Trac supports language-specific syntax highlighting of source code within wiki formatted text in [wiki processors] blocks and in the [TracBrowser repository browser]. Syntax coloring is provided using http://pygments.org/ Pygments, which covers a wide range of programming languages and other structured texts, and is actively supported. If Pygments is not available, Trac will display the content as plain text.
[Pygments] is a highlighting library implemented in pure python, very fast, easy to extend and http://pygments.org/docs/ well documented.
The Pygments default style can specified in the [TracIni#mimeviewer-section mime-viewer] section of trac.ini. The default style can be overridden by setting a //Style// preference on the [/prefs/pygments preferences page].
[Pygments lexer] options can be specified as [WikiProcessors WikiProcessor] arguments and defaults can be set in the TracIni#pygments-lexer-section environment configuration.
The list of currently supported languages can be found on the [supported languages] page. The list represents the languages supported in the most recent version of Pygments, so the languages actually supported in your installation could differ if you have an older version installed. The listing of http://pygments.org/docs/lexers/ supported lexers provides additional information about the default mime type to keyword mappings.
Explicit control of the mime type associated with a [WikiProcessors WikiProcessor] and file extension is available through the mime_map setting. For example, by default .m files are considered Objective-C files. In order to treat .m files as MATLAB files, add text/matlab:m to the mime_map setting in the [wiki:TracIni#mimeviewer-section "[mimeviewer] section of trac.ini"].
If a mimetype property such as svn:mime-type is set to text/plain, there is no coloring even if file is known type like java.
Rich content may be directly //rendered// instead of syntax highlighted. This usually depends on which auxiliary packages are installed and on which components are activated in your setup. For example a text/x-rst document will be rendered via docutils if it is installed and the trac.mimeview.rst.ReStructuredTextRenderer is not disabled, and will be syntax highlighted otherwise.
In a similar way, a document with the mimetype text/x-trac-wiki is rendered using the Trac wiki formatter, unless the trac.mimeview.api.WikiTextRenderer component is disabled.
HTML documents are directly rendered only if the render_unsafe_html settings are enabled in the TracIni (those settings are present in multiple sections, as there are different security concerns depending where the document comes from). If you want to ensure that an HTML document gets syntax highlighted and not rendered, use the text/xml mimetype.
[[KnownMimeTypes]]
See also: WikiProcessors, WikiFormatting, TracWiki, TracBrowser
