Selector containing 'value' attribute causes deprecation warning

[wet]

Steps to reproduce:

0. Use jQuery 1.9-b1 and jQuery Migrate v1.0.0pre - 2012-12-17
1. Create a document containing <option> elements
2. Select some of these elements by their 'value' attribute

Result:

jQuery Migrate logs this console message:

JQMIGRATE: property-based jQuery.fn.attr('value') is deprecated

There's no occurence of jQuery.fn.attr in the userland code. It looks like jQuery uses jQuery.fn.attr internally to resolve the attribute selector.

Test case:

​http://jsfiddle.net/e2rgj/

[dmethvin]

Perhaps we can narrow the scope of this warning. Pre-1.9, in some situations we'd incorrectly use the property (the current value including stuff the user just typed in there) rather than the attribute (essentially, "what the HTML said").

Since your selector is $('body').find('option[value!=""]') there's no practical difference with an option between the property and the attribute. For input[type=text], textarea, and probably a few others can have the values diverge.

[dmethvin]

@gibson042 or @timmywil, thoughts?

[gibson042]

We could put together a whitelist and make the ​https://github.com/jquery/jquery-migrate/blob/master/src/attributes.js#L36 warning conditional.

[dmethvin]

Moved to ​https://github.com/jquery/jquery-migrate/issues/6

[dmethvin]

Closed in the jquery-migrate plugin, but this warning could still appear for a selector such as input[type=text][value=42] since the semantics of that selector have changed from looking at the property to looking at the value. I don't think that is a bad thing.

[timmywil]

I like the warning.