Apply changes from team members in own editor

app/assets/javascripts/channels/synchronized_editor_channel.js

@@ -0,0 +1,38 @@
+$(document).on('turbolinks:load', function () {
+
+  if (window.location.pathname.includes('/implement')) {
+    const editor = $('#editor');
+    const exercise_id = editor.data('exercise-id');
+    const current_user_id = editor.data('user-id');
+    const current_contributor_id = editor.data('contributor-id');
+
+    if ($.isController('exercises') && current_user_id !== current_contributor_id) {
+
+      App.synchronized_editor = App.cable.subscriptions.create({
+        channel: "SynchronizedEditorChannel", exercise_id: exercise_id
+      }, {
+
+
+        connected() {
+          // Called when the subscription is ready for use on the server
+        },
+
+        disconnected() {
+          // Called when the subscription has been terminated by the server
+        },
+
+        received(data) {
+          // Called when there's incoming data on the websocket for this channel
+          if (current_user_id !== data['current_user_id']) {
+            CodeOceanEditor.applyChanges(data['delta']['data']);
+          }
+        },
+
+        send_changes(delta) {
+          const delta_with_user_id = {current_user_id: current_user_id, delta: delta}
+          this.perform('send_changes', {delta_with_user_id: delta_with_user_id});
+        }
+      });
+    }
+  }
+});