What's the difference between `on` and `live` or `bind`?

Question

In jQuery v1.7 a new method, on was added. From the documentation:

‘The .on() method attaches event handlers to the currently se

Answer 1

on is in nature very close to delegate. So why not use delegate? It's because on doesn't come alone. there's off, to unbind event and one to create an event to be executed one time only. This is a new event's "package".

The main problem of live is that it attaches to "window", forcing a click event (or other event) on an element deep inside the page structure (the dom), to "bubble up" to the top of the page to find an event handler willing to deal with it. At each level, all event handlers have to be checked, this can add up fast, if you do deep imbrication (

etc etc etc...) So, bind, like click, like other shortcut event binders attach directly to the event target. If you have a table of, let's say, 1000 lines and 100 columns, and each of the 100'000 cells includes a checkbox which click you want to handle. Attaching 100'000 event handlers will take a lot of time on page load. Creating a single event at the table level, and using event delegation is several orders of magnitude more efficient. The event target will be retrieved at event execution time. "this" will be the table, but "event.target" will be your usual "this" in a click function. Now the nice thing with on is that "this" will always be the event target, and not the container it is attached to. 0 讨论(0) 查看其它7个回答 发布评论: 提交评论  加载中... 验证码  看不清? 提交回复 热议问题