SOURCE CODE: Uize.Widget.Dialog.Iframe (view docs)

/*______________
|       ______  |   U I Z E    J A V A S C R I P T    F R A M E W O R K
|     /      /  |   ---------------------------------------------------
|    /    O /   |    MODULE : Uize.Widget.Dialog.Iframe Class
|   /    / /    |
|  /    / /  /| |    ONLINE : http://www.uize.com
| /____/ /__/_| | COPYRIGHT : (c)2006-2016 UIZE
|          /___ |   LICENSE : Available under MIT License or GNU General Public License
|_______________|             http://www.uize.com/license.html
*/

/* Module Meta Data
  type: Class
  importance: 4
  codeCompleteness: 100
  docCompleteness: 2
*/

/*?
  Introduction
    The =Uize.Widget.Dialog.Form= class extends its superclass with support for =iframe= dialogs, where the dialog's contents is a page loaded into an =iframe=.

    *DEVELOPERS:* `Chris van Rensburg`, `Jan Borgersen`
*/

Uize.module ({
  name:'Uize.Widget.Dialog.Iframe',
  builder:function (_superclass) {
    'use strict';

    return _superclass.subclass ({
      alphastructor:function () {
        var m = this;

        /*** initialization ***/
          function _setIframeUrl (_url) {
            if (_url != m._lastSetUrl) {
              m._lastSetUrl = _url;
              var _contentWindow = m.getContentWindow ();
              _contentWindow && _contentWindow.location
                ? _contentWindow.location.replace (_url)
                : (m.getNode ('content').src = _url)
              ;
            }
          }
          m.wire ({
            'Before Show':
              function () {_setIframeUrl (Uize.isFunction (m._url) ? m._url () : m._url)},
            'After Hide':
              function () {m._resetUrl && _setIframeUrl ('about:blank')}
          });
      },

      instanceMethods:{
        getContentWindow:function () {
          var _contentNode = this.getNode ('content');
          return _contentNode ? _contentNode.contentWindow : null;
        }
      },

      stateProperties:{
        _resetUrl:{
          name:'resetUrl',
          value:true
        },
        _url:{
          name:'url',
          value:'' /* QUESTION: is it really necessary to initialize this property to an empty string? */
        }
      }
    });
  }
});