getData/setData/changeData events need tech review and docs

[dmethvin]

The data events have unusual behavior and are currently not documented at api.jquery.com.

See these forum threads:

​http://forum.jquery.com/topic/jquery-fn-data-get-set-changedata-events-syntax

​http://forum.jquery.com/topic/setdata-getdata-events-should-be-capable-of-overriding-data-s-default-behavior-but-how

[snover]

#7573 is a duplicate of this ticket.

[snover]

I think they should be removed. They are slow, inconsistent to other events, and could be duck punched in by anyone that needs them.

[jitter]

I'm not totally against removing them. We should bring this on for the 1.6 roadmap, maybe deprecate for 1.6/1.7 and then sometime remove'em + compat plugin.

In the meantime I propose something like ​this to speed up $.fn.data. This way $.fn.data would only be 2x-3x slower then $.data if no one listens to the data-events.

[john]

Since we've decided to keep the events, I'm closing this and adding the needsdocs keyword so that we can tackle that later.

[addyosmani]

Having spoken to Dave and Karl regarding this, there appear to be some oppositions to us documenting these methods at the moment. I'll be removing the needsdocs tag until a point where we decide to document them again.

[denver.root@…]

To anyone who might be concerned with my opinion: In the release notes for 1.4.3 you noted changes to two of these functions, and introduced the third. I am positive that these are useful functions, but the utter lack of documentation limits their adoption, and honestly, ambiguates "your" official position on whether or not anyone should use them. In our communities, as you well know, when a feature is undocumented, we tend to avoid it, even when it proves to be incredibly useful, because we don't want to introduce regressions later when the feature unexpectedly disappears...

From one programmer to another, please either document these features, or remove them, so it's not ambiguous to all of us out here whether or not they will be dependable. I'd much rather just write a plugin to do this same thing, but don't want to duplicate your work if it's sticking around...

Thanks :)

(you're doing a great job)