= Wiki Processors =

Processors are WikiMacros designed to provide alternative markup formats for the [TracWiki Wiki engine]. Processors can be thought of as ''macro functions to process user-edited text''. 

The Wiki engine uses processors to allow using [wiki:WikiRestructuredText Restructured Text], [wiki:WikiHtml raw HTML] and [http://www.textism.com/tools/textile/ textile] in any Wiki text throughout Trac.


== Using Processors ==

To use a processor on a block of text, use a Wiki code block, selecting a processor by name using ''shebang notation'' (#!), familiar to most UNIX users from scripts.

'''Example 1''' (''inserting raw HTML in a wiki text''):

{{{
#!html
<pre class="wiki">{{{
#!html
&lt;h1 style="color: orange"&gt;This is raw HTML&lt;/h1&gt;
}}}</pre>
}}}

'''Results in:'''
{{{
#!html
<h1 style="color: orange">This is raw HTML</h1>
}}}

----

'''Example 2''' (''inserting Restructured Text in wiki text''):

{{{
#!html
<pre class="wiki">{{{
#!rst
A header
--------
This is some **text** with a footnote [*]_.

.. [*] This is the footnote.
}}}</pre>
}}}

'''Results in:'''
{{{
#!rst
A header
--------
This is some **text** with a footnote [*]_.

.. [*] This is the footnote.
}}}
----
'''Example 3''' (''inserting a block of C source code in wiki text''):

{{{
#!html
<pre class="wiki">{{{
#!c
int main(int argc, char *argv[])
{
  printf("Hello World\n");
  return 0;
}
}}}</pre>
}}}

'''Results in:'''
{{{
#!c
int main(int argc, char *argv[])
{
  printf("Hello World\n");
  return 0;
}
}}}

----

== Available Processors ==
The following processors are included in the Trac distribution:
 * '''html''' -- Insert custom HTML in a wiki page. See WikiHtml.
 * '''rst''' -- Trac support for Restructured Text. See WikiRestructuredText.
 * '''textile''' -- Supported if  [http://dealmeida.net/projects/textile/ Textile] is installed. See [http://hobix.com/textile/ a Textile reference].

Textile link above is rotten. [http://www.textism.com/tools/textile/ this one] works, allows to test example.

=== Code Highlighting Support ===
Trac includes processors to provide inline [wiki:TracSyntaxColoring syntax highlighting] for the following languages:
 * '''c''' -- C
 * '''cpp''' -- C++
 * '''python''' -- Python
 * '''perl''' -- Perl
 * '''ruby''' -- Ruby
 * '''php''' -- PHP
 * '''asp''' --- ASP
 * '''sql''' -- SQL
 * '''xml''' -- XML
'''Note:''' ''Trac relies on external software packages for syntax coloring. See TracSyntaxColoring for more info.''

By using the MIME type as processor, it is possible to syntax-highlight the same languages that are supported when browsing source code. For example, you can write:
{{{
{{{
#!text/html
<h1>text</h1>
}}}
}}}

The result will be syntax highlighted HTML code. The same is valid for all other mime types supported.


For more processor macros developed and/or contributed by users, visit: 
 * [http://projects.edgewall.com/trac/wiki/ProcessorBazaar ProcessorBazaar]
 * [http://projects.edgewall.com/trac/wiki/MacroBazaar MacroBazaar]


== Advanced Topics: Developing Processor Macros ==
Developing processors is no different from WikiMacros. In fact they work the same way, only the usage syntax differs. See WikiMacros for more information.

'''Example:''' (''Restructured Text Processor''):
{{{
#!python
from docutils.core import publish_string

def execute(hdf, text, env):
    html = publish_string(text, writer_name = 'html')
    return html[html.find('<body>')+6:html.find('</body>')].strip()
}}}

----
See also: WikiMacros, WikiHtml, WikiRestructuredText, TracSyntaxColoring, WikiFormatting, TracGuide