Get the content of an iFrame

iFrameContent.js

// Sometimes it's needed to get access to body or head elements within an iFrame.
// Here is a peace of code that helps to do this without jQuery.

var iFrameContent = window.iFrameContent || {};

iFrameContent.withIn = function(iFrameElement) {
  if (!iFrameElement) {
    throw 'Please, specify an iFrame to work with';
  }
  if (iFrameElement.nodeName !== 'IFRAME') {
    throw 'iFrame element is expected';
  }

  var doc = iFrameElement.contentWindow || iFrameElement.contentDocument;

  return {
    getHead: function() {
      return doc.document ? doc.document.head : null;
    },
    getBody: function() {
      return doc.document ? doc.document.body : null;
    }
  }
};

// Usage
// <iframe id="myWindow"></iframe>

var iFrameElem = document.querySelector('#myWindow');
var iFrameBody = iFrameContent.withIn(iFrameElem).getBody();
if (iFrameBody) {
  // do stuff
}
}