- From: Jonas Sicking <jonas@sicking.cc>
- Date: Tue, 15 Jun 2010 22:46:05 -0700
- To: Maciej Stachowiak <mjs@apple.com>
- Cc: Ian Hickson <ian@hixie.ch>, Sam Ruby <rubys@intertwingly.net>, Steven Faulkner <faulkner.steve@gmail.com>, public-html@w3.org
One thing that would be good to get clarified is how a UA is supposed to handle <a role=button>. So far it seems like most of the discussions revolve around what is valid or not, this question mostly affects validators, but not UAs. I.e. this is mostly a question of if we recommend such markup or not. This is arguably a minor issue. The much more, IMHO, important question is what the UA requirements are with regards to <a role=button>. Do we require that UAs ignore the role attribute and tell for example AT tools that it is a link? Or do we forward the role attribute to AT APIs? I think a good argument could be made that if someone has gone through the trouble to add 'role=button' to an element, then that is likely the most accurate role. Thus I think a reasonable argument could be made that we should forward this information to AT users. / Jonas On Tue, Jun 15, 2010 at 9:37 PM, Maciej Stachowiak <mjs@apple.com> wrote: > > 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 05:54:38 UTC