data() can be used as data[]

[marian]

I've noticed a strange behavior (I don't want to say it's a bug):

Normally, you use ​data this way:

>>> $('body').data('foo', 'bar')
[body.jq-enhanced]
>>> $('body').data('foo')
"bar"
>>> $('body > div').data('foo')
null

– everything's fine, other elements are not affected.

However if one uses it as follows, which is not that digressive IMHO (at least it was how I used it without thinking about it), everything seems also fine: …

>>> $('body').data['foo'] = 'bar'
"bar"
>>> $('body').data['foo']
"bar"

… until here:

>>> $('body > div').data['foo']
"bar"

As I said, I know this is not a bug, and I understand where the behavior comes from – all datas of all elements are the same object, and, well, [] does write on the object directly.

But nonetheless, I want to ask whether something can be done here to avoid this mistake, which is somehow self-evident and, I assume, made often. (It took me a looong time to find out that this was the reason :-) )

[dmethvin]

I'm not sure how we could prevent this. You're assigning values to properties of the data method. People have made similar mistakes like $("body").innerHTML = "hello"" that are also pretty difficult to detect. Ecmascript 5 will have the ability to seal objects to prevent new properties/methods from being assigned, but for now with existing browsers I don't see a solution.

[dmethvin]

No way we can fix this, unfortunately.