Wiki Processors

Processors are WikiMacros designed to provide alternative markup formats for the Trac 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 and raw HTML in any wiki text throughout Trac.

Using Processors

To use a processor on a block of text, use a wiki blockquote, 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

This is raw HTML

}}}

Results in:

This is raw HTML

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.
  • rst -- Trac support for Restructured Text. See WikiRestructuredText.
  • textile -- Supported if Textile is installed.

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
  • 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

text

}}}

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:

  • ProcessorBazaar
  • MacroBazaar

Advanced Topics: Developing Processor Macros

Developing processors is no different than WikiMacros. In fact they work the same way, only the usage syntax differs. See WikiMacros for more information.

Example: (Restructured Text Processor): 

from docutils.core import publish_string
def execute(hdf, text, env):
    html = publish_string(text, writer_name = 'html')
    return html[html.find('')+6:html.find('')].strip()

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