- From: <bugzilla@jessica.w3.org>
- Date: Thu, 09 Jun 2011 12:08:04 +0000
- To: public-html@w3.org
http://www.w3.org/Bugs/Public/show_bug.cgi?id=12924 Summary: xml:base interaction with img element Product: HTML WG Version: unspecified Platform: Macintosh OS/Version: All Status: NEW Severity: normal Priority: P2 Component: HTML5 spec (editor: Ian Hickson) AssignedTo: ian@hixie.ch ReportedBy: alex@milowski.org QAContact: public-html-bugzilla@w3.org CC: mike@w3.org, public-html-wg-issue-tracking@w3.org, public-html@w3.org In reading the section about the 'img' element [1], I see the statement: "A user agent that obtains images immediately must synchronously update the image data of an img element whenever that element is either created with a src attribute, or has its src attribute set, changed, or removed." In documents (e.g. XHTML5) where xml:base is allowed, the 'src' attribute will be resolved against the element's base URI derived from the xml:base attribute. The result is that if an xml:base attribute is present in the original markup, it will affect the resolved URI derived from the 'src' attribute. If that xml:base attribute is later programmatically changed, it is unclear what the user agent should do. The 'src' attribute has not been changed and so it will not be resolved again. Unfortunately, the base URI has changed and the resolved URI is no longer necessarily valid. This gets even more complicated if the xml:base attribute is on an ancestor of the 'img' element and causes the base URI to change for a whole subtree. I believe the specification should be clear one way or the other what the user agent should do with resolved URI values if the base URI is changed programmatically via an xml:base attribute change. It may be the case that a change to the base URI after resolving URI values should be viewed as "bad practice." As such, we shouldn't incur the penalty of resolving all URI values on all such elements in the affected subtree. That is, unless someone can show a valid use case or contradiction that could subsequently be derived (e.g. consistency). It should be noted that xml:base's influence on the resolved location works quite well in browsers that currently support it for content that is added the DOM programmatically as long as the xml:base attribute exists on an element before it is added to the DOM. [1] http://www.w3.org/TR/html5/embedded-content-1.html#the-img-element -- Configure bugmail: http://www.w3.org/Bugs/Public/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.
Received on Thursday, 9 June 2011 12:08:06 UTC