Koenig - Fixed .cleanup when called during editor initialisation

refs TryGhost/Ghost#9724
- we call `koenig.cleanup` when setting a post in the editor controller but the call will happen before `componentCards` has been populated so none of our "delete if empty" routines were being run
- calls to `.cleanup` now schedule the cleanup after the next editor render which should mean cards are populated before we try to remove them

Author: kevinansfield

lib/koenig-editor/addon/components/koenig-editor.js

@@ -394,6 +394,10 @@ export default Component.extend({
                 this._startedRunLoop = false;
                 run.end();
             }
+
+            if (this._cleanupScheduled) {
+                run.schedule('afterRender', this, this._cleanup);
+            }
         });
 
         editor.postDidChange(() => {
@@ -624,16 +628,28 @@ export default Component.extend({
     },
 
     /* public interface ----------------------------------------------------- */
-    // TODO: find a better way to expose this?
-
+    // TODO: find a better way to expose the public interface?
+
+    // HACK: this scheduled cleanup is a bit hacky. We call .cleanup when
+    // initializing Koenig in our editor controller but we have to wait for
+    // rendering to finish so that componentCards is populated, even then
+    // it's unlikely the card.component registration has finished.
+    //
+    // TODO: see if there's a way we can perform cleanup directly on the
+    // mobiledoc, maybe with a "cleanupOnInit" option so that we modify the
+    // mobiledoc before we start rendering
     cleanup() {
+        this._cleanupScheduled = true;
+    },
+
+    _cleanup() {
         this.componentCards.forEach((card) => {
-            if (!card.koenigOptions.deleteIfEmpty) {
+            let shouldDelete = card.koenigOptions.deleteIfEmpty;
+
+            if (!shouldDelete) {
                 return;
             }
 
-            let shouldDelete = card.koenigOptions.deleteIfEmpty;
-
             if (typeof shouldDelete === 'string') {
                 let payloadKey = shouldDelete;
                 shouldDelete = card => isBlank(get(card, payloadKey));
@@ -643,6 +659,7 @@ export default Component.extend({
                 this.deleteCard(card, NO_CURSOR_MOVEMENT);
             }
         });
+        this._cleanupScheduled = false;
     },
 
     /* mobiledoc event handlers --------------------------------------------- */