1.4/1.4.1 and 1.4.2+ compatible event special .add method

jquery.event.special.foo.add.js

// 1.4.2
$.event.special.foo = {
  
  add: function( handleObj ) {
    // Do something when event is bound here!
    
    // Modify event object here!
    var old_handler = handleObj.handler;
    handleObj.handler = function(event) {
      // handleObj.type (string)
      // handleObj.data (anything)
      // handleObj.namespace (string.dot.separated)
      old_handler.apply( this, arguments );
    };
  }
  
};

// 1.4, 1.4.1
$.event.special.foo = {
  
  add: function( handler, data, namespaces ) {
    // Do something when event is bound here!
    
    // Modify event object here!
    return function(event) {
      // handler.type (string, needs to be massaged to be useful)
      // data (anything)
      // namespaces (sorted array)
      handler.apply( this, arguments );
    };
  }
  
};

// 1.4, 1.4.1 and 1.4.2
$.event.special.foo = {
  
  add: function( handleObj, data, namespaces ) {
    // Do something when event is bound here!
    
    var old_handler;
    
    // Modify event object here!
    function new_handler(e) {
      // handleObj.type (string)
      // handleObj.data (anything)
      // handleObj.namespace (string.dot.separated)
      old_handler.apply( this, arguments );
    };
    
    // This may seem a little complicated, but it normalizes the special event
    // .add method between jQuery 1.4/1.4.1 and 1.4.2+
    if ( $.isFunction( handleObj ) ) {
      // 1.4, 1.4.1
      old_handler = handleObj;
      handleObj = {
        type: old_handler.type.split('.')[0],
        data: data,
        namespace: namespaces.join('.')
      };
      return new_handler;
    } else {
      // 1.4.2+
      old_handler = handleObj.handler;
      handleObj.handler = new_handler;
    }
  }
  
};