= 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
<h1 style="color: orange">This is raw HTML</h1>
}}}
}}}

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

Note that since 0.11, such blocks of HTML have to be self-contained, i.e. you can't start an HTML element in one block and close it later in a second block. Use div or span processors for achieving similar effect (see WikiHtml).

----

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

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

.. [*] This is the footnote.
}}}
}}}

'''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''):

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

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

----
'''Example 4''' (''Searching from a wiki page by custom field. Allows user to reuse most common searches on a wiki page''):

{{{
{{{
#!html
<form action="/query" method="get">
<input type="text" name="keywords" value="~" size="30"> <input type="submit" value="Search by Keywords#">
<!-- To control what fields show up use hidden fields
<input type="hidden" name="col" value="id">
<input type="hidden" name="col" value="summary">
<input type="hidden" name="col" value="status">
<input type="hidden" name="col" value="milestone">
<input type="hidden" name="col" value="version">
<input type="hidden" name="col" value="owner">
<input type="hidden" name="col" value="priority">
<input type="hidden" name="col" value="component">
-->
</form>
}}}
}}}


''' Result:'''
{{{
#!html
<form action="/query" method="get">
<input type="text" name="keywords" value="~" size="30"> <input type="submit" value="Search by Keywords#">
<!-- To control what fields show up use hidden fields
<input type="hidden" name="col" value="id">
<input type="hidden" name="col" value="summary">
<input type="hidden" name="col" value="status">
<input type="hidden" name="col" value="milestone">
<input type="hidden" name="col" value="version">
<input type="hidden" name="col" value="owner">
<input type="hidden" name="col" value="priority">
<input type="hidden" name="col" value="component">
-->
</form>
}}}


----

== Available Processors ==
The following processors are included in the Trac distribution:
 * '''html''' -- Insert custom HTML in a wiki page. See WikiHtml.
 * '''div''' -- Wrap an arbitrary Wiki content in a <div> element (''since 0.11''). See WikiHtml.
 * '''span''' -- Wrap an arbitrary Wiki content in a <span> element (''since 0.11''). See also WikiHtml.
 * '''rst''' -- Trac support for Restructured Text. See WikiRestructuredText.
 * '''textile''' -- Supported if [http://cheeseshop.python.org/pypi/textile Textile] is installed. See [http://www.textism.com/tools/textile/ a Textile reference].
 * '''comment''' -- Do not process the text in this section (i.e. contents exist only in the plain text that can be viewed when editing the wiki page content - not in the rendered page).
 * '''diff''' -- Pretty print patches and diffs.

=== Code Highlighting Support ===
Trac includes processors to provide inline [wiki:TracSyntaxColoring syntax highlighting] for the following languages:
 * '''c''' -- C
 * '''cpp''' -- C++
 * '''csharp''' --- C#
 * '''python''' -- Python
 * '''perl''' -- Perl
 * '''ruby''' -- Ruby
 * '''php''' -- PHP
 * '''asp''' -- ASP
 * '''java''' -- Java
 * '''js''' -- Javascript
 * '''sql''' -- SQL
 * '''xml''' -- XML
 * '''sh''' -- Bourne/Bash shell

'''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:
{{{
#!text/html
<h1>text</h1>
}}}

The same is valid for all other [TracSyntaxColoring#SyntaxColoringSupport mime types supported].

For more processor macros developed and/or contributed by users, visit the [th:WikiStart Trac Hacks] community site.

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


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