MOBILE-2553 login: Detect redirect if login fails

scripts/langindex.json

@@ -1349,6 +1349,7 @@
   "core.login.selectsite": "local_moodlemobileapp",
   "core.login.signupplugindisabled": "local_moodlemobileapp",
   "core.login.siteaddress": "local_moodlemobileapp",
+  "core.login.sitehasredirect": "local_moodlemobileapp",
   "core.login.siteinmaintenance": "local_moodlemobileapp",
   "core.login.sitepolicynotagreederror": "local_moodlemobileapp",
   "core.login.siteurl": "local_moodlemobileapp",

src/core/login/lang/en.json

@@ -71,6 +71,7 @@
     "selectsite": "Please select your site:",
     "signupplugindisabled": "{{$a}} is not enabled.",
     "siteaddress": "Site address",
+    "sitehasredirect": "Your site contains at least one HTTP redirect. The app cannot follow redirects, this could be the issue that's preventing the app from connecting to your site.",
     "siteinmaintenance": "Your site is in maintenance mode",
     "sitepolicynotagreederror": "Site policy not agreed.",
     "siteurl": "Site URL",

src/providers/sites.ts

@@ -422,7 +422,8 @@ export class CoreSitesProvider {
                 password: password,
                 service: service
             },
-            promise = this.http.post(siteUrl + '/login/token.php', params).timeout(CoreConstants.WS_TIMEOUT).toPromise();
+            loginUrl = siteUrl + '/login/token.php',
+            promise = this.http.post(loginUrl, params).timeout(CoreConstants.WS_TIMEOUT).toPromise();
 
         return promise.then((data: any): any => {
             if (typeof data == 'undefined') {
@@ -431,12 +432,22 @@ export class CoreSitesProvider {
                 if (typeof data.token != 'undefined') {
                     return { token: data.token, siteUrl: siteUrl, privateToken: data.privatetoken };
                 } else {
+
                     if (typeof data.error != 'undefined') {
                         // We only allow one retry (to avoid loops).
                         if (!retry && data.errorcode == 'requirecorrectaccess') {
                             siteUrl = this.urlUtils.addOrRemoveWWW(siteUrl);
 
                             return this.getUserToken(siteUrl, username, password, service, true);
+                        } else if (data.errorcode == 'missingparam') {
+                            // It seems the server didn't receive all required params, it could be due to a redirect.
+                            return this.utils.checkRedirect(loginUrl).then((redirect) => {
+                                if (redirect) {
+                                    return Promise.reject({ error: this.translate.instant('core.login.sitehasredirect') });
+                                } else {
+                                    return Promise.reject({ error: data.error, errorcode: data.errorcode });
+                                }
+                            });
                         } else if (typeof data.errorcode != 'undefined') {
                             return Promise.reject({ error: data.error, errorcode: data.errorcode });
                         } else {

src/providers/utils/utils.ts

@@ -26,6 +26,7 @@ import { CoreLoggerProvider } from '../logger';
 import { TranslateService } from '@ngx-translate/core';
 import { CoreLangProvider } from '../lang';
 import { CoreWSProvider, CoreWSError } from '../ws';
+import { CoreConstants } from '@core/constants';
 
 /**
  * Deferred promise. It's similar to the result of $q.defer() in AngularJS.
@@ -182,6 +183,43 @@ export class CoreUtilsProvider {
         return;
     }
 
+    /**
+     * Check if a URL has a redirect.
+     *
+     * @param {string} url The URL to check.
+     * @return {Promise<boolean>} Promise resolved with boolean_ whether there is a redirect.
+     */
+    checkRedirect(url: string): Promise<boolean> {
+        if (window.fetch) {
+            const win = <any> window, // Convert to <any> to be able to use AbortController (not supported by our TS version).
+                initOptions: any = {
+                    redirect: 'follow'
+                };
+            let controller;
+
+            // Some browsers implement fetch but no AbortController.
+            if (win.AbortController) {
+                controller = new win.AbortController();
+                initOptions.signal = controller.signal;
+            }
+
+            return this.timeoutPromise(window.fetch(url, initOptions), CoreConstants.WS_TIMEOUT).then((response: Response) => {
+                return response.redirected;
+            }).catch((error) => {
+                if (error.timeout && controller) {
+                    // Timeout, abort the request.
+                    controller.abort();
+                }
+
+                // There was a timeout, cannot determine if there's a redirect. Assume it's false.
+                return false;
+            });
+        } else {
+            // Cannot check if there is a redirect, assume it's false.
+            return Promise.resolve(false);
+        }
+    }
+
     /**
      * Close the InAppBrowser window.
      *
@@ -1082,6 +1120,26 @@ export class CoreUtilsProvider {
         return result;
     }
 
+    /**
+     * Set a timeout to a Promise. If the time passes before the Promise is resolved or rejected, it will be automatically
+     * rejected.
+     *
+     * @param {Promise<T>} promise The promise to timeout.
+     * @param {number} time Number of milliseconds of the timeout.
+     * @return {Promise<T>} Promise with the timeout.
+     */
+    timeoutPromise<T>(promise: Promise<T>, time: number): Promise<T> {
+        return new Promise((resolve, reject): void => {
+            const timeout = setTimeout(() => {
+                reject({timeout: true});
+            }, time);
+
+            promise.then(resolve).catch(reject).finally(() => {
+                clearTimeout(timeout);
+            });
+        });
+    }
+
     /**
      * Converts locale specific floating point/comma number back to standard PHP float value.
      * Do NOT try to do any math operations before this conversion on any user submitted floats!