Check if a page is iframed, add iframe specific enhancements.

check_if_pymChild.js

// This is meant to be included on child frames created with http://blog.apps.npr.org/pym.js/
// This script checks if our page is iframed, and if so, induces it to cooperate.
// This can allow us to use the same template for all pages on a site, and make being a child iframe an option for any page.
document.addEventListener('DOMContentLoaded', function () {
  var inIFrame = (window.location != window.parent.location) ? true : false;
  if(inIFrame) {
    // If this page is in a iframe...
    // ... Load pym.js into this page.
    var pymjs = document.createElement('script');
    pymjs.src = 'https://pym.nprapps.org/pym.v1.min.js';
    document.head.appendChild(pymjs);
    pymjs.onload = function () {
      // On pym.js load send the height to the parent page.
      var pymChild = new pym.Child();
      pymChild.sendHeight();
    };
    // ...add a class we can style against.
    document.body.className += ' iframed';
    // ...Add target="_parent" to links so they bust out of iframe.
    var links = document.getElementsByTagName('a');
    var len = links.length;
    for(var i=0; i<len; i++) {
      if (links[i].target != "_self") {
        links[i].target = "_parent";
      }
    }
  }
});

// Simple resize function we can use on the AJAX-y pages.
function pymResize() {
  // If we're in an iframe, send a resize event.
  if (window.location != window.parent.location) {
    var pymChild = new pym.Child();
    pymChild.sendHeight();
  }
};