jQuery special events

Custom click event: clickDisabled http://benalman.com/news/2010/03/jquery-special-events/

HTML

<h1>
    <a href="http://benalman.com/news/2010/03/jquery-special-events/" target="_top">jQuery special events</a>
    &raquo; Custom click event: clickDisabled
</h1>

<p class="intro">(click box and links)</p>

<div id="test">
    <div id="a">
        a
        <br/>
        <a href="#foo" id="foo">foo</a>
        <a href="#bar" id="bar">bar</a>
        <a href="#baz" id="baz">baz</a>
    </div>
</div>

<div id="nav">
    <a href="#">cycle through sample $.clickDisabled selectors</a>
</div>

<div id="status"></div>
<div id="log"></div>

CSS

body { font-family: Arial, Helvetica, sans-serif; font-size: 0.8em; }
h1 { font-weight: 700; font-family: "Gill Sans", "Gill Sans MT", Arial, Helvetica, sans-serif; }
h1, a { color: #913D00; }
a:hover { color: #FF7F00; }
h1 { font-size: 120%; margin-bottom: 0.6em; }
.intro { font-style: italic; margin-top: 0.5em; }

#test, #nav, #status, #log {
    margin-top: 1em;
}

#test div {
    border: 1px solid #000;
    margin: 1em 0;
    padding: 0.5em 1em;
}

JavaScript

$(function(){
    function log(){
        $('#log').append([].join.call(arguments,', ')+'<br/>');
    };
    
    var i = 0,
        state = 0,
        states = [
            { selector: null, text: 'Nothing disabled.' },
            { selector: '#test a', text: 'Click disabled on A elements.' },
            { selector: '#test *', text: 'Click disabled on everything.' }
        ];
    
    // Bind the click event to the links as well as parent div
    // so we can see the event propagate.
    $('#test *').click(function(){
        log( ++i, '#' + this.id + ' clicked' );
    });
    
    // Cycle through sample $.clickDisabled selectors
    $('#nav a').click(function(){
        $.clickDisabled = states[ ++state % states.length ].selector;
        return false;
    });
    
    // Keep the log output updated.
    setInterval(function(){
        $('#status').html( [ states[ state % states.length ].text,
                        '$.clickDisabled: ' + $.clickDisabled,
                        'Current URL: ' + location.href ].join('<br/>') );
    },100);
});

//////////////////////////////////////////////////
// THE FOLLOWING CODE IS TAKEN FROM THE EXAMPLE //
//////////////////////////////////////////////////

(function($){
  
  // A public property that can be changed at any time.
  $.clickDisabled = null;
  
  // Special event definition.
  $.event.special.click = {
    add: function( handleObj ) {
      // Save a reference to the bound event handler.
      var old_handler = handleObj.handler,
        
        // The current element.
        elem = $(this);
      
      handleObj.handler = function( event ) {
        if ( $.clickDisabled && elem.is( $.clickDisabled ) ) {
          // If $.clickDisabled is specified and the element to which the
          // callback is bound matches the specified selector, prevent the
          // default action without stopping propagation, and don't call
          // the originally bound event handler.
         ...