Trac 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.

Trac macros can also be written as TracPlugins. This gives them some capabilities that macros do not have, such as being able to directly access the HTTP request.

Example

A list of 3 most recently changed wiki pages starting with 'Trac':

 [[RecentChanges(Trac,3)]]

Display:

11/06/11

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.

[[InterTrac]]

Provide a list of known InterTrac prefixes.

[[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.

Alternate format and depth can be specified:

  • format=group: The list of page will be structured in groups according to common prefix. This format also supports a min=n argument, where n is the minimal number of pages for a group.
  • depth=n: limit the depth of the pages to list. If set to 0, only toplevel pages will be shown, if set to 1, only immediate children pages will be shown, etc. If not set, or set to -1, all pages in the hierarchy will be shown.
[[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 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 (source:file@rev works also).

Files can also be accessed with a direct URLs; /file for a project-relative, //file for a server-relative, or http://server/file for absolute location of the file.

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
  • link=some TracLinks... replaces the link to the image source by the one specified using a TracLinks. If no value is specified, the link is simply removed.
  • nolink means without link to image source (deprecated, use link=)
  • 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 image width 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@…>

[[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!

[[TracIni]]

Produce documentation for Trac configuration file.

Typically, this will be used in the TracIni page. Optional arguments are a configuration section filter, and a configuration option name filter: only the configuration options whose section and name start with the filters are output.

[[TracGuideToc]]

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

[[TicketQuery]]

Macro that lists tickets that match certain criteria.

This macro accepts a comma-separated list of keyed parameters, in the form "key=value".

If the key is the name of a field, the value must use the syntax of a filter specifier as defined in TracQuery#QueryLanguage. Note that this is not the same as the simplified URL syntax used for query: links starting with a ? character.

In addition to filters, several other named parameters can be used to control how the results are presented. All of them are optional.

The format parameter determines how the list of tickets is presented:

  • list -- the default presentation is to list the ticket ID next to the summary, with each ticket on a separate line.
  • compact -- the tickets are presented as a comma-separated list of ticket IDs.
  • count -- only the count of matching tickets is displayed
  • table -- a view similar to the custom query view (but without the controls)

The max parameter can be used to limit the number of tickets shown (defaults to 0, i.e. no maximum).

The order parameter sets the field used for ordering tickets (defaults to id).

The desc parameter indicates whether the order of the tickets should be reversed (defaults to false).

The group parameter sets the field used for grouping tickets (defaults to not being set).

The groupdesc parameter indicates whether the natural display order of the groups should be reversed (defaults to false).

The verbose parameter can be set to a true value in order to get the description for the listed tickets. For table format only. deprecated in favor of the rows parameter

The rows parameter can be used to specify which field(s) should be viewed as a row, e.g. rows=description|summary

For compatibility with Trac 0.10, if there's a second positional parameter given to the macro, it will be used to specify the format. Also, using "&" as a field separator still works but is deprecated.

[[TracAdminHelp]]

Displays help for trac-admin commands.

Examples:

[[TracAdminHelp]]               # all commands
[[TracAdminHelp(wiki)]]         # all wiki commands
[[TracAdminHelp(wiki export)]]  # the "wiki export" command
[[TracAdminHelp(upgrade)]]      # the upgrade command
[[InterWiki]]

Provide a description list for the known InterWiki prefixes.

Macros from around the world

The Trac Hacks site provides a wide collection of macros and other Trac plugins contributed by the Trac community. If you're looking for new macros, or have written one that you'd like to share with the world, please don't hesitate to visit that site.

Developing Custom Macros

Macros, like Trac itself, are written in the Python programming language.

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

Implementation

Here are 2 simple examples on how to create a Macro with Trac 0.11? have a look at source:trunk/sample-plugins/Timestamp.py for an example that shows the difference between old style and new style macros and also source:trunk/wiki-macros/README which provides a little more insight about the transition.

Macro without arguments

It should be saved as TimeStamp.py as Trac will use the module name as the Macro name

from datetime import datetime
# Note: since Trac 0.11, datetime objects are used internally

from genshi.builder import tag

from trac.util.datefmt import format_datetime, utc
from trac.wiki.macros import WikiMacroBase

class TimestampMacro(WikiMacroBase):
    """Inserts the current time (in seconds) into the wiki page."""

    revision = "$Rev$"
    url = "$URL$"

    def expand_macro(self, formatter, name, args):
        t = datetime.now(utc)
        return tag.b(format_datetime(t, '%c'))

Macro with arguments

It should be saved as HelloWorld.py (in the plugins/ directory) as Trac will use the module name as the Macro name

from trac.wiki.macros import WikiMacroBase

class HelloWorldMacro(WikiMacroBase):
    """Simple HelloWorld macro.

    Note that the name of the class is meaningful:
     - it must end with "Macro"
     - what comes before "Macro" ends up being the macro name

    The documentation of the class (i.e. what you're reading)
    will become the documentation of the macro, as shown by
    the !MacroList macro (usually used in the WikiMacros page).
    """

    revision = "$Rev$"
    url = "$URL$"

    def expand_macro(self, formatter, name, args):
        """Return some output that will be displayed in the Wiki content.

        `name` is the actual name of the macro (no surprise, here it'll be
        `'HelloWorld'`),
        `args` is the text enclosed in parenthesis at the call of the macro.
          Note that if there are ''no'' parenthesis (like in, e.g.
          [[HelloWorld]]), then `args` is `None`.
        """
        return 'Hello World, args = ' + unicode(args)
    
    # Note that there's no need to HTML escape the returned data,
    # as the template engine (Genshi) will do it for us.

expand_macro details

expand_macro should return either a simple Python string which will be interpreted as HTML, or preferably a Markup object (use from trac.util.html import Markup). Markup(string) just annotates the string so the renderer will render the HTML string as-is with no escaping. You will also need to import Formatter using from trac.wiki import Formatter.

If your macro creates wiki markup instead of HTML, you can convert it to HTML like this:

  text = "whatever wiki markup you want, even containing other macros"
  # Convert Wiki markup to HTML, new style
  out = StringIO()
  Formatter(self.env, formatter.context).format(text, out)
  return Markup(out.getvalue())