- From: Maciej Stachowiak <mjs@apple.com>
- Date: Tue, 15 Jun 2010 19:30:46 -0700
- To: Ian Hickson <ian@hixie.ch>
- Cc: Sam Ruby <rubys@intertwingly.net>, Steven Faulkner <faulkner.steve@gmail.com>, public-html@w3.org
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 02:31:51 UTC