- From: Edward O'Connor <eoconnor@apple.com>
- Date: Tue, 24 Jul 2012 10:37:20 -0700
- To: whatwg@lists.whatwg.org
Hi, The spec currently disallows conformance checkers from reporting <img> elements without alt="" attributes as an error when <meta name=generator> is present[1]. This is problematic for two reasons: 1. Many tools which insert <meta name=generator> have done so for years simply as a means to mark content made with the tool, for marketing or similar reasons. Users of such tools want conformance checkers to catch missing alt="", and authors of such tools have stated that they are unwilling to stop emitting markup tagged with <meta name=generator>. 2. <meta name=generator> is a very coarse mechanism which applies to the entire document. Individual pages on large web sites are typically a mixture of content that comes partly from hand-authored templates and partly pragmatically generated. In such cases, a finer-grained mechanism could help template authors create accessible markup. For instance, consider a photo detail page at Flickr. The main content image is uploaded by Flickr users, who may have done so in bulk and it would be unreasonable for Flickr to prompt their users to provide alt="" text for all of their images. Other content images on the page may be present in Flickr's own templates; the Flickr developers would benefit from conformance checkers which would catch missing alt="" for the content images in the template but which would not warn about missing alt="" for the main, user-sourced image. We could address this problem by making changes along these lines: 1. Drop the <meta name=generator> alt="" exception. 2. Mint a global boolean attribute that, when present, indicates that the element and its descendants are outside of the page author's control (at least insofar as author conformance criteria are concerned). 3. Add a new exception to the "Guidance for conformance checkers" section which prevents conformance checkers from emitting errors for missing alt="" in subtrees marked with the new attribute. Some issues that come to mind: 1. What other author conformance criteria should conformance checkers relax in such subtrees? 2. Authors might start including such an attribute on the <html> element just to get some kind of "valid html5" badge without actually improving their pages. 3. What's a good name for such an attribute? Ted 1. http://www.whatwg.org/specs/web-apps/current-work/multipage/embedded-content-1.html#guidance-for-conformance-checkers
Received on Tuesday, 24 July 2012 17:37:55 UTC