How to debug JavaScript / jQuery event bindings with Firebug or similar tools?

Question

I need to debug a web application that uses jQuery to do some fairly complex and messy DOM manipulation. At one point, some of the events that were bound to particular eleme

Answer 1

Here's a plugin which can list all event handlers for any given element/event:

$.fn.listHandlers = function(events, outputFunction) {
    return this.each(function(i){
        var elem = this,
            dEvents = $(this).data('events');
        if (!dEvents) {return;}
        $.each(dEvents, function(name, handler){
            if((new RegExp('^(' + (events === '*' ? '.+' : events.replace(',','|').replace(/^on/i,'')) + ')$' ,'i')).test(name)) {
               $.each(handler, function(i,handler){
                   outputFunction(elem, '\n' + i + ': [' + name + '] : ' + handler );
               });
           }
        });
    });
};

Use it like this:

// List all onclick handlers of all anchor elements:
$('a').listHandlers('onclick', console.info);

// List all handlers for all events of all elements:
$('*').listHandlers('*', console.info);

// Write a custom output function:
$('#whatever').listHandlers('click',function(element,data){
    $('body').prepend('
' + element.nodeName + ': 
' + data + '<\/pre>');
});


Src: (my blog) -> http://james.padolsey.com/javascript/debug-jquery-events-with-listhandlers/