MOBILE-3086 data: Fix syntax errors in templates

src/addon/mod/data/providers/helper.ts

@@ -598,6 +598,9 @@ export class AddonModDataHelperProvider {
     getTemplate(data: any, type: string, fields: any[]): string {
         let template = data[type] || this.getDefaultTemplate(type, fields);
 
+        // Try to fix syntax errors so the template can be parsed by Angular.
+        template = this.domUtils.fixHtml(template);
+
         // Add core-link directive to links.
         template = template.replace(/<a ([^>]*href="[^>]*)>/i, (match, attributes) => {
             return '<a core-link capture="true" ' + attributes + '>';

src/providers/utils/dom.ts

@@ -323,6 +323,33 @@ export class CoreDomUtilsProvider {
         return urls;
     }
 
+    /**
+     * Fix syntax errors in HTML.
+     *
+     * @param {string} html HTML text.
+     * @return {string} Fixed HTML text.
+     */
+    fixHtml(html: string): string {
+        this.template.innerHTML = html;
+
+        const attrNameRegExp = /[^\x00-\x20\x7F-\x9F"'>\/=]+/;
+
+        const fixElement = (element: Element): void => {
+            // Remove attributes with an invalid name.
+            Array.from(element.attributes).forEach((attr) => {
+                if (!attrNameRegExp.test(attr.name)) {
+                    element.removeAttributeNode(attr);
+                }
+            });
+
+            Array.from(element.children).forEach(fixElement);
+        };
+
+        Array.from(this.template.content.children).forEach(fixElement);
+
+        return this.template.innerHTML;
+    }
+
     /**
      * Focus an element and open keyboard.
      *