On 18/11/13 16:36, matmarquis.com wrote:
I recall that some of the more specific resistance was due to the complication involved in implementing and testing existing media elements, but I can’t claim to understand precisely what manner of browser-internal complications `source` elements brought to the table.
The fundamental issue is atomicity; setting one or N attributes is an atomic operation from the point of view of script; creating N elements is not. This creates complexity because the algorithm has to deal with the possibility of DOM mutation changing the set of available sources before it has selected the correct one. I believe there was a proposal that simplified the semantics by ignoring mutations, but I hear it ran into problems with animated images, which I haven't understood in detail.
