On 11 Dec 2013, at 18:40, Bryan Davis bd808@wikimedia.org wrote:

On Wed, Dec 11, 2013 at 9:59 AM, Sen kik888@gmail.com wrote:

...

when i open the chrome console,i always can get:

...

event.returnValue is deprecated. Please use the standard event.preventDefault() instead.

is any plan to fix this?

I don't know if there is currently a plan to fix it, but the warning is from jQuery and should be fixed by version 1.11 or greater [0]. As noted on the upstream bug this is just a warning and should have no effect on functionality.

In addition to merely being deprecated (and us using a dated version of jQuery), it is also harmless if support were to be removed entirely by Chrome.

As far as I know, no version of jQuery ever relied on event.returnValue. It just did the fallback from the standard event.preventDefault in an odd way causing it to trigger a property access, which then (now, years later) got triggered by Chrome’s deprecation system.

Simplified:

* They were using (jQuery v1.9.1):

e.defaultPrevented || e.returnValue === false

Which means if the browser supports standard e.defaultPrevented, but is genuinely set to false (it is a boolean property after all) it would look at e.returnValue.

* They are now using (jQuery v1.11.0-pre, latest upstream master):

e.defaultPrevented ( … ) e.defaultPrevented === undefined && e.returnValue === false

-- Krinkle