# E.20 XincludeFilter The `XincludeFilter` processes a stream for Xinclude tags, and processes the inclusions. This is useful for processing modular XML files. DocBook book files are one example of modular XML files. Usage example: ``` <!-- Render a DocBook book file called manual.xml, which contains Xinclude tags to include individual book sections. --> <copy todir="${manual.dest.dir}"> <filterchain> <xincludefilter basedir="${manual.src.dir}" /> <xsltfilter style="${manual.src.dir}/html.xsl"> <param name="base.dir" expression="${manual.dest.dir}/" /> </xsltfilter> </filterchain> <fileset dir="${manual.src.dir}"> <include name="manual.xml" /> </fileset> </copy> ``` Table E.16:聽Attributes for the `<xincludefilter>` tag NameTypeDescriptionDefaultRequired`basedir``String`The working directory from which to process the `Xincludes`. Relative pathnames in the include tags are based on this location. Project basedirNo`resolveexternals``Boolean`Whether to resolve entities. (see [this link](http://www.php.net/manual/en/class.domdocument.php#domdocument.props.resolveexternals) for details)`false`No