feat: iframe messaging for component picker in problem bank (#35888)

cms/static/js/views/modals/select_v2_library_content.js

@@ -37,6 +37,10 @@ function($, _, gettext, BaseModal) {
                         this.disableActionButton('add');
                     }
                 }
+                if (event.data?.type === 'addSelectedComponentsToBank') {
+                    this.selections = event.data.payload.selectedComponents;
+                    this.callback(this.selections);
+                }
             };
             this.messageListener = window.addEventListener("message", handleMessage);
             this.cleanupListener = () => { window.removeEventListener("message", handleMessage) };
@@ -70,10 +74,20 @@ function($, _, gettext, BaseModal) {
          * Show a component picker modal from library.
          * @param contentPickerUrl Url for component picker
          * @param callback A function to call with the selected block(s)
+         * @param isIframeEmbed Boolean indicating if the unit is displayed inside an iframe
          */
-        showComponentPicker: function(contentPickerUrl, callback) {
+        showComponentPicker: function(contentPickerUrl, callback, isIframeEmbed) {
             this.contentPickerUrl = contentPickerUrl;
             this.callback = callback;
+            if (isIframeEmbed) {
+                window.parent.postMessage(
+                    {
+                        type: 'showMultipleComponentPicker',
+                        payload: {}
+                    }, document.referrer
+                );
+                return true;
+            }
 
             this.render();
             this.show();

cms/static/js/views/pages/container.js

@@ -524,7 +524,7 @@ function($, _, Backbone, gettext, BasePage,
                 ViewUtils.runOperationShowingMessage(gettext('Adding'), () => {
                     return lastAdded.done(() => { doneAddingAllBlocks() });
                 });
-            });
+            }, this.options.isIframeEmbed);
         },
 
         /**