- From: Ian Hickson <ian@hixie.ch>
- Date: Wed, 13 Feb 2008 01:15:07 +0000 (UTC)
On Mon, 13 Aug 2007, Jonas Sicking wrote: > Ian Hickson wrote: > > > Also, if we're going to be inconsistent in how current browsers and web > > > pages handle multiple <base>s, why not simply use the first <base> for > > > both href="" and target=""? > > > > Done. > > I realized another limitation. It is very hard for implementations to > 'correctly' deal with dynamic modifications to bases. Ideally all > external resources, such as <iframe>s, <img>s, css backgrounds, > <svg:use> elements and css @imports should be updated to potentially use > new URIs. This can happen when <base> elements and xml:base attributes > are inserted or mutated. So far no UA that I know of does this, and it > would be very hard to implement. I completely agree with you that this is an area that is problematic. > What I suggest is that we add similar language as the XBL spec does for > xmlns attributes and xbl:attr attributes. Say that dynamic modifications > are allowed, but that the implementation is not expected to update the > resolved URI unless the URI is explicitly touched. Unfortunately it's unclear when that would be. At least with xbl:attr we have a somewhat well-defined set of steps for when things happen. Here it's far less clear. For example, clicking a link is likely to reresolve the URI relative to the base URI. Maybe even hovering it might. Or maybe even just a repaint in general. I'm not sure what to do here. It seems like UAs should support a notification mechanism so that when a base URI is changed, all URIs in the document (for <base>) or in that subtree (for xml:base) get reresolved. That actually seems relatively simple and has little (no) overhead in the common case of nothing being changed. -- Ian Hickson U+1047E )\._.,--....,'``. fL http://ln.hixie.ch/ U+263A /, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
Received on Tuesday, 12 February 2008 17:15:07 UTC