meteor__coursera-meteor-2/textcircle.js

// Note: not Documents, but this.Documents, because of the editing package (?)
this.Documents = new Mongo.Collection("documents");

if (Meteor.isClient) {
  Template.editor.helpers({
    docid: function () {
      let doc = Documents.findOne();
      return doc ? doc._id : undefined;
    },
    config: function () {
      return function (editor) {
        editor.on("change", function (cm_editor, info) {
          let $preview = $("#viewer_iframe");
          $preview.contents().find("html").html(cm_editor.getValue());
        });
      };
    }
  });

}

if (Meteor.isServer) {
  Meteor.startup(function () {
    // startup code that creates a document in case there isn't one yet.
    if (!Documents.findOne()) {
      Documents.insert({ title: "my new document" });
    }
  });
}