Include child elements with xpointer element() scheme

Question

I am trying to include all child elements (sections) of an element from a.xml into b.xml with xi:include. Both XML files are valid docbook 5 files.

a.xml

<chapter xml:id="TheChapter">
    <section>
        <title>section 1</title>
    </section>
    <section>
        <title>section 2</title>
    </section>
    <section>
        <title>section 3</title>
    </section>
</chapter>

b.xml

<section>
      <xi:include href="a.xml" xpointer="element(/TheChapter/*)"/>
</section>

I am using XMLMind which reports an error.

cannot parse inclusion directive: cannot parse XPointer "element(/TheChapter/*)": "/TheChapter/*", XPointer element() scheme syntax error

Is my use of element() scheme not correct?

Answer 1

Your use of the element() scheme is not correct.

• The first portion of the expression identifying an element via its ID should not start with a forward slash.
• Wildcards (*) cannot be used. The "child sequence" can contain forward slashes and numbers only.

This is a valid expression:

element(TheChapter/1)

It will select the first child of the element identified by the TheChapter ID. What you want cannot be done using the element() scheme.

---

You could use the xpointer() scheme:

xpointer(id('TheChapter')/*)

The xpointer() scheme never became a W3C recommendation (it's still just a draft) and it is not widely implemented.

XMLmind XML Editor does support a subset of xpointer(). Here is a mailing list post with some more details: http://permalink.gmane.org/gmane.editors.xxe.general/10220.

Answer 2

The following usage works fine:

<xi:include href="a.xml" xpointer="xmlns(db=http://docbook.org/ns/docbook) xpointer(id('TheChapter')/db:section)"/>

Or

<xi:include href="a.xml" xpointer="xmlns(db=http://docbook.org/ns/docbook) xpointer(id('TheChapter')/*)"/>