<?xml version="1.0"?>

<!DOCTYPE module SYSTEM "../../../../dtd/module.dtd">

<module name="Module ngx_http_xslt_module"
        link="/en/docs/http/ngx_http_xslt_module.html"
        lang="en">

<section id="summary">

<para>
The <literal>ngx_http_xslt_module</literal> (0.7.8+) is a filter
that transforms XML responses using one or more XSLT stylesheets.
</para>

<para>
This module is not built by default, it should be enabled with the
<literal>--with-http_xslt_module</literal>
configuration parameter.
<note>
This module requires the
<link url="http://www.xmlsoft.org">libxml2 and libxslt</link> libraries.
</note>
</para>

</section>


<section id="example" name="Example Configuration">

<para>
<example>
location / {
    xml_entities    /site/dtd/entities.dtd;
    xslt_stylesheet /site/xslt/one.xslt param=value;
    xslt_stylesheet /site/xslt/two.xslt;
}
</example>
</para>

</section>


<section id="directives" name="Directives">

<directive name="xml_entities">
<syntax><value>path</value></syntax>
<default/>
<context>http</context>
<context>server</context>
<context>location</context>

<para>
Specifies the DTD file that declares character entities.
This file is compiled during the configuration stage.
For technical reasons the module is unable to use the
external subset declared in the processed XML, so it is
ignored and instead a specially defined file is used.
This file should not describe the XML structure, it is
enough to only declare the required character entities, for example:
<example>
&lt;!ENTITY nbsp "&amp;#xa0;"&gt;
</example>
</para>

</directive>


<directive name="xslt_param">
<syntax><value>parameter</value> <value>value</value></syntax>
<default/>
<context>http</context>
<context>server</context>
<context>location</context>
<appeared-in>1.1.18</appeared-in>

<para>
Defines parameters for XSLT stylesheets.
The <value>value</value> is treated as an XPath expression.
The <value>value</value> can contain variables.
To pass a string value to a stylesheet,
the <link id="xslt_string_param"/> directive can be used.
</para>

<para>
There could be several <literal>xslt_param</literal> directives.
These directives are inherited from the previous level if and
only if there are no
<literal>xslt_param</literal> and <link id="xslt_string_param"/>
directives defined on the current level.
</para>

</directive>


<directive name="xslt_string_param">
<syntax><value>parameter</value> <value>value</value></syntax>
<default/>
<context>http</context>
<context>server</context>
<context>location</context>
<appeared-in>1.1.18</appeared-in>

<para>
Defines string parameters for XSLT stylesheets.
XPath expressions in the <value>value</value> are not interpreted.
The <value>value</value> can contain variables.
</para>

<para>
There could be several <literal>xslt_string_param</literal> directives.
These directives are inherited from the previous level if and
only if there are no
<link id="xslt_param"/> and <literal>xslt_string_param</literal>
directives defined on the current level.
</para>

</directive>


<directive name="xslt_stylesheet">
<syntax>
    <value>stylesheet</value>
    [<value>parameter</value>=<value>value</value> ...]</syntax>
<default/>
<context>location</context>

<para>
Defines the XSLT stylesheet and its optional parameters.
A stylesheet is compiled during the configuration stage.
</para>

<para>
Parameters can either be specified separately, or grouped in a
single line using the “<literal>:</literal>” delimiter.
If a parameter includes the “<literal>:</literal>” character,
it should be escaped as “<literal>%3A</literal>”.
Also, <command>libxslt</command> requires to enclose parameters
that contain non-alphanumeric characters into single or double quotes,
for example:
<example>
param1='http%3A//www.example.com':param2=value2
</example>
</para>

<para>
The description of parameters can contain variables, for example,
the whole line of parameters can be taken from a single variable:
<example>
location / {
    xslt_stylesheet /site/xslt/one.xslt
                    $arg_xslt_params
                    param1='$value1':param2=value2
                    param3=value3;
}
</example>
</para>

<para>
It is possible to specify several stylesheets; in this case they
will be applied sequentially in the specified order.
</para>

</directive>


<directive name="xslt_types">
<syntax><value>mime-type</value> ...</syntax>
<default>text/xml</default>
<context>http</context>
<context>server</context>
<context>location</context>

<para>
Enables transformations in responses with the specified MIME types
in addition to “<literal>text/xml</literal>”.
The special value “<literal>*</literal>” matches any MIME type (0.8.29).
If the result of transformation is an HTML response, its MIME type
is changes to “<literal>text/html</literal>”.
</para>

</directive>

</section>

</module>