jquery.getUrlParam.js

/* Copyright (c) 2006-2007 Mathias Bank (http://www.mathias-bank.de)
 * Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php) 
 * and GPL (http://www.opensource.org/licenses/gpl-license.php) licenses.
 * 
 * Version 2.1
 * 
 * Thanks to 
 * Hinnerk Ruemenapf - http://hinnerk.ruemenapf.de/ for bug reporting and fixing.
 * Tom Leonard for some improvements
 * 
 */
jQuery.fn.extend({
/**
* Returns get parameters.
*
* If the desired param does not exist, null will be returned
*
* To get the document params:
* @example value = $(document).getUrlParam("paramName");
* 
* To get the params of a html-attribut (uses src attribute)
* @example value = $('#imgLink').getUrlParam("paramName");
*/ 
 getUrlParam: function(strParamName){
	  strParamName = escape(unescape(strParamName));
	  
	  var returnVal = new Array();
	  var qString = null;
	  
	  if ($(this).attr("nodeName")=="#document") {
	  	//document-handler
		
		if (window.location.search.search(strParamName) > -1 ){
			
			qString = window.location.search.substr(1,window.location.search.length).split("&");
		}
			
	  } else if ($(this).attr("src")!="undefined") {
	  	
	  	var strHref = $(this).attr("src")
	  	if ( strHref.indexOf("?") > -1 ){
	    	var strQueryString = strHref.substr(strHref.indexOf("?")+1);
	  		qString = strQueryString.split("&");
	  	}
	  } else if ($(this).attr("href")!="undefined") {
	  	
	  	var strHref = $(this).attr("href")
	  	if ( strHref.indexOf("?") > -1 ){
	    	var strQueryString = strHref.substr(strHref.indexOf("?")+1);
	  		qString = strQueryString.split("&");
	  	}
	  } else {
	  	return null;
	  }
	  	
	  
	  if (qString==null) return null;
	  
	  
	  for (var i=0;i<qString.length; i++){
			if (escape(unescape(qString[i].split("=")[0])) == strParamName){
				returnVal.push(qString[i].split("=")[1]);
			}
			
	  }
	  
	  
	  if (returnVal.length==0) return null;
	  else if (returnVal.length==1) return returnVal[0];
	  else return returnVal;
	}
});