title: How to pass a variable from one HTML window to another in Electron?
body: <p>I am creating an Electron Desktop App and I am struggling with what might be a very simple concept. Let's say I have two HTML pages (we'll call this <code>foo.html</code> and <code>bar.html</code>).
  <code>foo.html</code> is the initial page in my program and once the user clicks the submit or next button a new window is spawned (on top of <code>foo.html</code>) and shows the content of <code>bar.html</code>. 
  Some values are produced and visualized and presented to the user in this <code>bar.html</code>. At this point both pages are open and once the user closes <code>bar.html</code> I want to pass some values from this page and display it in a text field or a table in my <code>foo.html</code>. 
  I am confused on how to approach this problem. Essentially how do I pass back a value to an HTML page which has already been rendered? </p>
  
  <p>Any help would be appreciated. </p>
  
  <p>Thank you</p>