W3C home > Mailing lists > Public > public-html@w3.org > June 2010

Re: Change proposal for ISSUE-85

From: Maciej Stachowiak <mjs@apple.com>
Date: Tue, 15 Jun 2010 19:30:46 -0700
Cc: Sam Ruby <rubys@intertwingly.net>, Steven Faulkner <faulkner.steve@gmail.com>, public-html@w3.org
Message-id: <6CE3E64B-D599-4D1D-BE6D-2118E46103D8@apple.com>
To: Ian Hickson <ian@hixie.ch>

On Jun 15, 2010, at 6:43 PM, Ian Hickson wrote:

> On Tue, 15 Jun 2010, Maciej Stachowiak wrote:
>> I think Sam's point was this: using href="javascript:" and the style="" 
>> attribute, one can make a link look and act like a button.
> You can do it with far less -- using just an external style sheet you can 
> turn any link into something having the appearance of a button.

The href="javascript:..." issue is relevant because it can make the *behavior* like a button, and indeed almost always does. 

>> The spec makes this valid
> No, doing so is invalid. The spec says:
> # Authors must not use elements, attributes, or attribute values for 
> # purposes other than their appropriate intended semantic purpose.

However, a validator will not flag this error.

>> I the case of href="javascript:..." in particular, it seems to me that 
>> pretty much any time that is present on a link, the link is essentially 
>> acting as a button rather than as a link.
> Note that in the context of ARIA, we're not talking about whether a link 
> should have been better presented as a button, but about what it should be 
> exposed as in ATs. Consider the links on reddit:
>   http://www.reddit.com/
> From an AT perspective, the "Submit a link" and "Create your own reddit" 
> <a> elements are buttons, and are non-conforming (they should use <input> 
> or <button>).

That seems wrong to me. They both act as links, even though they have an appearance that may resemble buttons. They show a URL in the status bar when hovered, and take the user to that page when clicked, through a straightforward application of <a href>. It seems to me <a> is being used for the intended semantic purpose, even if styled in a superficially button-like way. It is proper for these page elements to show a URL in the status bar, show the link cursor when hovered, and be recognized as links by search engines. It would be semantically inferior to mark them up as <input> or <button> elements, since then the previously mentioned properties would not hold.

> The "share" <a> elements below the headlines are links.

How are the "share" elements links? They don't have the styling of a button, true, but when clicked they do not perform a navigation, rather they perform a command. It is inappropriate that this element shows a link cursor, shows "#" in the status bar when hovered, and is seen by the search engine as a link, since it does not link to anything.

Are you arguing that the semantics of being a button or link are based solely on appearance and not at all on behavior? That does not match my understanding of the word "semantics". I think I may be completely failing to understand what you think makes the semantic distinction between a button and a link. I would appreciate if you could explain it. Perhaps the explanation should go in the Change Proposal.

> The arrow <div>s are buttons (and should probably use <input type=image> for 
> optimal accessibility). It would be wrong to have the "share" links be 
> marked up as buttons using ARIA, because then the ATs would report them as 
> something different than what they actually are. Links and buttons are 
> widgets that form part of platform widget libraries. You don't see native 
> applications reporting link widgets as buttons to ATs. Why would we?

Native applications using most native accessibility APIs can report anything they like as a button or link. 

>> However, the spec currently makes javascript: URLs conforming.
> The spec doesn't make javascript: URLs conforming.

Are you saying that the spec makes javascript: URLs nonconforming, or that there an html document can be in some third state besides "conforming" and "nonconforming"?

> The only author-facing 
> mention of the javascript: scheme is in a non-normative introductory 
> statement that takes no position on the scheme. The UA-facing mentions are 
> all similarly neutral on the scheme and merely explain how the scheme 
> should work for interoperability purposes. One mention even refers to its 
> behaviour as being required merely for historical purposes.
> Incidentally, the one example mentioning javascript: refers to the 
> resulting UI as a link, not as a button.
>> On the surface, it seems inconsistent to allow a feature that can be 
>> used in almost no other way than to make a button act as a link, but at 
>> the same time forbid applying ARIA markup to tell AT that it is a 
>> button.
> The whole point of forbidding the misuse of ARIA here is to discourage the 
> use of links as buttons, as described both by the change proposal and by 
> the text of the spec, which explicitly encourages validators to say this. 
> It even uses the link/button case as the explicit example:
> # Conformance checkers are encouraged to phrase errors such that authors 
> # are encouraged to use more appropriate elements rather than remove 
> # accessibility annotations. For example, if an a element is marked as 
> # having the button role, a conformance checker could say "Either a button 
> # element or an input element is required when using the button role" 
> # rather than "The button role cannot be used with a elements".
>> I must admit I personally hadn't thought about this issue in evaluating 
>> the ARIA roles allowed by the HTML5 spec. It seems like consistency 
>> would call for either disallowing links to javascript: URLs (or likewise 
>> links to href="#" with mouse event handlers), or allowing such links to 
>> carry role="button". I don't have a strong opinion on this issue, but 
>> there is a good argument to be made that the current spec is 
>> inconsistent.
> As far as I can tell the spec is consistent here.
> Note that it is possible to use javascript: and <a> for what is 
> legitimately a link (e.g. trivially using window.open()).

Would you agree that the vast majority of uses are not legitimately a link? 

> It's unclear to me how to update my change proposal with the above. The 
> arguments above are arguing against a misunderstanding of the current 
> spec. Does this e-mail correct the misunderstandings sufficiently that the 
> chairs will base their decisions on a correct understanding of the spec, 
> or should the change proposal be updated to also argue against these 
> misunderstandings? I don't really understand the right way to proceed.

>From your reddit examples, it's clear that your understanding of button and link semantics is not the same as mine. I think it is uncharitable to call either understanding a "misunderstanding" until we are each clear on what the other's understanding is.

To be clear: I believe the semantics of a link are that it navigates the user to a different page. The semantics of a button are that it performs a command. Appearance is irrelevant to the semantics. By this understanding, I would draw the exact opposite conclusion on what is or is not a button or link in the reddit examples you gave. I would like to hear how your understanding differs before commenting further.

Received on Wednesday, 16 June 2010 02:31:51 UTC

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