MOBILE-3859 ws: Improve error message for certificate errors

scripts/langindex.json

@@ -1384,6 +1384,7 @@
   "core.add": "moodle",
   "core.agelocationverification": "moodle",
   "core.ago": "message",
+  "core.ajaxendpointnotfound": "local_moodlemobileapp",
   "core.all": "moodle",
   "core.allgroups": "moodle",
   "core.allparticipants": "moodle",
@@ -1405,6 +1406,7 @@
   "core.captureimage": "local_moodlemobileapp",
   "core.capturevideo": "local_moodlemobileapp",
   "core.category": "moodle",
+  "core.certificaterror": "local_moodlemobileapp",
   "core.choose": "moodle",
   "core.choosedots": "moodle",
   "core.clearsearch": "local_moodlemobileapp",

src/core/classes/errors/ajaxerror.ts

@@ -19,12 +19,10 @@ import { CoreError } from '@classes/errors/error';
  */
 export class CoreAjaxError extends CoreError {
 
-    available?: number; // Whether the AJAX call is available. 0 if unknown, 1 if available, -1 if not available.
+    available = 1; // @deprecated since app 4.0. AJAX endpoint should always be available in supported Moodle versions.
 
-    constructor(message: string, available?: number) {
+    constructor(message: string) {
         super(message);
-
-        this.available = typeof available == 'undefined' ? 0 : available;
     }
 
 }

src/core/classes/site.ts

@@ -1333,38 +1333,38 @@ export class CoreSite {
             siteUrl: this.siteUrl,
         };
 
-        let config: CoreSitePublicConfigResponse | undefined;
+        let config: CoreSitePublicConfigResponse;
 
         try {
-            config = await CoreWS.callAjax('tool_mobile_get_public_config', {}, preSets);
+            config = await CoreWS.callAjax<CoreSitePublicConfigResponse>('tool_mobile_get_public_config', {}, preSets);
         } catch (error) {
-            if ((!this.getInfo() || this.isVersionGreaterEqualThan('3.8')) && error && error.errorcode == 'codingerror') {
+            if (!error || error.errorcode !== 'codingerror' || (this.getInfo() && !this.isVersionGreaterEqualThan('3.8'))) {
-                // This error probably means that there is a redirect in the site. Try to use a GET request.
+                throw error;
-                preSets.noLogin = true;
-                preSets.useGet = true;
-
-                try {
-                    config = await CoreWS.callAjax('tool_mobile_get_public_config', {}, preSets);
-                } catch (error2) {
-                    if (this.getInfo() && this.isVersionGreaterEqualThan('3.8')) {
-                        // GET is supported, return the second error.
-                        throw error2;
-                    } else {
-                        // GET not supported or we don't know if it's supported. Return first error.
-                        throw error;
-                    }
-                }
             }
 
-            throw error;
+            // This error probably means that there is a redirect in the site. Try to use a GET request.
+            preSets.noLogin = true;
+            preSets.useGet = true;
+
+            try {
+                config = await CoreWS.callAjax<CoreSitePublicConfigResponse>('tool_mobile_get_public_config', {}, preSets);
+            } catch (error2) {
+                if (this.getInfo() && this.isVersionGreaterEqualThan('3.8')) {
+                    // GET is supported, return the second error.
+                    throw error2;
+                } else {
+                    // GET not supported or we don't know if it's supported. Return first error.
+                    throw error;
+                }
+            }
         }
 
         // Use the wwwroot returned by the server.
-        if (config!.httpswwwroot) {
+        if (config.httpswwwroot) {
-            this.siteUrl = CoreUrlUtils.removeUrlParams(config!.httpswwwroot); // Make sure the URL doesn't have params.
+            this.siteUrl = CoreUrlUtils.removeUrlParams(config.httpswwwroot); // Make sure the URL doesn't have params.
         }
 
-        return config!;
+        return config;
     }
 
     /**

src/core/lang.json

@@ -3,6 +3,7 @@
     "add": "Add",
     "agelocationverification": "Age and location verification",
     "ago": "{{$a}} ago",
+    "ajaxendpointnotfound": "<p>AJAX endpoint not found. This can happen if the Moodle site is too old or it blocks access to this endpoint. The Moodle app only supports Moodle systems {{$a}} onwards. Please contact your site administrator.</p>\n<p>{{whoisadmin}}</p>",
     "all": "All",
     "allgroups": "All groups",
     "allparticipants": "All participants",
@@ -23,6 +24,7 @@
     "captureimage": "Take picture",
     "capturevideo": "Record video",
     "category": "Category",
+    "certificaterror": "<p>The certificate of this site cannot be trusted by your device. Please contact your site administrator.</p>\n<p>{{whoisadmin}}</p>",
     "choose": "Choose",
     "choosedots": "Choose...",
     "clearsearch": "Clear search",

src/core/services/sites.ts

@@ -245,27 +245,24 @@ export class CoreSitesProvider {
                 });
             }
         } catch (error) {
-            // Error, check if not supported.
+            // Service supported but an error happened. Return error.
-            if (error.available === 1) {
+            if (error.errorcode == 'codingerror') {
-                // Service supported but an error happened. Return error.
+                // This could be caused by a redirect. Check if it's the case.
-                if (error.errorcode == 'codingerror') {
+                const redirect = await CoreUtils.checkRedirect(siteUrl);
-                    // This could be caused by a redirect. Check if it's the case.
-                    const redirect = await CoreUtils.checkRedirect(siteUrl);
 
-                    if (redirect) {
+                if (redirect) {
-                        error.error = Translate.instant('core.login.sitehasredirect');
+                    error.message = Translate.instant('core.login.sitehasredirect');
-                    } else {
+                } else {
-                        // We can't be sure if there is a redirect or not. Display cannot connect error.
+                    // We can't be sure if there is a redirect or not. Display cannot connect error.
-                        error.error = Translate.instant('core.cannotconnecttrouble');
+                    error.message = Translate.instant('core.cannotconnecttrouble');
-                    }
                 }
-
-                throw new CoreSiteError({
-                    message: error.error,
-                    errorcode: error.errorcode,
-                    critical: true,
-                });
             }
+
+            throw new CoreSiteError({
+                message: error.message,
+                errorcode: error.errorcode,
+                critical: true,
+            });
         }
 
         siteUrl = temporarySite.getURL();

src/core/services/ws.ts

@@ -37,6 +37,7 @@ import { CoreWSError } from '@classes/errors/wserror';
 import { CoreAjaxError } from '@classes/errors/ajaxerror';
 import { CoreAjaxWSError } from '@classes/errors/ajaxwserror';
 import { CoreNetworkError } from '@classes/errors/network-error';
+import { CoreSite } from '@classes/site';
 
 /**
  * This service allows performing WS calls and download/upload files.
@@ -474,9 +475,23 @@ export class CoreWSProvider {
 
             return data.data;
         }, (data) => {
-            const available = data.status == 404 ? -1 : 0;
+            let message = '';
 
-            throw new CoreAjaxError(Translate.instant('core.serverconnection'), available);
+            switch (data.status) {
+                case -2: // Certificate error.
+                    message = this.getCertificateErrorMessage(data.error);
+                    break;
+                case 404: // AJAX endpoint not found.
+                    message = Translate.instant('core.ajaxendpointnotfound', {
+                        $a: CoreSite.MINIMUM_MOODLE_VERSION,
+                        whoisadmin: Translate.instant('core.whoissiteadmin'),
+                    });
+                    break;
+                default:
+                    message = Translate.instant('core.serverconnection');
+            }
+
+            throw new CoreAjaxError(message);
         });
     }
 
@@ -675,12 +690,32 @@ export class CoreWSProvider {
                 }
 
                 return retryPromise;
+            } else if (error.status === -2) {
+                throw new CoreError(this.getCertificateErrorMessage(error.error));
             }
 
             throw new CoreError(Translate.instant('core.serverconnection'));
         });
     }
 
+    /**
+     * Get error message about certificate error.
+     *
+     * @param error Exact error message.
+     * @return Certificate error message.
+     */
+    protected getCertificateErrorMessage(error?: string): string {
+        const message = Translate.instant('core.certificaterror', {
+            whoisadmin: Translate.instant('core.whoissiteadmin'),
+        });
+
+        if (error) {
+            return `${message}\n<p>${error}</p>`;
+        }
+
+        return message;
+    }
+
     /**
      * Retry all requests in the queue.
      * This function uses recursion in order to add a delay between requests to reduce stress.