Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
254 views
in Technique[技术] by (71.8m points)

javascript - Is there a standard for the event order of click and change on a checkbox?

I've noticed that the order of 'click' and 'change' events are different in Chrome and Firefox.

See this JSFiddle for example: http://jsfiddle.net/5jz2g/3/

JavaScript:

var el = $('foo');
var fn = function(e) {
    console.log(e.type);
}
el.addEvent('change', fn);
el.addEvent('click', fn);

In Chrome this logs:

change
click

And in Firefox this logs:

click
change

Is there a standard for the order of events? Which should fire first? The MDN doesn't seem to mention this and I couldn't find a thing about this in the W3C documents.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

DOM3 Events document has a recommendation about events order. According to it, in case of checkbox, the correct order will be click then change and not vice versa, because change event obviously is a part of default actions for checkbox, see Example 5 and fiddle, which works as expected in FF but not in Chrome. That's logical, anyway. But! Let's read default actions section carefully:

Default actions should be performed after the event dispatch has been completed, but in exceptional cases may also be performed immediately before the event is dispatched.

Did you see that? W3C uses RFC's words SHOULD and MAY in one sentence! Nothing to be done, they're cautious guys. IMO, that's why we have what we have :)


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...