mod_transform Documentation

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mod_transform uses the "configure/make/make install" mechanism common to many Open Source programs. Most of the dirty work is handled by either configure or Apache's apxs utility. If you have built Apache modules before, there shouldn't be any surprises for you.

The interesting options you can pass to configure are:

  • --with-apxs=/path/to/apache/dir/bin/apxs

    This option is used to specify the location of the apxs utility that was installed as part of apache. Specify the location of the binary, not the directory it is located in.

  • --with-xslt-prefix=PREFIX

    Prefix where libxslt is installed.

  • --with-xslt-exec-prefix=PREFIX

    Exec prefix where libxslt is installed.

  • --with-xml-prefix=PREFIX

    Prefix where libxml2 is installed.

  • --with-xml-exec-prefix=PREFIX

    Exec prefix where libxml2 is installed.

  • --help

    Provides a list of available configure options.

./configure --with-apxs=/usr/sbin/apxs2
make install

Integration into Apache

To activate mod_transform Just add

LoadModule transform_module modules/

to your httpd.conf and restart Apache.

mod_transform also provides two exported functions for other modules to use the XSLT processor:

void mod_transform_set_XSLT(request_rec* r, const char* name) ;
void mod_transform_XSLTDoc(request_rec* r, xmlDocPtr doc) ;

Configuring with Apache

Besides registering an output filter with the name XSLT, mod_transform has the following additional directives:

For details on assigning output filters in Apache 2, please see the Filters Documentation. To get basic XSLT parsing for your xml files, just add the following to your httpd.conf:

AddOutputFilter XSLT xml


Description: Whether to announce this module in the server header.
Syntax: TransformAnnounce [On|Off]
Default: On
Context: server config, virtual host.

Enables or Disables showing mod_transform in the Apache Server Name string.


Description: Cache an XSLT Stylesheet on Server Startup.
Syntax: TransformCache URL FILE_PATH
Default: none
Context: server config, virtual host.

This directive forces a specific XSLT Stylesheet to be preloaded by the server on startup. This can signifigantly increase performance.

TransformCache /project/myfile.xsl /usr/local/share/project/myfile.xsl


Description: Configure optional features
Syntax: TransformOptoins [+|-]option [[+|-]option] ...
Default: XIncludes
Context: server config, virtual host, directory, .htaccess.

This directive can enable or disable specific mod_transform features on a per-location basis.

Enables an overlay of the Apache Document Root as the Root Filesystem for all libXML2 Input/Output operations. For an example with +ApacheFS in effect, consider the following XInclude:
<xi:include href="/xi/special.xml" xmlns:xi="" />
Normally, this would request the file /xi/special.xml directly from the filesystem. With +ApacheFS it will do a Subrequest for this file. This means if your DocumentRoot is /src/vhost1/html, libXML2 will read /src/vhost1/html/xi/special.xml. This provides compatibility with Apache Axkit.
Turns off all previous TransformOptions.
Enables or disables XML Inclusions (XInclude) Version 1.0 support in libXML2.
Example Usage:
<Directory "/path/to/my/docroot">
    TransformOptions +ApacheFS +XIncludes


Description: Force a specific XSLT File to be used.
Syntax: TransformSet FILE_PATH
Default: none
Context: server config, virtual host, directory, .htaccess.

This directive forces a specific XSLT Stylesheet for any files it is applied against.

<LocationMatch /*/index.xml>
    TransformSet  /project/myfile.xsl