There have been many method additions and deprecations in the last jQuery releases, but never so many changes that remove previous deprecations and make backward incompatible changes in a single release. Final release of jQuery 1.9 will be announced today. This article will help you get an overview of what’s changing and how to get prepared. So lets review these changes.
1) $.browser is no longer available
$.browser added in v1.0, deprecated since v1.3 and now it's gone. If possible use browser feature detection ($.support) instead of browser sniffing ($.browser). The documentation says that it may be moved to a plugin, but it's not yet (well, not considering jQuery Migrate of course). If you haven't used $.support before, we will cover it in our next post.
For those who really need just the browser sniffing feature back, you can copy-paste the highlighted code from jQuery 1.8.3's core here.
2) .andSelf() is renamed to .addBack()
.andSelf() added in v1.2, deprecated in v1.8. It's used for adding previous selection set to the current set in the chain.
For example: $('.first-set').children().andSelf() - would return a set with all children of the .first-set, plus .first-set's themselves. It took no arguments and now it has been replaced by .addBack() method that does the exact same thing, but accepts optional selector argument to filter out the set. So with the example above you could say: $('.first-set').children().addBack('div') - return all children of .first-set, plus .first-set's that are <div>s.
3) Removed deprecated .sub()
.sub() added in v1.5, deprecated in v1.7. Lets you create a copy of jQuery object, so that methods' default behaviours could be overwritten.
For example you could overwrite jQuery's .data() methods so that it would try to fetch required data from your server if it's not found on the element.
(function() {
var copy = jQuery.sub();
copy.data = function(element, key, value) {
// Make sure user is trying to get, not set data
if(!!value) return jQuery.data.apply(this, arguments);
// Get data using default jQuery.data() method
var data = jQuery.data.apply(this, arguments);
if(!data) {
// if no data, get it from the server
data = $.ajax({ AJAX_INFO });
}
// Once we have the data, cache it using
// original $.data() and return to the callee
return jQuery.data.apply(this, arguments, data);
};
copy(document).ready(function($) {
alert($(".test-elem").data();
});
})();
If you want to study how it was accomplished, here is the related code from 1.8.3 code base.
4) Can't toggle through click events, only visibility
.toggle() added in v1.0, deprecated in v1.8. There were 2 .toggle() methods: one that animates show/hide, the other toggles click events. The one that toggles through click handlers is removed. So .toggle(function(){}, function(){}) will not work. Here is the related code in jQuery Migrate plugin.
5) No more $('img').error()
.error() added in v1.0, deprecated in v1.8. Not to be confused with $.error() method, that throws new Error(msg);
6) .attr() for working with attributes only
.attr('value', newValue) used to set property instead of attribute. To set current value use .prop('value', newValue) and .val(newValue) for form elements.
Learn the difference between property and attribute.
7) Removed "hover" pseudo-event
"hover" – there is no more event called hover. Instead use "mouseenter mouseleave". Please note, that only pseudo-event name is no longer available. You can still use .hover() method.
8) Global AJAX events triggered on document
ajaxStart, ajaxSend, ajaxSuccess, ajaxError, ajaxComplete, ajaxStop now must be bound to 'document'.
9) Internal undocumented changes
There are also some other internal methods that were either changed or removed (like .data('events') and $.clean()), but since they are not documented I guess you are not using them.
How to deal with all the changes?
As you can see jQuery 1.9 throws away many deprecated methods, but the team understands that there is a lot of code in production that relies on these features. So jQuery team provided us with jQuery Migrate plugin that makes code written prior to 1.9 work with it.
If you use unminified version of the plugin, it will log warning messages in console if your code uses any of the deprecated methods. The minified file is for production and it does not throw any warnings.