In my project I am currently using some custom data-* attributes in my HTML to convey some extra data that will be used by jQuery. I found the .data()
method and noticed that if I have a data-* attribute data-my-attribute
that I can retrieve its value in jQuery by selecting the element with the attribute and calling .data("my-attribute")
.
I assumed that this was the way it is supposed to be used (did not look into the documentation) and used it through out my jQuery code. However, now I noticed that when I put for example a string "000005643"
in the HTML data-* attribute, .data("my-attribute")
return 5643
while .attr("data-my-attribute")
return "000005643"
. Where the latter is what I wanted. This led me to look up the documentation and actually found out that there is more to .data()
than I thought. Also, I never saw any text or example that indicates you should use .data()
to retrieve values of data-* attributes. This worries me that I am doing something fundamentally wrong.
So should I cease and desist with using .data()
in this manner or not? If not, could you开发者_运维百科 link me to some documentation about the .data()
function that explains this use.
The data()
method returning HTML5 data-*
attributes was introduced in 1.4.3.
As of jQuery 1.4.3 HTML 5 data- attributes will be automatically pulled in to jQuery's data object.
Every attempt is made to convert the string to a JavaScript value (this includes booleans, numbers, objects, arrays, and null) otherwise it is left as a string. To retrieve the value's attribute as a string without any attempt to convert it, use the attr() method.
Source.
It appears jQuery is certain you want a number, so it is returning a Number
for you, not the String
.
If you want it as a string, use attr()
.
I'm actually working on porting this functionality to Zepto. Yeah, it's not really something wrong with the data- HTML spec but it's just jQuery's implementation of it. It's trying to work around the fact that data- doesn't handle non-strings very well and then it tries to be fancy and pull out values like null, ints, and floats for you. I suppose a workaround is putting a string character in front of your value and substr'ing it off when you retrieve it. Either that or use attr('data-') - though going back and forth between .data and .attr could lead to different results as you've noticed. Stick with one or the other.
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