1267356 - hidden property associated to HTMLElement is not working as expected

Status: RESOLVED INVALID

(Core :: DOM: Core & HTML, defect)

Description

[devan.shah14]

Attachment: hiddenPropertyPickingUpSomethingElse.html

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Firefox/45.0
Build ID: 20160411140819

Steps to reproduce:

Running Javascript "document.getElementById("formHiddenSomeHow").hidden" on one of the elements on my page, this form element contains an element under it which has id="hidden". Attached is a sample webpage.


Actual results:

When I execute the above javascript on this page it is not returning a boolean but instead it is returning my element which has the id="hidden". (In the case I have multiple elements which have hidden id, it returns a Radio list of those elements.


Expected results:

I expected it to return a boolean true or false if the element is hidden or not, which is what the https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement specs say that the HTMLElement.hidden is to be used for.

Comment 1

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

I'm afraid <https://html.spec.whatwg.org/multipage/#the-form-element> shows that the HTMLFormElement interface has the OverrideBuiltins extended attribute, which implies this behaviour: <http://heycam.github.io/webidl/#OverrideBuiltins>.

INVALID per spec; you could try to get the spec changed, though I doubt you'd succeed.

Comment 2

[devan.shah14]

The same issue exists even if you change the parent from form element to div element and according to https://html.spec.whatwg.org/multipage/semantics.html#the-div-element div does not have the OverrideBuiltins. 

But why would the OverrideBuiltins affect id="hidden" context, hidden in this case is only being used as a string context and nothing else.

Comment 3

[devan.shah14]

ignore the previous comment, it does not happen for div, only happens for div if there is a form element embedded under div

Comment 4

[devan.shah14]

But in general why would id="hidden" OverrideBuiltins override the FormElement.hidden, to return that element instead of boolean. In this context hidden is a string context and nothing more. or is that not the case.

So in the case that I have something like the following:
        <form hidden id="formHiddenSomeHow">
            <input id="hidden">
        </form>
My form is hidden but when i do document.getElementById("formHiddenSomeHow").hidden it does not return if it is hidden or not. I can check it as an attribute, but in the case that the hidden is added with javascript it will not show up as attribute.

Comment 5

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

form elements have a getter that exposes elements by ID as properties on the element: https://html.spec.whatwg.org/multipage/forms.html#dom-form-nameditem

Comment 6

[devan.shah14]

thanks