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

import discourseComputed from "discourse-common/utils/decorators";
import Controller from "@ember/controller";
import { popupAjaxError } from "discourse/lib/ajax-error";

export default Controller.extend({
  saved: false,
  embedding: null,

  // show settings if we have at least one created host
  @discourseComputed("embedding.embeddable_hosts.@each.isCreated")
  showSecondary() {
    const hosts = this.get("embedding.embeddable_hosts");
    return hosts.length && hosts.findBy("isCreated");
  },

  @discourseComputed("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() {
      const embedding = this.embedding;
      const updates = embedding.getProperties(embedding.get("fields"));

      this.set("saved", false);
      this.embedding
        .update(updates)
        .then(() => this.set("saved", true))
        .catch(popupAjaxError);
    },

    addHost() {
      const host = this.store.createRecord("embeddable-host");
      this.get("embedding.embeddable_hosts").pushObject(host);
    },

    deleteHost(host) {
      this.get("embedding.embeddable_hosts").removeObject(host);
    }
  }
});