jQuery.iframe.js,simple jQuery plugin for iframe element

jQuery.iframe.js

/**
 * Simple jQuery plugin for iframe element .
 * 
 * Note: The parent doc and iframe's embed doc must be in the same origin , 
 * Domains, protocols and ports must match.
 * 
 * reference:
 * 	https://developer.mozilla.org/en-US/docs/Web/JavaScript/Same_origin_policy_for_JavaScript
 * 	https://developer.mozilla.org/en-US/docs/Web/HTML/Element/iframe
 * 
 * @author manjun.han
 * @date 2014.3.8
 */
(function($){
	
	/**
	 * determine if the dom contained in jQuery wapper object is HTMLIFrameElement.
	 * 
	 * @param {Object} The jQuery wapper object
	 * @return {Boolean} true,the dom is HTMLIFrameElement  
	 */
	function validateIframe($el){
		if($el.length == 0 || $el[0].nodeName.toLowerCase() != 'iframe'){
			return false ;
		}
		return true ;
	}
	
	/**
	 * Get the window object of the HTML doc embed in iframe.
	 * 
	 * @return {Object} window object of embed HTML doc.
	 */
	$.fn.iframeWin = function(){						
		return validateIframe(this) ? this[0].contentWindow : null ;
	};							
	
	/**
	 * Get the document object of the HTML doc embed in iframe.
	 * 
	 * @return {Object} document object of embed HTML doc.
	 */
	$.fn.iframeDoc = function(){
		return validateIframe(this) ?  (this[0].contentDocument || this[0].contentWindow.document) : null ;
	};	
	
	/**
	 * Set the selected iframe element's height to its content doc's height.
	 *  
	 * @return jQuery wapper object.
	 */
	$.fn.iframeAutoHeight = function(){
		
		this.each(function(index , el){
			
			var $el = $(el) ;
			
			if(!validateIframe($el)){
				return ;
			}
			
			var loaded = $el.data("iframe-loaded");
			
			if(loaded){						
				 $el.css("height" , $($el.iframeDoc()).height()+"px");
			}else{
				$el.bind("load" , function(){
					$el.data("iframe-loaded" , true).iframeAutoHeight();
				});
			}
		});
		
		return this ;
	};
	
})($);