Side navigation
#9277 closed bug (wontfix)
Opened May 13, 2011 07:23PM UTC
Closed May 13, 2011 07:39PM UTC
'undefined' from .attr() causes potential breaking chaining issues in overload setter/getter
| Reported by: | mr.leon.yu@gmail.com | Owned by: | mr.leon.yu@gmail.com |
|---|---|---|---|
| Priority: | undecided | Milestone: | 1.next |
| Component: | attributes | Version: | 1.6.1 |
| Keywords: | Cc: | ||
| Blocked by: | Blocking: |
Description
With advent of jQuery 1.6, which returns undefined in .attr(), the occurrence of undefined in jQuery code has become ever more prevalent. This can cause a lot more existing code to break. The for example the following code:
$('element').attr('title', $('element2').attr('alt')).css('color', '#000');
In the above code, if $('element2').attr('alt') returns a value, the code would run fine. However, in 1.6, when $('element2').attr('alt') is undefined, the line would break because it would turn the setter call into an getter call. In turn the getter call would stop the chaining from working.
Solution:
Make sure arguments.length == 1 before assuming the call is a getter call.
Attachments (0)
Change History (3)
Changed May 13, 2011 07:29PM UTC by comment:1
| component: | unfiled → attributes |
|---|---|
| status: | new → open |
Changed May 13, 2011 07:35PM UTC by comment:2
| owner: | → mr.leon.yu@gmail.com |
|---|---|
| status: | open → pending |
I agree that this should be handled more like other user programming errors (quietly, discretely) but it still stands that if you know there is a possibility of that attr call returning undefined, you should be handling it in your own code. it's fixable with four characters:
$('element').attr('title', $('element2').attr('alt') || '' ).css('color', '#000');
Changed May 13, 2011 07:39PM UTC by comment:3
| resolution: | → wontfix |
|---|---|
| status: | pending → closed |
A further look at the history of the test suite reveals _many_ tests written to specifically support this expectation
Even before 1.6, the fact that a setter would act like a getter if the value you passed as the second argument was unexpectedly undefined was... unexpected and confusing to users. I concur with the OP that we should probably check arguments.length here.