MOBILE-2235 iframe: Fix clicks in deep iframe links

src/providers/utils/iframe.ts

@@ -319,10 +319,32 @@ export class CoreIframeUtilsProvider {
             while (el && el.tagName !== 'A') {
                 el = el.parentElement;
             }
-            if (!el || el.tagName !== 'A') {
+
+            const link = <CoreIframeHTMLAnchorElement> el;
+            if (!link || link.treated) {
+                return;
+            }
+
+            // Add click listener to the link, this way if the iframe has added a listener to the link it will be executed first.
+            link.treated = true;
+            link.addEventListener('click', this.linkClicked.bind(this, element, link));
+        }, {
+            capture: true // Use capture to fix this listener not called if the element clicked is too deep in the DOM.
+        });
+    }
+
+    /**
+     * A link inside a frame was clicked.
+     *
+     * @param element Frame element.
+     * @param link Link clicked.
+     * @param event Click event.
+     */
+    protected linkClicked(element: HTMLFrameElement | HTMLObjectElement, link: HTMLAnchorElement, event: Event): void {
+        if (event.defaultPrevented) {
+            // Event already prevented by some other code.
             return;
         }
-            const link = <HTMLAnchorElement> el;
 
         const scheme = this.urlUtils.getUrlScheme(link.href);
         if (!link.href || (scheme && scheme == 'javascript')) {
@@ -334,7 +356,7 @@ export class CoreIframeUtilsProvider {
             // Scheme suggests it's an external resource.
             event.preventDefault();
 
-                const frameSrc = element.src || element.data,
+            const frameSrc = (<HTMLFrameElement> element).src || (<HTMLObjectElement> element).data,
                 frameScheme = this.urlUtils.getUrlScheme(frameSrc);
 
             // If the frame is not local, check the target to identify how to treat the link.
@@ -371,6 +393,12 @@ export class CoreIframeUtilsProvider {
                 element.setAttribute('src', link.href);
             }
         }
-        });
     }
 }
+
+/**
+ * Subtype of HTMLAnchorElement, with some calculated data.
+ */
+type CoreIframeHTMLAnchorElement = HTMLAnchorElement & {
+    treated?: boolean; // Whether the element has been treated already.
+};