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Re: Change proposal for ISSUE-85

From: Maciej Stachowiak <mjs@apple.com>
Date: Tue, 15 Jun 2010 21:37:46 -0700
Cc: Ian Hickson <ian@hixie.ch>, Sam Ruby <rubys@intertwingly.net>, Steven Faulkner <faulkner.steve@gmail.com>, public-html@w3.org
Message-id: <8B5C0E74-3A6E-4285-A705-7CDA1A14C6A6@apple.com>
To: Maciej Stachowiak <mjs@apple.com>

Ian and I discussed this topic on IRC and I believe we ended up on roughly the same page about the semantics of buttons and links, how this applies to reddit, and how that is relevant to techniques like javascript: URLs or links with onclick attributes. I see that Ian has updated his Change Proposal, but in case anyone would like to see the discussion, you can see the conversation from 04:33 tp 05:08 here.

http://krijnhoetmer.nl/irc-logs/whatwg/20100616#l-158

Regards,
Maciej


On Jun 15, 2010, at 7:30 PM, Maciej Stachowiak wrote:

> 
> 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.
> 
> Regards,
> Maciej
> 
> 
Received on Wednesday, 16 June 2010 04:38:21 GMT

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