSets accepted by the WS call.
@@ -879,6 +880,8 @@ export class CoreWSProvider {
     }
 }
 
+export class CoreWS extends makeSingleton(CoreWSProvider) {}
+
 /**
  * Error returned by a WS call.
  */

src/singletons/core.singletons.ts

@@ -0,0 +1,49 @@
+// (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 { AlertController, App } from 'ionic-angular';
+import { Injector } from '@angular/core';
+import { TranslateService } from '@ngx-translate/core';
+import { HttpClient } from '@angular/common/http';
+
+import { CoreSingletonsFactory, CoreInjectionToken, CoreSingletonClass } from '@classes/singletons-factory';
+
+const factory = new CoreSingletonsFactory();
+
+/**
+ * Set the injector that will be used to resolve instances in the singletons of this module.
+ *
+ * @param injector Module injector.
+ */
+export function setSingletonsInjector(injector: Injector): void {
+    factory.setInjector(injector);
+}
+
+/**
+ * Make a singleton for this module.
+ *
+ * @param injectionToken Injection token used to resolve the singleton instance. This is usually the service class if the
+ * provider was defined using a class or the string used in the `provide` key if it was defined using an object.
+ */
+export function makeSingleton<Service>(injectionToken: CoreInjectionToken<Service>): CoreSingletonClass<Service> {
+    return factory.makeSingleton(injectionToken);
+}
+
+export class Translate extends makeSingleton(TranslateService) {}
+
+export class Alerts extends makeSingleton(AlertController) {}
+
+export class Ionic extends makeSingleton(App) {}
+
+export class Http extends makeSingleton(HttpClient) {}

tsconfig.json

@@ -21,7 +21,8 @@
       "@providers/*": ["providers/*"],
       "@components/*": ["components/*"],
       "@directives/*": ["directives/*"],
-      "@pipes/*": ["pipes/*"]
+      "@pipes/*": ["pipes/*"],
+      "@singletons/*": ["singletons/*"]
     },
     "typeRoots": [
       "node_modules/@types"