MOBILE-2261 site: Implement sites factory and events provider

src/app/app.module.ts

@@ -26,6 +26,8 @@ import { CoreMimetypeUtilsProvider } from '../providers/utils/mimetype';
 import { CoreInitDelegate } from '../providers/init';
 import { CoreFileProvider } from '../providers/file';
 import { CoreWSProvider } from '../providers/ws';
+import { CoreEventsProvider } from '../providers/events';
+import { CoreSitesFactoryProvider } from '../providers/sites-factory';
 
 // For translate loader. AoT requires an exported function for factories.
 export function createTranslateLoader(http: HttpClient) {
@@ -72,7 +74,9 @@ export function createTranslateLoader(http: HttpClient) {
         CoreMimetypeUtilsProvider,
         CoreInitDelegate,
         CoreFileProvider,
-        CoreWSProvider
+        CoreWSProvider,
+        CoreEventsProvider,
+        CoreSitesFactoryProvider,
     ]
 })
 export class AppModule {

src/classes/sqlitedb.ts

@@ -303,12 +303,14 @@ export class SQLiteDB {
 
     /**
      * Execute a SQL query.
+     * IMPORTANT: Use this function only if you cannot use any of the other functions in this API. Please take into account that
+     * these query will be run in SQLite (Mobile) and Web SQL (desktop), so your query should work in both environments.
      *
      * @param {string} sql SQL query to execute.
      * @param {any[]} params Query parameters.
      * @return {Promise<any>} Promise resolved with the result.
      */
-    protected execute(sql: string, params?: any[]) : Promise<any> {
+    execute(sql: string, params?: any[]) : Promise<any> {
         return this.ready().then(() => {
             return this.db.executeSql(sql, params);
         });
@@ -316,16 +318,28 @@ export class SQLiteDB {
 
     /**
      * Execute a set of SQL queries. This operation is atomic.
+     * IMPORTANT: Use this function only if you cannot use any of the other functions in this API. Please take into account that
+     * these query will be run in SQLite (Mobile) and Web SQL (desktop), so your query should work in both environments.
      *
      * @param {any[]} sqlStatements SQL statements to execute.
      * @return {Promise<any>} Promise resolved with the result.
      */
-    protected executeBatch(sqlStatements: any[]) : Promise<any> {
+    executeBatch(sqlStatements: any[]) : Promise<any> {
         return this.ready().then(() => {
             return this.db.sqlBatch(sqlStatements);
         });
     }
 
+    /**
+     * Get all the records from a table.
+     *
+     * @param {string} table The table to query.
+     * @return {Promise<any>} Promise resolved with the records.
+     */
+    getAllRecords(table: string) : Promise<any> {
+        return this.getRecords(table);
+    }
+
     /**
      * Get a single field value from a table record where all the given conditions met.
      *

src/core/constants.ts

@@ -25,4 +25,5 @@ export class CoreConstants {
     public static dontShowError = 'CoreDontShowError';
     public static settingsRichTextEditor = 'CoreSettingsRichTextEditor';
     public static wsTimeout = 30000;
+    public static wsPrefix = 'local_mobile_';
 }

src/core/emulator/classes/sqlitedb.ts

@@ -78,12 +78,14 @@ export class SQLiteDBMock extends SQLiteDB {
 
     /**
      * Execute a SQL query.
+     * IMPORTANT: Use this function only if you cannot use any of the other functions in this API. Please take into account that
+     * these query will be run in SQLite (Mobile) and Web SQL (desktop), so your query should work in both environments.
      *
      * @param {string} sql SQL query to execute.
      * @param {any[]} params Query parameters.
      * @return {Promise<any>} Promise resolved with the result.
      */
-    protected execute(sql: string, params?: any[]) : Promise<any> {
+    execute(sql: string, params?: any[]) : Promise<any> {
         return new Promise((resolve, reject) => {
             // With WebSQL, all queries must be run in a transaction.
             this.db.transaction((tx) => {
@@ -96,11 +98,13 @@ export class SQLiteDBMock extends SQLiteDB {
 
     /**
      * Execute a set of SQL queries. This operation is atomic.
+     * IMPORTANT: Use this function only if you cannot use any of the other functions in this API. Please take into account that
+     * these query will be run in SQLite (Mobile) and Web SQL (desktop), so your query should work in both environments.
      *
      * @param {any[]} sqlStatements SQL statements to execute.
      * @return {Promise<any>} Promise resolved with the result.
      */
-    protected executeBatch(sqlStatements: any[]) : Promise<any> {
+    executeBatch(sqlStatements: any[]) : Promise<any> {
         return new Promise((resolve, reject) => {
             // Create a transaction to execute the queries.
             this.db.transaction((tx) => {

src/providers/events.ts

@@ -0,0 +1,127 @@
+// (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 } from '@angular/core';
+import { Subject } from 'rxjs';
+import { CoreLoggerProvider } from '../providers/logger';
+
+export interface CoreEventObserver {
+    off: () => void; // Unsubscribe.
+};
+
+/*
+ * Service to send and listen to events.
+ */
+@Injectable()
+export class CoreEventsProvider {
+    public static SESSION_EXPIRED = 'session_expired';
+    public static PASSWORD_CHANGE_FORCED = 'password_change_forced';
+    public static USER_NOT_FULLY_SETUP = 'user_not_fully_setup';
+    public static SITE_POLICY_NOT_AGREED = 'site_policy_not_agreed';
+    public static LOGIN = 'login';
+    public static LOGOUT = 'logout';
+    public static LANGUAGE_CHANGED = 'language_changed';
+    public static NOTIFICATION_SOUND_CHANGED = 'notification_sound_changed';
+    public static SITE_ADDED = 'site_added';
+    public static SITE_UPDATED = 'site_updated';
+    public static SITE_DELETED = 'site_deleted';
+    public static COMPLETION_MODULE_VIEWED = 'completion_module_viewed';
+    public static USER_DELETED = 'user_deleted';
+    public static PACKAGE_STATUS_CHANGED = 'package_status_changed';
+    public static SECTION_STATUS_CHANGED = 'section_status_changed';
+    public static REMOTE_ADDONS_LOADED = 'remote_addons_loaded';
+
+    logger;
+    observables = {};
+    uniqueEvents = {};
+
+    constructor(logger: CoreLoggerProvider) {
+        this.logger = logger.getInstance('CoreEventsProvider');
+    }
+
+    /**
+     * Listen for a certain event. To stop listening to the event:
+     * let observer = eventsProvider.on('something', myCallBack);
+     * ...
+     * observer.off();
+     *
+     * @param {string} eventName Name of the event to listen to.
+     * @param {Function} callBack Function to call when the event is triggered.
+     * @return {CoreEventObserver} Observer to stop listening.
+     */
+    on(eventName: string, callBack: Function) : CoreEventObserver {
+        // If it's a unique event and has been triggered already, call the callBack.
+        // We don't need to create an observer because the event won't be triggered again.
+        if (this.uniqueEvents[eventName]) {
+            callBack(this.uniqueEvents[eventName].data);
+            // Return a fake observer to prevent errors.
+            return {
+                off: () => {}
+            };
+        }
+
+        this.logger.debug(`New observer listening to event '${eventName}'`);
+
+        if (typeof this.observables[eventName] == 'undefined') {
+            // No observable for this event, create a new one.
+            this.observables[eventName] = new Subject<any>();
+        }
+
+        this.observables[eventName].subscribe(callBack);
+
+        // Create and return a CoreEventObserver.
+        return {
+            off: () => {
+                this.logger.debug(`Stop listening to event '${eventName}'`);
+                this.observables[eventName].unsubscribe(callBack);
+            }
+        };
+    }
+
+    /**
+     * Triggers an event, notifying all the observers.
+     *
+     * @param {string} event Name of the event to trigger.
+     * @param {any} data Data to pass to the observers.
+     */
+    trigger(eventName: string, data: any) : void {
+        this.logger.debug(`Event '${eventName}' triggered.`);
+        if (this.observables[eventName]) {
+            this.observables[eventName].next(data);
+        }
+    }
+
+    /**
+     * Triggers a unique event, notifying all the observers. If the event has already been triggered, don't do anything.
+     *
+     * @param {string} event Name of the event to trigger.
+     * @param {any} data Data to pass to the observers.
+     */
+    triggerUnique(eventName: string, data: any) : void {
+        if (this.uniqueEvents[eventName]) {
+            this.logger.debug(`Unique event '${eventName}' ignored because it was already triggered.`);
+        } else {
+            this.logger.debug(`Unique event '${eventName}' triggered.`);
+            // Store the data so it can be passed to observers that register from now on.
+            this.uniqueEvents[eventName] = {
+                data: data
+            };
+
+            // Now pass the data to observers.
+            if (this.observables[eventName]) {
+                this.observables[eventName].next(data);
+            }
+        }
+    }
+}

src/providers/sites-factory.ts

@@ -0,0 +1,57 @@
+// (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 { CoreSite } from '../classes/site';
+
+/*
+ * Provider to create sites instances.
+*/
+@Injectable()
+export class CoreSitesFactoryProvider {
+
+    constructor(private injector: Injector) {}
+
+    /**
+     * Make a site object.
+     *
+     * @param {string} id Site ID.
+     * @param {string} siteUrl Site URL.
+     * @param {string} token Site's WS token.
+     * @param {any} info Site info.
+     * @param {string} [privateToken] Private token.
+     * @param {any} [config] Site public config.
+     * @param {boolean} [loggedOut] Whether user is logged out.
+     * @return {CoreSite} Site instance.
+     * @description
+     * This returns a site object.
+     */
+    makeSite = function(id: string, siteUrl: string, token: string, info: any, privateToken?: string,
+            config?: any, loggedOut?: boolean) : CoreSite {
+        return new CoreSite(this.injector, id, siteUrl, token, info, privateToken, config, loggedOut);
+    }
+
+    /**
+     * Gets the list of Site methods.
+     *
+     * @return {string[]} List of methods.
+     */
+    getSiteMethods(): string[] {
+        let methods = [];
+        for (let name in CoreSite.prototype) {
+            methods.push(name);
+        }
+        return methods;
+    }
+}

src/providers/utils/text.ts

@@ -25,25 +25,6 @@ export class CoreTextUtilsProvider {
 
     constructor(private translate: TranslateService, private langProvider: CoreLangProvider) {}
 
-    /**
-     * Add or remove 'www' from a URL. The url needs to have http or https protocol.
-     *
-     * @param {string} url URL to modify.
-     * @return {string} Modified URL.
-     */
-    addOrRemoveWWW(url: string) : string {
-        if (url) {
-            if (url.match(/http(s)?:\/\/www\./)) {
-                // Already has www. Remove it.
-                url = url.replace('www.', '');
-            } else {
-                url = url.replace('https://', 'https://www.');
-                url = url.replace('http://', 'http://www.');
-            }
-        }
-        return url;
-    }
-
     /**
      * Given a list of sentences, build a message with all of them wrapped in <p>.
      *
@@ -326,47 +307,6 @@ export class CoreTextUtilsProvider {
         });
     }
 
-    /**
-     * Formats a URL, trim, lowercase, etc...
-     *
-     * @param {string} url The url to be formatted.
-     * @return {string} Fromatted url.
-     */
-    formatURL(url: string) : string {
-        url = url.trim();
-
-        // Check if the URL starts by http or https.
-        if (! /^http(s)?\:\/\/.*/i.test(url)) {
-            // Test first allways https.
-            url = 'https://' + url;
-        }
-
-        // http allways in lowercase.
-        url = url.replace(/^http/i, 'http');
-        url = url.replace(/^https/i, 'https');
-
-        // Replace last slash.
-        url = url.replace(/\/$/, "");
-
-        return url;
-    }
-
-    /**
-     * Given a URL, returns what's after the last '/' without params.
-     * Example:
-     * http://mysite.com/a/course.html?id=1 -> course.html
-     *
-     * @param {string} url URL to treat.
-     * @return {string} Last file without params.
-     */
-    getLastFileWithoutParams(url: string) : string {
-        let filename = url.substr(url.lastIndexOf('/') + 1);
-        if (filename.indexOf('?') != -1) {
-            filename = filename.substr(0, filename.indexOf('?'));
-        }
-        return filename;
-    }
-
     /**
      * Get the pluginfile URL to replace @@PLUGINFILE@@ wildcards.
      *
@@ -383,61 +323,6 @@ export class CoreTextUtilsProvider {
         return undefined;
     }
 
-    /**
-     * Get the protocol from a URL.
-     * E.g. http://www.google.com returns 'http'.
-     *
-     * @param {string} url URL to treat.
-     * @return {string} Protocol, undefined if no protocol found.
-     */
-    getUrlProtocol(url: string) : string {
-        if (!url) {
-            return;
-        }
-
-        let matches = url.match(/^([^\/:\.\?]*):\/\//);
-        if (matches && matches[1]) {
-            return matches[1];
-        }
-    }
-
-    /**
-     * Get the scheme from a URL. Please notice that, if a URL has protocol, it will return the protocol.
-     * E.g. javascript:doSomething() returns 'javascript'.
-     *
-     * @param {string} url URL to treat.
-     * @return {string} Scheme, undefined if no scheme found.
-     */
-    getUrlScheme(url: string) : string {
-        if (!url) {
-            return;
-        }
-
-        let matches = url.match(/^([a-z][a-z0-9+\-.]*):/);
-        if (matches && matches[1]) {
-            return matches[1];
-        }
-    }
-
-    /*
-     * Gets a username from a URL like: user@mysite.com.
-     *
-     * @param {string} url URL to treat.
-     * @return {string} Username. Undefined if no username found.
-     */
-    getUsernameFromUrl(url: string) : string {
-        if (url.indexOf('@') > -1) {
-            // Get URL without protocol.
-            let withoutProtocol = url.replace(/.*?:\/\//, ''),
-                matches = withoutProtocol.match(/[^@]*/);
-
-            // Make sure that @ is at the start of the URL, not in a param at the end.
-            if (matches && matches.length && !matches[0].match(/[\/|?]/)) {
-                return matches[0];
-            }
-        }
-    }
-
     /**
      * Check if a text contains HTML tags.
      *
@@ -498,20 +383,6 @@ export class CoreTextUtilsProvider {
         return json;
     }
 
-    /**
-     * Remove protocol and www from a URL.
-     *
-     * @param {string} url URL to treat.
-     * @return {string} Treated URL.
-     */
-    removeProtocolAndWWW(url: string) : string {
-        // Remove protocol.
-        url = url.replace(/.*?:\/\//g, '');
-        // Remove www.
-        url = url.replace(/^www./, '');
-        return url;
-    }
-
     /**
      * Replace all characters that cause problems with files in Android and iOS.
      *

src/providers/utils/url.ts

@@ -23,6 +23,25 @@ export class CoreUrlUtilsProvider {
 
     constructor(private langProvider: CoreLangProvider) {}
 
+    /**
+     * Add or remove 'www' from a URL. The url needs to have http or https protocol.
+     *
+     * @param {string} url URL to modify.
+     * @return {string} Modified URL.
+     */
+    addOrRemoveWWW(url: string) : string {
+        if (url) {
+            if (url.match(/http(s)?:\/\/www\./)) {
+                // Already has www. Remove it.
+                url = url.replace('www.', '');
+            } else {
+                url = url.replace('https://', 'https://www.');
+                url = url.replace('http://', 'http://www.');
+            }
+        }
+        return url;
+    }
+
     /**
      * Extracts the parameters from a URL and stores them in an object.
      *
@@ -41,6 +60,71 @@ export class CoreUrlUtilsProvider {
         return params;
     }
 
+    /**
+     * Generic function for adding the wstoken to Moodle urls and for pointing to the correct script.
+     * For download remote files from Moodle we need to use the special /webservice/pluginfile passing
+     * the ws token as a get parameter.
+     *
+     * @param {string} url The url to be fixed.
+     * @param {string} token Token to use.
+     * @return {string} Fixed URL.
+     */
+    fixPluginfileURL(url: string, token: string) : string {
+        if (!url || !token) {
+            return '';
+        }
+
+        // First check if we need to fix this url or is already fixed.
+        if (url.indexOf('token=') != -1) {
+            return url;
+        }
+
+        // Check if is a valid URL (contains the pluginfile endpoint).
+        if (!this.isPluginFileUrl(url)) {
+            return url;
+        }
+
+        // In which way the server is serving the files? Are we using slash parameters?
+        if (url.indexOf('?file=') != -1 || url.indexOf('?forcedownload=') != -1 || url.indexOf('?rev=') != -1) {
+            url += '&';
+        } else {
+            url += '?';
+        }
+        // Always send offline=1 (for external repositories). It shouldn't cause problems for local files or old Moodles.
+        url += 'token=' + token + '&offline=1';
+
+        // Some webservices returns directly the correct download url, others not.
+        if (url.indexOf('/webservice/pluginfile') == -1) {
+            url = url.replace('/pluginfile', '/webservice/pluginfile');
+        }
+        return url;
+    }
+
+    /**
+     * Formats a URL, trim, lowercase, etc...
+     *
+     * @param {string} url The url to be formatted.
+     * @return {string} Fromatted url.
+     */
+    formatURL(url: string) : string {
+        url = url.trim();
+
+        // Check if the URL starts by http or https.
+        if (! /^http(s)?\:\/\/.*/i.test(url)) {
+            // Test first allways https.
+            url = 'https://' + url;
+        }
+
+        // http allways in lowercase.
+        url = url.replace(/^http/i, 'http');
+        url = url.replace(/^https/i, 'https');
+
+        // Replace last slash.
+        url = url.replace(/\/$/, "");
+
+        return url;
+    }
+
     /**
      * Returns the URL to the documentation of the app, based on Moodle version and current language.
      *
@@ -67,6 +151,77 @@ export class CoreUrlUtilsProvider {
         });
     }
 
+    /**
+     * Given a URL, returns what's after the last '/' without params.
+     * Example:
+     * http://mysite.com/a/course.html?id=1 -> course.html
+     *
+     * @param {string} url URL to treat.
+     * @return {string} Last file without params.
+     */
+    getLastFileWithoutParams(url: string) : string {
+        let filename = url.substr(url.lastIndexOf('/') + 1);
+        if (filename.indexOf('?') != -1) {
+            filename = filename.substr(0, filename.indexOf('?'));
+        }
+        return filename;
+    }
+
+    /**
+     * Get the protocol from a URL.
+     * E.g. http://www.google.com returns 'http'.
+     *
+     * @param {string} url URL to treat.
+     * @return {string} Protocol, undefined if no protocol found.
+     */
+    getUrlProtocol(url: string) : string {
+        if (!url) {
+            return;
+        }
+
+        let matches = url.match(/^([^\/:\.\?]*):\/\//);
+        if (matches && matches[1]) {
+            return matches[1];
+        }
+    }
+
+    /**
+     * Get the scheme from a URL. Please notice that, if a URL has protocol, it will return the protocol.
+     * E.g. javascript:doSomething() returns 'javascript'.
+     *
+     * @param {string} url URL to treat.
+     * @return {string} Scheme, undefined if no scheme found.
+     */
+    getUrlScheme(url: string) : string {
+        if (!url) {
+            return;
+        }
+
+        let matches = url.match(/^([a-z][a-z0-9+\-.]*):/);
+        if (matches && matches[1]) {
+            return matches[1];
+        }
+    }
+
+    /*
+     * Gets a username from a URL like: user@mysite.com.
+     *
+     * @param {string} url URL to treat.
+     * @return {string} Username. Undefined if no username found.
+     */
+    getUsernameFromUrl(url: string) : string {
+        if (url.indexOf('@') > -1) {
+            // Get URL without protocol.
+            let withoutProtocol = url.replace(/.*?:\/\//, ''),
+                matches = withoutProtocol.match(/[^@]*/);
+
+            // Make sure that @ is at the start of the URL, not in a param at the end.
+            if (matches && matches.length && !matches[0].match(/[\/|?]/)) {
+                return matches[0];
+            }
+        }
+    }
+
     /**
      * Returns if a URL has any protocol (not a relative URL).
      *
@@ -128,42 +283,16 @@ export class CoreUrlUtilsProvider {
     }
 
     /**
-     * Generic function for adding the wstoken to Moodle urls and for pointing to the correct script.
+     * Remove protocol and www from a URL.
-     * For download remote files from Moodle we need to use the special /webservice/pluginfile passing
-     * the ws token as a get parameter.
      *
-     * @param {string} url The url to be fixed.
+     * @param {string} url URL to treat.
-     * @param {string} token Token to use.
+     * @return {string} Treated URL.
-     * @return {string} Fixed URL.
      */
-    fixPluginfileURL(url: string, token: string) : string {
+    removeProtocolAndWWW(url: string) : string {
-        if (!url || !token) {
+        // Remove protocol.
-            return '';
+        url = url.replace(/.*?:\/\//g, '');
-        }
+        // Remove www.
-
+        url = url.replace(/^www./, '');
-        // First check if we need to fix this url or is already fixed.
-        if (url.indexOf('token=') != -1) {
-            return url;
-        }
-
-        // Check if is a valid URL (contains the pluginfile endpoint).
-        if (!this.isPluginFileUrl(url)) {
-            return url;
-        }
-
-        // In which way the server is serving the files? Are we using slash parameters?
-        if (url.indexOf('?file=') != -1 || url.indexOf('?forcedownload=') != -1 || url.indexOf('?rev=') != -1) {
-            url += '&';
-        } else {
-            url += '?';
-        }
-        // Always send offline=1 (for external repositories). It shouldn't cause problems for local files or old Moodles.
-        url += 'token=' + token + '&offline=1';
-
-        // Some webservices returns directly the correct download url, others not.
-        if (url.indexOf('/webservice/pluginfile') == -1) {
-            url = url.replace('/pluginfile', '/webservice/pluginfile');
-        }
         return url;
     }
 

src/providers/utils/utils.ts

@@ -14,6 +14,7 @@
 
 import { Injectable } from '@angular/core';
 import { Platform } from 'ionic-angular';
+import { Observable } from 'rxjs';
 import { InAppBrowser, InAppBrowserObject } from '@ionic-native/in-app-browser';
 import { Clipboard } from '@ionic-native/clipboard';
 import { CoreAppProvider } from '../app';
@@ -349,6 +350,34 @@ export class CoreUtilsProvider {
         return this.allPromises(promises);
     }
 
+    /**
+     * Flatten an object, moving subobjects' properties to the first level using dot notation. E.g.:
+     * {a: {b: 1, c: 2}, d: 3} -> {'a.b': 1, 'a.c': 2, d: 3}
+     *
+     * @param {object} obj Object to flatten.
+     * @return {object} Flatten object.
+     */
+    flattenObject(obj: object) : object {
+        let toReturn = {};
+
+        for (let name in obj) {
+            if (!obj.hasOwnProperty(name)) continue;
+
+            if (typeof obj[name] == 'object') {
+                let flatObject = this.flattenObject(obj[name]);
+                for (let subName in flatObject) {
+                    if (!flatObject.hasOwnProperty(subName)) continue;
+
+                    toReturn[name + '.' + subName] = flatObject[subName];
+                }
+            } else {
+                toReturn[name] = obj[name];
+            }
+        }
+
+        return toReturn;
+    }
+
     /**
      * Given an array of strings, return only the ones that match a regular expression.
      *
@@ -916,6 +945,18 @@ export class CoreUtilsProvider {
         return mapped;
     }
 
+    /**
+     * Given an observable, convert it to a Promise that will resolve with the first received value.
+     *
+     * @param {Observable<any>} obs The observable to convert.
+     * @return {Promise<any>} Promise.
+     */
+    observableToPromise(obs: Observable<any>) : Promise<any> {
+        return new Promise((resolve, reject) => {
+            obs.subscribe(resolve, reject);
+        });
+    }
+
     /**
      * Similar to AngularJS $q.defer(). It will return an object containing the promise, and the resolve and reject functions.
      *
@@ -1021,6 +1062,17 @@ export class CoreUtilsProvider {
         return query.length ? query.substr(0, query.length - 1) : query;
     }
 
+    /**
+     * Stringify an object, sorting the properties. It doesn't sort arrays, only object properties. E.g.:
+     * {b: 2, a: 1} -> '{"a":1,"b":2}'
+     *
+     * @param {object} obj Object to stringify.
+     * @return {string} Stringified object.
+     */
+    sortAndStringify(obj: object) : string {
+        return JSON.stringify(obj, Object.keys(this.flattenObject(obj)).sort());
+    }
+
     /**
      * Sum the filesizes from a list of files checking if the size will be partial or totally calculated.
      *

src/providers/ws.ts

@@ -104,7 +104,7 @@ export class CoreWSProvider {
      * A wrapper function for a moodle WebService call.
      *
      * @param {string} method The WebService method to be called.
-     * @param {any} data Arguments to pass to the method.
+     * @param {any} data Arguments to pass to the method. It's recommended to call convertValuesToString before passing the data.
      * @param {CoreWSPreSets} preSets Extra settings and information.
      * @return {Promise} Promise resolved with the response data in success and rejected with the error message if it fails.
      */
@@ -123,13 +123,6 @@ export class CoreWSProvider {
             preSets.responseExpected = true;
         }
 
-        try {
-            data = this.convertValuesToString(data, preSets.cleanUnicode);
-        } catch (e) {
-            // Empty cleaned text found.
-            return Promise.reject(this.createFakeWSError('mm.core.unicodenotsupportedcleanerror', true));
-        }
-
         data.wsfunction = method;
         data.wstoken = preSets.wsToken;
         siteUrl = preSets.siteUrl + '/webservice/rest/server.php?moodlewsrestformat=json';
@@ -182,33 +175,32 @@ export class CoreWSProvider {
 
         siteUrl = preSets.siteUrl + '/lib/ajax/service.php';
 
-        return new Promise((resolve, reject) => {
+        let observable = this.http.post(siteUrl, JSON.stringify(ajaxData)).timeout(CoreConstants.wsTimeout);
-            this.http.post(siteUrl, JSON.stringify(ajaxData)).timeout(CoreConstants.wsTimeout).subscribe((data: any) => {
+        return this.utils.observableToPromise(observable).then((data: any) => {
-                // Some moodle web services return null. If the responseExpected value is set then so long as no data
+            // Some moodle web services return null. If the responseExpected value is set then so long as no data
-                // is returned, we create a blank object.
+            // is returned, we create a blank object.
-                if (!data && !preSets.responseExpected) {
+            if (!data && !preSets.responseExpected) {
-                    data = [{}];
+                data = [{}];
-                }
+            }
 
-                // Check if error. Ajax layer should always return an object (if error) or an array (if success).
+            // Check if error. Ajax layer should always return an object (if error) or an array (if success).
-                if (!data || typeof data != 'object') {
+            if (!data || typeof data != 'object') {
-                    return rejectWithError(this.translate.instant('mm.core.serverconnection'));
+                return rejectWithError(this.translate.instant('mm.core.serverconnection'));
-                } else if (data.error) {
+            } else if (data.error) {
-                    return rejectWithError(data.error, data.errorcode);
+                return rejectWithError(data.error, data.errorcode);
-                }
+            }
 
-                // Get the first response since only one request was done.
+            // Get the first response since only one request was done.
-                data = data[0];
+            data = data[0];
 
-                if (data.error) {
+            if (data.error) {
-                    return rejectWithError(data.exception.message, data.exception.errorcode);
+                return rejectWithError(data.exception.message, data.exception.errorcode);
-                }
+            }
 
-                return data.data;
+            return data.data;
-            }, (data) => {
+        }, (data) => {
-                let available = data.status == 404 ? -1 : 0;
+            let available = data.status == 404 ? -1 : 0;
-                return rejectWithError(this.translate.instant('mm.core.serverconnection'), '', available);
+            return rejectWithError(this.translate.instant('mm.core.serverconnection'), '', available);
-            });
         });
 
         // Convenience function to return an error.
@@ -237,7 +229,7 @@ export class CoreWSProvider {
      * @param {boolean} [stripUnicode] If Unicode long chars need to be stripped.
      * @return {object} The cleaned object, with multilevel array and objects preserved.
      */
-    protected convertValuesToString(data: object, stripUnicode?: boolean) : object {
+    convertValuesToString(data: object, stripUnicode?: boolean) : object {
         let result;
         if (!Array.isArray(data) && typeof data == 'object') {
             result = {};
@@ -435,10 +427,7 @@ export class CoreWSProvider {
         let promise = this.getPromiseHttp('head', url);
 
         if (!promise) {
-            promise = new Promise((resolve, reject) => {
+            promise = this.utils.observableToPromise(this.http.head(url).timeout(CoreConstants.wsTimeout));
-                this.http.head(url).timeout(CoreConstants.wsTimeout).subscribe(resolve, reject);
-            });
-
             this.setPromiseHttp(promise, 'head', url);
         }
 
@@ -455,58 +444,58 @@ export class CoreWSProvider {
      * @return {Promise<any>} Promise resolved with the response data in success and rejected with CoreWSError if it fails.
      */
     performPost(method: string, siteUrl: string, ajaxData: any, preSets: CoreWSPreSets) : Promise<any> {
-        // Create the promise for the request.
+        // Perform the post request.
-        let promise = new Promise((resolve, reject) => {
+        let observable = this.http.post(siteUrl, ajaxData).timeout(CoreConstants.wsTimeout),
+            promise;
 
-            this.http.post(siteUrl, ajaxData).timeout(CoreConstants.wsTimeout).subscribe((data: any) => {
+        promise = this.utils.observableToPromise(observable).then((data: any) => {
-                // Some moodle web services return null.
+            // Some moodle web services return null.
-                // If the responseExpected value is set to false, we create a blank object if the response is null.
+            // If the responseExpected value is set to false, we create a blank object if the response is null.
-                if (!data && !preSets.responseExpected) {
+            if (!data && !preSets.responseExpected) {
-                    data = {};
+                data = {};
-                }
+            }
-
-                if (!data) {
-                    return Promise.reject(this.createFakeWSError('mm.core.serverconnection', true));
-                } else if (typeof data != preSets.typeExpected) {
-                    this.logger.warn('Response of type "' + typeof data + `" received, expecting "${preSets.typeExpected}"`);
-                    return Promise.reject(this.createFakeWSError('mm.core.errorinvalidresponse', true));
-                }
-
-                if (typeof data.exception !== 'undefined') {
-                    return Promise.reject(data);
-                }
-
-                if (typeof data.debuginfo != 'undefined') {
-                    return Promise.reject(this.createFakeWSError('Error. ' + data.message));
-                }
-
-                return data;
-            }, (error) => {
-                // If server has heavy load, retry after some seconds.
-                if (error.status == 429) {
-                    let retryPromise = this.addToRetryQueue(method, siteUrl, ajaxData, preSets);
-
-                    // Only process the queue one time.
-                    if (this.retryTimeout == 0) {
-                        this.retryTimeout = parseInt(error.headers('Retry-After'), 10) || 5;
-                        this.logger.warn(`${error.statusText}. Retrying in ${this.retryTimeout} seconds. ` +
-                                        `${this.retryCalls.length} calls left.`);
-
-                        setTimeout(() => {
-                            this.logger.warn(`Retrying now with ${this.retryCalls.length} calls to process.`);
-                            // Finish timeout.
-                            this.retryTimeout = 0;
-                            this.processRetryQueue();
-                        }, this.retryTimeout * 1000);
-                    } else {
-                        this.logger.warn('Calls locked, trying later...');
-                    }
-
-                    return retryPromise;
-                }
 
+            if (!data) {
                 return Promise.reject(this.createFakeWSError('mm.core.serverconnection', true));
-            });
+            } else if (typeof data != preSets.typeExpected) {
+                this.logger.warn('Response of type "' + typeof data + `" received, expecting "${preSets.typeExpected}"`);
+                return Promise.reject(this.createFakeWSError('mm.core.errorinvalidresponse', true));
+            }
+
+            if (typeof data.exception !== 'undefined') {
+                return Promise.reject(data);
+            }
+
+            if (typeof data.debuginfo != 'undefined') {
+                return Promise.reject(this.createFakeWSError('Error. ' + data.message));
+            }
+
+            return data;
+        }, (error) => {
+            // If server has heavy load, retry after some seconds.
+            if (error.status == 429) {
+                let retryPromise = this.addToRetryQueue(method, siteUrl, ajaxData, preSets);
+
+                // Only process the queue one time.
+                if (this.retryTimeout == 0) {
+                    this.retryTimeout = parseInt(error.headers('Retry-After'), 10) || 5;
+                    this.logger.warn(`${error.statusText}. Retrying in ${this.retryTimeout} seconds. ` +
+                                    `${this.retryCalls.length} calls left.`);
+
+                    setTimeout(() => {
+                        this.logger.warn(`Retrying now with ${this.retryCalls.length} calls to process.`);
+                        // Finish timeout.
+                        this.retryTimeout = 0;
+                        this.processRetryQueue();
+                    }, this.retryTimeout * 1000);
+                } else {
+                    this.logger.warn('Calls locked, trying later...');
+                }
+
+                return retryPromise;
+            }
+
+            return Promise.reject(this.createFakeWSError('mm.core.serverconnection', true));
         });
 
         this.setPromiseHttp(promise, 'post', preSets.siteUrl, ajaxData);