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Wiki Macros

Trac macros are plugins to extend the Trac engine with custom 'functions' written in Python. A macro inserts dynamic HTML data in any context supporting WikiFormatting.

Another kind of macros are WikiProcessors. They typically deal with alternate markup formats and representation of larger blocks of information (like source code highlighting).

Using Macros

Macro calls are enclosed in two square brackets. Like python functions, macros can also have arguments, a comma separated list within parentheses.

Examples

 [[Timestamp]]

Display:

Wed Nov 13 02:18:34 2024 

 [[HelloWorld(Testing)]]

Display:

Hello World, args = Testing

Available Macros

Note that the following list will only contain the macro documentation if you've not enabled -OO optimizations, or not set the PythonOptimize option for mod_python.

[[TicketQuery]]

Macro that lists tickets that match certain criteria.

This macro accepts two parameters, the second of which is optional.

The first parameter is the query itself, and uses the same syntax as for query: wiki links. The second parameter determines how the list of tickets is presented: the default presentation is to list the ticket ID next to the summary, with each ticket on a separate line. If the second parameter is given and set to compact then the tickets are presented as a comma-separated list of ticket IDs.

[[TitleIndex]]

Inserts an alphabetic list of all wiki pages into the output.

Accepts a prefix string as parameter: if provided, only pages with names that start with the prefix are included in the resulting list. If this parameter is omitted, all pages are listed.

[[RecentChanges]]

Lists all pages that have recently been modified, grouping them by the day they were last modified.

This macro accepts two parameters. The first is a prefix string: if provided, only pages with names that start with the prefix are included in the resulting list. If this parameter is omitted, all pages are listed.

The second parameter is a number for limiting the number of pages returned. For example, specifying a limit of 5 will result in only the five most recently changed pages to be included in the list.

[[PageOutline]]

Displays a structural outline of the current wiki page, each item in the outline being a link to the corresponding heading.

This macro accepts three optional parameters:

  • The first is a number or range that allows configuring the minimum and maximum level of headings that should be included in the outline. For example, specifying "1" here will result in only the top-level headings being included in the outline. Specifying "2-3" will make the outline include all headings of level 2 and 3, as a nested list. The default is to include all heading levels.
  • The second parameter can be used to specify a custom title (the default is no title).
  • The third parameter selects the style of the outline. This can be either inline or pullout (the latter being the default). The inline style renders the outline as normal part of the content, while pullout causes the outline to be rendered in a box that is by default floated to the right side of the other content.
[[Image]]

Embed an image in wiki-formatted text.

The first argument is the file specification. The file specification may reference attachments or files in three ways:

  • module:id:file, where module can be either wiki or ticket, to refer to the attachment named file of the specified wiki page or ticket.
  • id:file: same as above, but id is either a ticket shorthand or a Wiki page name.
  • file to refer to a local attachment named 'file'. This only works from within that wiki page or a ticket.

Also, the file specification may refer to repository files, using the source:file syntax.

The remaining arguments are optional and allow configuring the attributes and style of the rendered <img> element:

  • digits and unit are interpreted as the size (ex. 120, 25%) for the image
  • right, left, top or bottom are interpreted as the alignment for the image
  • nolink means without link to image source.
  • key=value style are interpreted as HTML attributes or CSS style indications for the image. Valid keys are:
    • align, border, width, height, alt, title, longdesc, class, id and usemap
    • border can only be a number

Examples: 

    [[Image(photo.jpg)]]                           # simplest
    [[Image(photo.jpg, 120px)]]                    # with size
    [[Image(photo.jpg, right)]]                    # aligned by keyword
    [[Image(photo.jpg, nolink)]]                   # without link to source
    [[Image(photo.jpg, align=right)]]              # aligned by attribute

You can use image from other page, other ticket or other module. 

    [[Image(OtherPage:foo.bmp)]]    # if current module is wiki
    [[Image(base/sub:bar.bmp)]]     # from hierarchical wiki page
    [[Image(#3:baz.bmp)]]           # if in a ticket, point to #3
    [[Image(ticket:36:boo.jpg)]]
    [[Image(source:/images/bee.jpg)]] # straight from the repository!
    [[Image(htdocs:foo/bar.png)]]   # image file in project htdocs dir.

Adapted from the Image.py macro created by Shun-ichi Goto <gotoh@taiyo.co.jp>

[[MacroList]]

Displays a list of all installed Wiki macros, including documentation if available.

Optionally, the name of a specific macro can be provided as an argument. In that case, only the documentation for that macro will be rendered.

Note that this macro will not be able to display the documentation of macros if the PythonOptimize option is enabled for mod_python!

[[TracGuideToc]]

This macro shows a quick and dirty way to make a table-of-contents for a set of wiki pages.

[[Timestamp]]

Inserts the current time (in seconds) into the wiki page.

[[HelloWorld]]

Example macro.

Macros from around the world

The Trac Project has a section dedicated to user-contributed macros, MacroBazaar. If you're looking for new macros, or have written new ones to share with the world, don't hesitate adding it to the MacroBazaar wiki page.

Developing Custom Macros

Macros, like Trac itself, are written in the Python programming language. They are very simple modules, identified by the filename and should contain a single entry point function. Trac will display the returned data inserted into the HTML where the macro was called.

It's easiest to learn from an example: 

# MyMacro.py -- The world's simplest macro

def execute(hdf, args, env):
    return "Hello World called with args: %s" % args

You can also use the environment (env) object, for example to access configuration data and the database, for example: 

def execute(hdf, txt, env):
    return env.get_config('trac', 'repository_dir')

Note that since version 0.9, wiki macros can also be written as TracPlugins. This gives them some capabilities than “classic” macros do not have, such as directly access the HTTP request.

For more information about developing macros, see the development resources on the main project site.

See also: WikiProcessors, WikiFormatting, TracGuide