- From: Maciej Stachowiak <mjs@apple.com>
- Date: Tue, 15 Jun 2010 21:37:46 -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
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 UTC