gistfile1.js

	buildView: function() {
	  let window = windowUtils.getMostRecentBrowserWindow();
	  let doc = window.document;

	  let content = doc.getElementById("appcontent");

	  let splitter = doc.createElementNS(XUL_NS, 'splitter');
	  splitter.setAttribute("resizeafter","closest")
	  splitter.setAttribute("resizebefore","closest")

	  content.appendChild(splitter)
	  
	  let iframe = doc.createElementNS(XUL_NS, 'iframe');
	  iframe.setAttribute('type', 'chrome');
	  iframe.setAttribute("flex",1)
	  iframe.setAttribute("src",this.options.contentURL)
	  
	  content.appendChild(iframe);

	  iframe.addEventListener("DOMContentLoaded", e => {
	  	let contentWindow = e.target.ownerGlobal
 		this.initContent(contentWindow)
	  })

	}