在 Javascript 中访问所有事件侦听器

Question

I want to do something like this:

function('string', function2(){})

where I leave the to user to write what he wants in the string parameter and than execute function2 . The catch is here: string is an event listener. When the user writes click , I want to call onClick() , when the user writes mouse I want to call onMouseOver and so on.

I have in mind doing something with case , but how can I access all event listeners?

Answer 1

You should use addEventListener .

element.addEventListener("string", function() {}, false);

However, in the case of IE <= 8, you will need to use attachEvent as it does not follow the standard:

element.attachEvent("string", function() {});

Finally, as kybernetikos mentions in his comment, you can then use a simple dictionary to map mouse to mouseover .

If you wish to fire events, you should use dispatchEvent .

Answer 2

If you add the event listeners using the old model (ie elem.onclick = function(){ /* */ }; ), you can use

elem['on' + event]();

Keep in mind that this only fires the event listeners, but doesn't create an event (eg it won't bubble).

If you won't to create a event, which fires event listeners added using addEventlistener , and bubbles, and does all things a real event does, you must

1. Create your event using event constructors: Event or CustomEvent
2. Fire it with dispatchEvent

See MDN page for more information and examples.

Answer 3

you can use .trigger to do this. Check out this example in jsfiddle. type "dblclick" in the input box.

http://jsfiddle.net/jspatel/Suj4H/1/

<input id="writehere"> </input>
  $('#writehere').dblclick(function() {
     alert ('dblclick');
   });


$('#writehere').bind('keypress', function(e) {
    if(e.keyCode==13){
        $(this).trigger( $(this).val() );
    }
});