Changes between Version 1 and Version 2 of WikiMacros


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Timestamp:
09/10/09 19:34:25 (15 years ago)
Author:
trac
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  • WikiMacros

    v1 v2  
    1 = Trac Macros =
    2 
    3 [[PageOutline]]
    4 
     1=  Wiki Macros =
    52Trac 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.
    63
    … …  
    107Macro calls are enclosed in two ''square brackets''. Like Python functions, macros can also have arguments, a comma separated list within parentheses.
    118
    12 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.
    13 
    14 === Example ===
    15 
    16 A list of 3 most recently changed wiki pages starting with 'Trac':
     9=== Examples ===
    1710
    1811{{{
    19  [[RecentChanges(Trac,3)]]
     12 [[Timestamp]]
    2013}}}
     14Display:
     15 [[Timestamp]]
    2116
     17{{{
     18 [[HelloWorld(Testing)]]
     19}}}
    2220Display:
    23  [[RecentChanges(Trac,3)]]
     21 [[HelloWorld(Testing)]]
    2422
    2523== Available Macros ==
    … …  
    3432
    3533== Developing Custom Macros ==
    36 Macros, like Trac itself, are written in the [http://python.org/ Python programming language].
     34Macros, like Trac itself, are written in the [http://www.python.org/ Python programming language]. They are very simple modules, identified by the filename and should contain a single `execute()` function. Trac will display the returned data inserted into the HTML representation of the Wiki page where the macro is called.
    3735
    38 For more information about developing macros, see the [trac:TracDev development resources] on the main project site.
    39 
    40 
    41 == Implementation ==
    42 
    43 Here are 2 simple examples showing how to create a Macro with Trac 0.11.
    44 
    45 Also, have a look at [trac:source:tags/trac-0.11/sample-plugins/Timestamp.py Timestamp.py] for an example that shows the difference between old style and new style macros and at the [trac:source:tags/trac-0.11/wiki-macros/README macros/README] which provides a little more insight about the transition.
    46 
    47 === Macro without arguments ===
    48 It should be saved as `TimeStamp.py` as Trac will use the module name as the Macro name
     36It's easiest to learn from an example:
    4937{{{
    5038#!python
    51 from datetime import datetime
    52 # Note: since Trac 0.11, datetime objects are used internally
     39# MyMacro.py -- The world's simplest macro
    5340
    54 from genshi.builder import tag
    55 
    56 from trac.util.datefmt import format_datetime, utc
    57 from trac.wiki.macros import WikiMacroBase
    58 
    59 class TimeStampMacro(WikiMacroBase):
    60     """Inserts the current time (in seconds) into the wiki page."""
    61 
    62     revision = "$Rev$"
    63     url = "$URL$"
    64 
    65     def expand_macro(self, formatter, name, args):
    66         t = datetime.now(utc)
    67         return tag.b(format_datetime(t, '%c'))
     41def execute(hdf, args, env):
     42    return "Hello World called with args: %s" % args
    6843}}}
    6944
    70 === Macro with arguments ===
    71 It should be saved as `HelloWorld.py` (in the plugins/ directory) as Trac will use the module name as the Macro name
     45You can also use the environment (`env`) object, for example to access configuration data and the database, for example:
    7246{{{
    7347#!python
    74 from trac.wiki.macros import WikiMacroBase
    75 
    76 class HelloWorldMacro(WikiMacroBase):
    77     """Simple HelloWorld macro.
    78 
    79     Note that the name of the class is meaningful:
    80      - it must end with "Macro"
    81      - what comes before "Macro" ends up being the macro name
    82 
    83     The documentation of the class (i.e. what you're reading)
    84     will become the documentation of the macro, as shown by
    85     the !MacroList macro (usually used in the WikiMacros page).
    86     """
    87 
    88     revision = "$Rev$"
    89     url = "$URL$"
    90 
    91     def expand_macro(self, formatter, name, args):
    92         """Return some output that will be displayed in the Wiki content.
    93 
    94         `name` is the actual name of the macro (no surprise, here it'll be
    95         `'HelloWorld'`),
    96         `args` is the text enclosed in parenthesis at the call of the macro.
    97           Note that if there are ''no'' parenthesis (like in, e.g.
    98           [[HelloWorld]]), then `args` is `None`.
    99         """
    100         return 'Hello World, args = ' + unicode(args)
    101    
    102     # Note that there's no need to HTML escape the returned data,
    103     # as the template engine (Genshi) will do it for us.
     48def execute(hdf, txt, env):
     49    return env.config.get('trac', 'repository_dir')
    10450}}}
    10551
     52Note that since version 0.9, wiki macros can also be written as TracPlugins. This gives them some capabilities that “classic” macros do not have, such as being able to directly access the HTTP request.
    10653
    107 === {{{expand_macro}}} details ===
    108 {{{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}}}.
     54For more information about developing macros, see the [http://projects.edgewall.com/trac/wiki/TracDev development resources] on the main project site.
    10955
    110 If your macro creates wiki markup instead of HTML, you can convert it to HTML like this:
    111 
    112 {{{
    113 #!python
    114   text = "whatever wiki markup you want, even containing other macros"
    115   # Convert Wiki markup to HTML, new style
    116   out = StringIO()
    117   Formatter(self.env, formatter.context).format(text, out)
    118   return Markup(out.getvalue())
    119 }}}
     56----
     57See also:  WikiProcessors, WikiFormatting, TracGuide