jQuery 1.9 .live() is not a function

Forward port of .live() for jQuery >= 1.9 Avoids refactoring JS dependencies on .live() Uses optimized DOM selector context 

/** 
 * Forward port jQuery.live()
 * Wrapper for newer jQuery.on()
 * Uses optimized selector context 
 * Only add if live() not already existing.
*/
if (typeof jQuery.fn.live == 'undefined' || !(jQuery.isFunction(jQuery.fn.live))) {
  jQuery.fn.extend({
      live: function (event, callback) {
         if (this.selector) {
              jQuery(document).on(event, this.selector, callback);
          }
      }
  });
}

You can avoid refactoring your code by including the following JavaScript code 

jQuery.fn.extend({
    live: function (event, callback) {
       if (this.selector) {
            jQuery(document).on(event, this.selector, callback);
        }
        return this;
    }
});

The jQuery API documentation lists live() as deprecated as of version 1.7 and removed as of version 1.9: link.

version deprecated: 1.7, removed: 1.9

Furthermore it states:

As of jQuery 1.7, the .live() method is deprecated. Use .on() to attach event handlers. Users of older versions of jQuery should use .delegate() in preference to .live()


jQuery .live() has been removed in version 1.9 onwards

That means if you are upgrading from version 1.8 and earlier, you will notice things breaking if you do not follow the migration guide below. You must not simply replace .live() with .on()!

Read before you start doing a search and replace:

For quick/hot fixes on a live site, do not just replace the function live with on,
as the parameters are different!

.live(events, function)

should map to:

.on(eventType, selector, function)

The (child) selector is very important! If you do not need to use this for any reason, set it to null.

Migration Example 1:

before:

$('#mainmenu a').live('click', function)

after, you move the child element (a) to the .on() selector:

$('#mainmenu').on('click', 'a', function)

Migration Example 2:

before:

$('.myButton').live('click', function)

after, you move the element .myButton to the .on() selector, and find the nearest parent element (preferably with an ID):

$('#parentElement').on('click', '.myButton', function)

If you do not know what to put as the parent, document always works:

$(document).on('click', '.myButton', function)

See also:

  • jQuery - how to use the “on()” method instead of “live()”?
  • jQuery 1.9 Migration Guide

Tags:

Javascript

Function

Jquery

Deprecated

Live

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