XInclude processing

If you are using Xerces as your XML parser, you can have Xerces expand any XInclude directives.

The -xi option on the command line causes XInclude processing to be applied to all input XML documents. This includes source documents, stylesheets, and schema documents listed on the command line, and also those loaded indirectly for example by calls on the doc() function or by mechanisms such as xsl:include and xs:include.

From the Java API, the equivalent is to call setXInclude() on the Configuration object, or to set the configuration property XINCLUDE to true.

XInclude processing can be requested at a per-document level by creating an AugmentedSource and calling its setXIncludeAware() method. The corresponding method is also recognized on Saxon's implementation of the JAXP DocumentBuilderFactory. When the doc() or document() or collection() function is called from an XPath expression, XInclude processing can be enabled by including xinclude=yes among the query parameters in the URI.

It is possible to request XInclude processing for the documents in a collection by including the query parameter xinclude=yes in the collection URI. Similarly, for a document read using the doc() or document() functions, XInclude processing can be requested using xinclude=yes in the document URI -- but only if the StandardURIResolver is used, and the feature is enabled by calling Configuration.setParameterizedURIResolver() or by setting -p:on on the Query or Transform command lines.

The xsl:source-document instruction can enable XInclude processing using the extension attribute saxon:xinclude="yes".

It is also possible to switch on XInclude processing (for all documents) by setting the system property:

-Dorg.apache.xerces.xni.parser.XMLParserConfiguration= org.apache.xerces.parsers.XIncludeParserConfiguration

An alternative approach is to incorporate an XInclude processor as a SAX filter in the input pipeline. You can find a suitable SAX filter at http://xincluder.sourceforge.net/, and you can incorporate it into your application as described in Writing Input Filters.

On the .NET platform, there is a customized XmlReader that performs XInclude processing available at GitHub project Mvp.Xml.NetStandard. You can supply this as an argument to the method Build(XmlReader parser) in the DocumentBuilder class of the .NET Saxon API. (Not tested).

For further information on using XInclude, see http://www.sagehill.net/docbookxsl/Xinclude.html.