- From: Boris Zbarsky <bzbarsky@MIT.EDU>
- Date: Mon, 01 Jun 2009 13:14:39 -0400
- To: Joe D Williams <joedwil@earthlink.net>, HTML WG <public-html@w3.org>
Joe D Williams wrote: > classid started out in IE and became useful to me when different X3D > players adopted their individual classid values. But classid was limited > to IE and would never work in other html browsers and often (more like > everytime, with aggression) broke any object element that included a > classid. I always wondered why clasid didn't work everywhere. Precisely because it works as you want. IE uses ActiveX plug-ins. The classids you specify refer to those particular plug-ins. Other UAs use NPAPI plug-ins, which you're explicitly saying you don't want when you use the ActiveX classid values (anything starting with "clsid:" and followed by a UUID). Note that non-IE browsers do support some values of classid (e.g. "java:something" values). > Anyway, for this to work meaningfully then processes the plugin uses to > register classid must be as open and easy and predictable as when > registering MIME type and file extension handling. Yes, indeed, but it's not. And worse yet, since classid as currently defined means a particular implementation you'd need different classids for, say, Flash on Mac and Flash on Windows (esp. since they they do in fact differ in behavior). At which point your site above would suddenly break for all Mac users unless you were much more careful than the typical web developer. The edge case of selecting a particular plug-in if the user has several different ones that all handle the same type _and_ is not capable of picking one himself _and_ the web developer knows what the user has installed _and_ the web developer is capable of making that choice well doesn't seem to be worth the many ways the feature can be accidentally misused without realizing it. For example, any use of an <object> with classid without a fallback that renders purely based on MIME type would be such a misuse... -Boris
Received on Monday, 1 June 2009 17:15:26 UTC