Re: DOCBOOK-APPS: XInclude doesn't validate with xmllint

[Elliotte Rusty Harold <elharo@metalab.unc.edu>]

It would be helpful to remember that it is possible today to write 
DocBook documents that are completely valid before and after 
XInclusions, without any modifications to the core DocBook DTD. You 
just need to add an internal subset to you documents that adds 
xinclude:include to the content models of those elements where you've 
chosen to place an XInclude element. For example, the chapter 
documents for Processing XML with Java 
<http://www.ibiblio.org/xml/books/xmljava/> all begin like this:

<!DOCTYPE chapter PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
                       "docbook/docbookx.dtd" [
  <!-- add XIncludes -->                    
  <!ENTITY % local.para.char.mix " | xinclude:include">
  <!ELEMENT xinclude:include EMPTY>
  <!ATTLIST xinclude:include
     xmlns:xinclude CDATA #FIXED "http://www.w3.org/2001/XInclude";
     href           CDATA #REQUIRED
     parse          (text | xml) "xml"
  >       
]>

Authors who use XIncludes in different places may need to change 
different parameter entities. However, I'm pretty sure the technique 
is broadly applicable.
-- 

+-----------------------+------------------------+-------------------+
| Elliotte Rusty Harold | elharo@metalab.unc.edu | Writer/Programmer |
+-----------------------+------------------------+-------------------+
|          XML in a  Nutshell, 2nd Edition (O'Reilly, 2002)          |
|              http://www.cafeconleche.org/books/xian2/              |
|  http://www.amazon.com/exec/obidos/ISBN%3D0596002920/cafeaulaitA/  |
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