49462 - XML Base should affect processing instruction href

Status: RESOLVED INVALID

(Core :: XML, defect, P3)

Description

[Heikki Toivonen (remove -bugzilla when emailing directly)]

From the spec:

"A relative URI appearing in the content of a processing instruction is resolved 
against the base URI described by the xml:base attribute of the nearest ancestor 
element having an xml:base attribute."

Currently we only care about XML Base in the context of simple XLinks.

Comment 1

[Chris Petersen]

Heikki,

Thanks for the link to XML base document.Read the spec and made a few QA tests . 
At first glance, it looked like you would need to specfiy a namespace for base 
but that appears not to be the case.Since you need to declare xlink namespace, 
this must cover this attribute. Yes ?

Comment 2

[Heikki Toivonen (remove -bugzilla when emailing directly)]

XML Base is totally independent of XLink. XLink depends on XML Base.

Now, XML Base is declared with adding the attribute "xml:base" to XML elements. 
There is no need to declare namespace for the prefix "xml"; it is implicitly set  
so you can just use it. The namespace prefix "xml" is also reserved so I guess 
it would be illegal to try and define it.

XML Base is scoped, so if you need to get the XML Base for some element you need 
to traverse the parents of that element to compute the full absolute XML Base 
URI. There are samples/tests of the use of XML Base in the context of simple 
XLinks in mozilla/layout/xml/tests/xmlbase/xmlbase.xml

I'll give an example how this affects PIs (processing instructions):

<?xml version="1.0"?>
<?xml-stylesheet href="http://www.mozilla.org/style.css" type="text/css">
<doc xml:base="http://www.netscape.com">
  <?xml-stylesheet href="/style.css" type="text/css">
<doc>

The first stylesheet PI gets the style.css from the www.mozilla.org server. The 
second PI is inside the effect of XML Base that has been set on the doc element, 
so the second PI will get its style.css from the www.netscape.com server.

Comment 3

[Heikki Toivonen (remove -bugzilla when emailing directly)]

XML Base is still a working draft, and lately there has been some discussion 
about whether XML Base should affect PIs or not. Based on these uncertainties 
and the workaround of using absolute URIs I am going to Future this.

This bug has been marked "future" because the original netscape engineer working 
on this is over-burdened. If you feel this is an error, that you or another
known resource will be working on this bug,or if it blocks your work in some way 
-- please attach your concern to the bug for reconsideration.

Comment 4

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Not that important yet I think...

Comment 5

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Hmm... xml-stylesheet can only appear in document prolog, the example with
stylesheets was wrong.

With the current implementation of DOM 3 baseURI (not yet checked in) you would
get to proper baseURI for PI as well.

Comment 6

[Boris Zbarsky [:bzbarsky]]

XML processing instructions implement BaseURI correctly.  Since the PIs
themselves never do anything, it's the caller that needs to make sure to get the
base URI off the PI when resolving relative URIs.

So is there anything left to do here?

Comment 7

[Heikki Toivonen (remove -bugzilla when emailing directly)]

I think we can close this.