Accessing functions bound to event handlers with jQuery

问题

With jQuery you can bind functions to an event triggered on a DOM object using .bind() or one of the event handler helper functions.

jQuery have to store this internally somehow and I wonder if is it possible given a DOM object, to find out which events have been bound to the object, and access those functions etc. The desired return result could look something like this:

{
  click: [function1, function2],
  change: [function3],
  blur: [function4, function5, function6]
}

回答1:

Edit: the method below works only in jQuery < 1.7

You can find a lot of interesting tips and tricks in this article: Things you may not know about jQuery.

It seems that jQuery uses data to store event handlers:

You can access all event handlers bound to an element (or any object) through jQuery’s event storage:

// List bound events:
console.dir( jQuery('#elem').data('events') );

// Log ALL handlers for ALL events:
jQuery.each($('#elem').data('events'), function(i, event){
    jQuery.each(event, function(i, handler){
        console.log( handler['handler'].toString() );
    });
});

// You can see the actual functions which will occur
// on certain events; great for debugging!

回答2:

jQuery 1.7 has stopped exposing the events in the regular data() function. You can still get them like this:

var elem = $('#someid')[0];
var data = jQuery.hasData( elem ) && jQuery._data( elem );
console.log(data.events);

Please note, that this only works for Events which have been bound using jQuery. AFAIK you there is no way to see all the events which have been bound using the regular DOM functions like addEventListener.

You can see them in the webkit inspector though: In the Elements tab navigate to the desired DOM node, on the right side select the "Event Listeners" drop down.

来源：https://stackoverflow.com/questions/2388030/accessing-functions-bound-to-event-handlers-with-jquery