Changes between Version 1 and Version 2 of WikiMacros

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Timestamp:
02/01/11 23:15:03 (4 years ago)
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trac (IP: 127.0.0.1)
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  • WikiMacros

    v1 v2  
    1 =  Wiki Macros = 
     1= Trac Macros = 
     2 
     3[[PageOutline]] 
     4 
    25Trac 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. 
    36 
     
    710Macro calls are enclosed in two ''square brackets''. Like Python functions, macros can also have arguments, a comma separated list within parentheses.  
    811 
    9 === Examples === 
     12Trac 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 
     16A list of 3 most recently changed wiki pages starting with 'Trac': 
    1017 
    1118{{{ 
    12  [[Timestamp]] 
     19 [[RecentChanges(Trac,3)]] 
    1320}}} 
     21 
    1422Display: 
    15  [[Timestamp]] 
    16  
    17 {{{ 
    18  [[HelloWorld(Testing)]] 
    19 }}} 
    20 Display: 
    21  [[HelloWorld(Testing)]] 
     23 [[RecentChanges(Trac,3)]] 
    2224 
    2325== Available Macros == 
     
    3234 
    3335== Developing Custom Macros == 
    34 Macros, 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. 
     36Macros, like Trac itself, are written in the [http://python.org/ Python programming language]. 
    3537 
    36 It's easiest to learn from an example: 
     38For more information about developing macros, see the [wiki:TracDev development resources] on the main project site. 
     39 
     40 
     41== Implementation == 
     42 
     43Here are 2 simple examples on how to create a Macro with [wiki:0.11 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. 
     44 
     45=== Macro without arguments === 
     46It should be saved as `TimeStamp.py` as Trac will use the module name as the Macro name 
    3747{{{ 
    3848#!python 
    39 # MyMacro.py -- The world's simplest macro 
     49from datetime import datetime 
     50# Note: since Trac 0.11, datetime objects are used internally 
    4051 
    41 def execute(hdf, args, env): 
    42     return "Hello World called with args: %s" % args 
     52from genshi.builder import tag 
     53 
     54from trac.util.datefmt import format_datetime, utc 
     55from trac.wiki.macros import WikiMacroBase 
     56 
     57class TimestampMacro(WikiMacroBase): 
     58    """Inserts the current time (in seconds) into the wiki page.""" 
     59 
     60    revision = "$Rev$" 
     61    url = "$URL$" 
     62 
     63    def expand_macro(self, formatter, name, args): 
     64        t = datetime.now(utc) 
     65        return tag.b(format_datetime(t, '%c')) 
    4366}}} 
    4467 
    45 You can also use the environment (`env`) object, for example to access configuration data and the database, for example: 
     68=== Macro with arguments === 
     69It should be saved as `HelloWorld.py` (in the plugins/ directory) as Trac will use the module name as the Macro name 
    4670{{{ 
    4771#!python 
    48 def execute(hdf, txt, env): 
    49     return env.config.get('trac', 'repository_dir') 
     72from trac.wiki.macros import WikiMacroBase 
     73 
     74class HelloWorldMacro(WikiMacroBase): 
     75    """Simple HelloWorld macro. 
     76 
     77    Note that the name of the class is meaningful: 
     78     - it must end with "Macro" 
     79     - what comes before "Macro" ends up being the macro name 
     80 
     81    The documentation of the class (i.e. what you're reading) 
     82    will become the documentation of the macro, as shown by 
     83    the !MacroList macro (usually used in the WikiMacros page). 
     84    """ 
     85 
     86    revision = "$Rev$" 
     87    url = "$URL$" 
     88 
     89    def expand_macro(self, formatter, name, args): 
     90        """Return some output that will be displayed in the Wiki content. 
     91 
     92        `name` is the actual name of the macro (no surprise, here it'll be 
     93        `'HelloWorld'`), 
     94        `args` is the text enclosed in parenthesis at the call of the macro. 
     95          Note that if there are ''no'' parenthesis (like in, e.g. 
     96          [[HelloWorld]]), then `args` is `None`. 
     97        """ 
     98        return 'Hello World, args = ' + unicode(args) 
     99     
     100    # Note that there's no need to HTML escape the returned data, 
     101    # as the template engine (Genshi) will do it for us. 
    50102}}} 
    51103 
    52 Note 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. 
    53104 
    54 For more information about developing macros, see the [http://projects.edgewall.com/trac/wiki/TracDev development resources] on the main project site. 
     105=== {{{expand_macro}}} details === 
     106{{{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}}}. 
    55107 
    56 ---- 
    57 See also:  WikiProcessors, WikiFormatting, TracGuide 
     108If your macro creates wiki markup instead of HTML, you can convert it to HTML like this: 
     109 
     110{{{ 
     111#!python 
     112  text = "whatever wiki markup you want, even containing other macros" 
     113  # Convert Wiki markup to HTML, new style 
     114  out = StringIO() 
     115  Formatter(self.env, formatter.context).format(text, out) 
     116  return Markup(out.getvalue()) 
     117}}}