TypeError: window is null

[halcwb]

I am trying your code in a webix app. However in the function:

function createWindowFromIframe(element) {
  var win = getWindowFromElement(element);
  var callbackKey = "create-blockly-" + (new Date).getTime();
  var iframeWin = null;
  win[callbackKey] = function(callbackWin) {
    delete win[callbackKey];
    iframeWin = callbackWin;
  };
  iframe({
    container: element,
    html: iframeHtml.replace("{{callbackKey}}", JSON.stringify(callbackKey))
  });
  return iframeWin;
}

iframeWin is of course null. Then in instantiateBrowserCode, the function is called with window = null resulting in the error:

function instantiateBrowserCode(code, window) {
  var mockGoog = {require: function(){}, provide: function(){}};
  var creator = new Function(["window", "document", "Blockly", "goog"], code);
  creator.apply(window, [window, window.document, window.Blockly, mockGoog]);
}

Am I missing something? See: https://github.com/halcwb/GenPDMS/blob/blockly/client/src/controllers/ruleEditor.js

P.s. $$("rule_editor").getNode() returns a regular div. In fact, an iframe in that div get's created!