Wiki Processors

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

The Wiki engine uses processors to allow using Restructured Text, raw HTML and  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:

This is raw HTML

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: 

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: 

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.
  • 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  Textile is installed. See  a Textile reference.
  • comment -- Do not process the text in this section (i.e. contents exist only in the plain text - not in the rendered page).

Code Highlighting Support

Trac includes processors to provide inline syntax highlighting for the following languages:

  • c -- C
  • cpp -- 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: 

<h1>text</h1>

The same is valid for all other mime types supported.

For more processor macros developed and/or contributed by users, visit:

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.

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