Xerces supports XInclude with the "element" XPointer, which refers to
an ID.  However, while this works fine with ID attributes that are
defined in a DTD, it does not work if the IDs are declared using xml:id.
This makes the "element" syntax useless for including documents that do
not contain a DOCTYPE declaration, which includes many useful XML
formats (e.g. XHTML5).

It would be nice if Xerces would support this.

Hi Brian,

Can you confirm that your issue is the same one reported upstream here:

https://issues.apache.org/jira/browse/XERCESJ-1113

It looks similar; unfortunately upstream has passed on this for 4 years now...

Thank you,
Tony

tags 605389 + patch
kthxbye

Attached is a patch to implement the required behavior to support
xml:id.

Hey.  If you want the submitter to see your reply, you need to use
-submitter or CC him/her directly; the BTS does not do it by default.

Yes.

My implementation does not verify the constraints required by the xml:id
specification, and it does not do additional normalization for types of
ID.  I'm happy to modify it so that it does.  I believe that should be
sufficient to handle xml:id in a conforming way with XInclude.

I can look into creating a specific feature for enabling xml:id
processing, if that's what upstream wants, as long as (1) they'll accept
a reasonable implementation, (2) they specify what URI they want to
use to refer to xml:id processing (e.g., for SAX), and (3) it is enabled
by default.  You can feel free to forward this to them; I have an Apache
bugzilla account, but not a JIRA account, and I'm not particularly
interested in creating one.  (Having two separate BTSes is silly, IMO.)

According to the upstream bug[0], it looks like Xerces will likely gain
some decent xml:id support soon.  If it is not enabled by default, there
will need to be some way to tell ant to turn it on when parsing XML for
Xalan.

[0] https://issues.apache.org/jira/browse/XERCESJ-1113