Old stuff here.. use jQuery BBQ instead!

precursor-to-bbq.js

// The oldest predecessor to jQuery BBQ I can find in my archives.
// http://benalman.com/projects/jquery-bbq-plugin/
// http://benalman.com/news/2010/04/cooking-bbq-the-original-recipe/
 
/* == QUERY STRING ==
  
  USAGE:
 
  var foo = QueryString();
  * returns data Object from document.location.search
  
  var foo = QueryString( { a:1, b:2 } );
  * returns serialized '?a=1&b=2' string
  
  var foo = QueryString( '?a=1&b=2' );
  * returns deserialized { a:1, b:2 } object
  
  var foo = QueryString( '/foo?a=0&c=3', { a:1, b:2 } );
  * returns '/foo?a=1&c=3&b=2' url
 
  var foo = QueryString( '/foo?a=0&c=3', '?a=1&b=2' );
  * returns '/foo?a=1&c=3&b=2' url
  
*/
 
function QueryString(arg1, arg2, arg3) {
  
  var serialize = function(obj) {
    var qs = [];
    for (var n in obj) {
      if (obj[n] != undefined) {
        v = obj[n];
        if (typeof v != 'object') {
          v = [v];
        }
        for (var i = 0; i < v.length; i++) {
          if (v[i] == '') {
            qs.push(encodeURIComponent(n));
          } else {
            qs.push(encodeURIComponent(n) + '=' + encodeURIComponent(v[i]));
          }
        }
      }
    }
    return qs.length ? ('?' + qs.join('&')) : '';
  }
  
  var deserialize = function(str, convert_to_number) {
    str = str.replace(/^[^?]*([?]|$)/, '');
    if (str == '') return {};
    var qs = str.split('&');
    var obj = {};
    for (var i = 0; i < qs.length; i++) {
      var nv = qs[i].split('=');
      var n = decodeURIComponent(nv[0]);
      if (nv.length == 1) {
        obj[n] = '';
      } else {
        var v = decodeURIComponent(nv[1]);
        v = convert_to_number && !isNaN(v) ? Number(v) : v;
        if (typeof obj[n] == 'object') {
          obj[n].push(v);
        } else if (typeof obj[n] != 'undefined') {
          obj[n] = [obj[n], v];
        } else {
          obj[n] = v;
        }
      }
    }
    return obj;
  }
  
  var build_url = function(url, obj, mode) {
    // mode: 0 = update url qs with obj (passed obj overrides)
    //       1 = update url qs with obj (url qs overrides)
    //       2 = completely replace url qs with obj
    
    var url_qs = deserialize(url);
    
    if (typeof obj == 'string') {
      obj = deserialize(obj);
    }
    
    var qs;
    if (mode == 2) {
      qs = obj;
    } else if (mode == 1) {
      for (var prop in url_qs) {
        obj[prop] = url_qs[prop];
      }
      qs = obj;
    } else {
      for (var prop in obj) {
        url_qs[prop] = obj[prop];
      }
      qs = url_qs;
    }
    
    var qs_str = serialize(qs);
    if (qs_str != '') {
      url = url.replace(/[?].*$/, '');
      return url + qs_str;
    } else {
      return url;
    }
  }
  
  if (typeof arg1 == 'string' && arg2 != undefined) {
    return build_url(arg1, arg2, arg3);
    
  } else if (typeof arg1 == 'object') {
    return serialize(arg1);
    
  } else if (typeof arg1 == 'string') {
    return deserialize(arg1);
    
  } else {
    return deserialize(document.location.search);
  }
}