jQuery Query Plugin

jquery.query.js

/**
 * jQuery Query Plugin by M. Pezzi
 * Version: 1.0 (08/25/11)
 * https://gist.github.com/1170858
 * Dual licensed under the MIT and GPL licences:
 * http://www.opensource.org/licenses/mit-license.php
 * http://www.gnu.org/licenses/gpl.html
 * Requires: jQuery v1.4.2 or later
 */
(function($){
  
  $.query = function(key, value) {
    var e, a = /\+/g, r = /([^&=]+)=?([^&]*)/g,
        d = function (s) { return decodeURIComponent(s.replace(a, " ")); },
        q = window.location.search.substring(1),
        urlParams = {};
    
    while ( e = r.exec(q) )
      urlParams[d(e[1])] = d(e[2]);
    
    if ( typeof key !== 'undefined' && typeof value == 'undefined' ) {
      return urlParams[key];
    } else if ( typeof key !== 'undefined' && typeof value !== 'undefined' ) {
      return ( urlParams[key] == value );
    } else {
      return urlParams;
    }
  };
  
})(jQuery);