Can edit settings on the embedding page

app/assets/javascripts/admin/controllers/admin-embedding.js.es6

@@ -1,9 +1,46 @@
+import computed from 'ember-addons/ember-computed-decorators';
+import { popupAjaxError } from 'discourse/lib/ajax-error';
+
 export default Ember.Controller.extend({
+  saved: false,
   embedding: null,
 
+  // show settings if we have at least one created host
+  @computed('embedding.embeddable_hosts.@each.isCreated')
+  showSecondary() {
+    const hosts = this.get('embedding.embeddable_hosts');
+    return hosts.length && hosts.findProperty('isCreated');
+  },
+
+  @computed('embedding.base_url')
+  embeddingCode(baseUrl) {
+
+    const html =
+`<div id='discourse-comments'></div>
+
+<script type="text/javascript">
+  DiscourseEmbed = { discourseUrl: '${baseUrl}/',
+                     discourseEmbedUrl: 'REPLACE_ME' };
+
+  (function() {
+    var d = document.createElement('script'); d.type = 'text/javascript'; d.async = true;
+    d.src = DiscourseEmbed.discourseUrl + 'javascripts/embed.js';
+    (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(d);
+  })();
+</script>`;
+
+    return html;
+  },
+
   actions: {
     saveChanges() {
-      this.get('embedding').update({});
+      const embedding = this.get('embedding');
+      const updates = embedding.getProperties(embedding.get('fields'));
+
+      this.set('saved', false);
+      this.get('embedding').update(updates).then(() => {
+        this.set('saved', true);
+      }).catch(popupAjaxError);
     },
 
     addHost() {