- From: Simon Pieters <simonp@opera.com>
- Date: Thu, 12 Sep 2013 12:19:24 +0200
- To: HTMLwg <public-html@w3.org>
The design using multiple elements makes the implementation much more complex compared to a design using a single element. I've mentioned this before [1]. <source> for <video> and <audio> is also too complex. My experience with quality assurance for <video> at Opera suggests that <source> is a mistake that we should not repeat. There are too many edge cases. If I had realized this before it shipped in browsers I would have argued that <video> be changed to not use <source> elements, but now we're stuck with it. The argument against this I usually get is that the Priority of Constituencies design principle says that the needs of authors should win over the needs of implementors. However, this design principle needs to be considered together with the rest of the design principles, in particular in this case Avoid Needless Complexity [2]. In the case of resource selection using one element vs. using multiple elements, I would argue that the latter is about an order of magnitude more complex in the implementation and the needed tests because it enables more edge cases that simply cannot happen when you only have one element. To illustrate my point, I have submitted some of the tests I've written for media elements' resource selection algorithm which test for a few of these edge cases. http://w3c-test.org/web-platform-tests/submissions/326/html/semantics/embedded-content-0/media-elements/loading-the-media-resource/ (If you have comments on the tests, please use https://critic.hoppipolla.co.uk/r/307 , thanks!) So for instance a test like http://w3c-test.org/web-platform-tests/submissions/326/html/semantics/embedded-content-0/media-elements/loading-the-media-resource/031.html wouldn't be a possible case to test if it was a single element. With this in mind, my recommendation is to make it a requirement for the solution to responsive images to use a single element, <img>. You can use a single attribute or multiple attributes to address the various use cases, that doesn't make a significant difference to the complexity. [1] http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2012-May/035784.html [2] http://www.w3.org/TR/html-design-principles/#avoid-needless-complexity -- Simon Pieters Opera Software
Received on Thursday, 12 September 2013 10:19:54 UTC