How to prevent events from being bound multiple times

Question

 $(\'.ajax\').click
 (        
    function()
    {
        // If been bound then we need to return here.
        alert(\':D\');
    }
 )

 $(\'.ajax\').click
 (
            


        

Answer 1

If using jQuery >= 1.7 you can use .on()/.off() API in conjunction with an event namespace. In this example .off() is called immediately to ensure previous events (of any kind) with the namespace are un-bound:

$("form")
    .off(".validator")
    .on("keypress.validator", "input[type='text']", validate);

It's quite a flexible API so you can be very specific if you need to be:

$("form")
    .off("keypress.validator", "input[type='text']", validate)
    .on("keypress.validator", "input[type='text']", validate);

The docs: http://api.jquery.com/off/