On 7 February 2012 13:42, Mathew Marquis <m...@matmarquis.com> wrote: > > On Tuesday, Feb 7, 2012, at 7:35 AM, David Goss wrote: >> >> On 7 February 2012 11:31:15 +0100, Anselm Hannemann wrote: >>> >>> This is a good solution except the fallback img element would be twice >>> loaded in your case which is not good. >>> There should be the img element containing the standard (normal) size and >>> src elements to add diff. other resolutions. With that the browser won't >>> load the resource twice. >> >> Would it? I think Matthew's example implies that a supporting browser >> *wouldn't* load the src from the <img> unless none of the <source>s got a >> media match. Right? >> > > I’m not sure how it’s intended to work with <video> currently, but I believe > the fallback is only loaded if <video> is unsupported—if none of the sources > match, I believe nothing is displayed. I may be wrong, but that seems to be > the most predictable behavior.
Ah, good point. <video> has its own src attrribute, which is where the default source goes. Then it can be overridden by the last <source> element with a media match, if any. >> >> I'm not really sure whether <source> should get an alt attribute - my >> thinking is that if one alt attribute doesn't correctly describe all the >> <source>s then perhaps they are different content. Matthew's example does >> make sense, in that the extra alt attributes describe the way the image has >> been cropped (although it's still the same image). But maybe it would be >> better to only allow alt on the <img> to reinforce the idea that all the >> <source>s should basically be the same image albeit >> cropped/monochrome/whatever. >> > > I’m with you, here. I’m hesitant to have any logic hinge on the fallback > img, though, as it wouldn’t be strictly required—the fallback content could > be, say, descriptive text instead (Granted I wouldn’t do it, but just trying > to keep things as flexible as possible). I do think all sources should be > described by a single alt tag, though, possibly on <picture> itself? > I guess I've moved away from similarities with <video>, in that I've been thinking of the <img> as the default content, not the fallback content. Going with your angle for a simple example with two sizes: <picture alt="alternative text" src="default.jpg"> <source href="large.jpg" media="min-width:700px" /> <img alt="alternative text" src="default.jpg" /> </picture> The duplication of the alt and default src attributes bothers me, but on reflection perhaps it's better to have consistency with <video>.
