Changes between Version 2 and Version 3 of WikiMacros


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Timestamp:
Jan 25, 2009 10:55:11 AM (11 years ago)
Author:
trac
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  • WikiMacros

    v2 v3  
    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 
    4 Another kind of macros are WikiProcessors. They typically deal with alternate markup formats and representation of larger blocks of information (like source code highlighting). See also: WikiProcessors. 
     7Another kind of macros are WikiProcessors. They typically deal with alternate markup formats and representation of larger blocks of information (like source code highlighting). 
    58 
    69== Using Macros == 
    7 Macro calls are enclosed in two ''square brackets''. Like python functions, macros can also have arguments, a comma separated list within parentheses.  
     10Macro 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 == 
    2426 
    25 Macros are still a relatively new feature, and the list of available (and distributed) macros is  
    26 admittedly not very impressive. In future Trac releases, we hope to build a library of useful macros, and will of course happily include contributed macros (see below).  
     27''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 [wiki:TracModPython mod_python].'' 
    2728 
    2829[[MacroList]] 
    2930 
    3031== Macros from around the world == 
    31 The [http://projects.edgewall.com/trac/ Trac Project] has a section dedicated to user-contributed macros, [wiki:MacroBazaar 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 [wiki:MacroBazaar MacroBazaar] wiki page. 
    3232 
    33   http://projects.edgewall.com/trac/wiki/MacroBazaar 
     33The [http://trac-hacks.org/ Trac Hacks] site provides a wide collection of macros and other Trac [TracPlugins 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. 
     34 
     35== Developing Custom Macros == 
     36Macros, like Trac itself, are written in the [http://python.org/ Python programming language]. 
     37 
     38For more information about developing macros, see the [wiki:TracDev development resources] on the main project site. 
    3439 
    3540 
    36 ---- 
     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 
     47{{{ 
     48#!python 
     49from datetime import datetime 
     50# Note: since Trac 0.11, datetime objects are used internally 
     51 
     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')) 
     66}}} 
     67 
     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 
     70{{{ 
     71#!python 
     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. 
     102}}} 
    37103 
    38104 
    39 == Developing New Macros == 
    40 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 ''entry point'' function. Trac will display the returned data inserted into the HTML where the macro was called. 
     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}}}. 
    41107 
    42 It's easiest to learn from an example: 
     108If your macro creates wiki markup instead of HTML, you can convert it to HTML like this: 
     109 
    43110{{{ 
    44111#!python 
    45 # MyMacro.py -- The world's simplest macro 
    46  
    47 def execute(hdf, args, env): 
    48     return "Hello World called with args: %s" % args 
     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()) 
    49117}}} 
    50  
    51 === Advanced Topics: Template-enabled Macros === 
    52 For advanced uses, macros can also render structured output in HDF, to be rendered to HTML using clearsilver templates - like most Trac output. In short, this allows more generic and well-designed advanced macros. 
    53  
    54 Macros gain direct access to the main HDF tree, and are free to manipulate it.  
    55  
    56 Example: 
    57 {{{ 
    58 #!python 
    59 def execute(hdf, args, env): 
    60     # Currently hdf is set only when the macro is called 
    61     # from a wiki page. 
    62     if hdf: 
    63         hdf.setValue('wiki.macro.greeting', 'Hello World') 
    64          
    65     # args will be null if the macro is called without parentheses. 
    66     args = args or 'No arguments' 
    67     return 'Hello World, args = ' + args 
    68 }}} 
    69  
    70 You can also use the environment (env) object to access configuration data. 
    71  
    72 Example. 
    73 {{{ 
    74 #!python 
    75 def execute(hdf, txt, env): 
    76     return env.get_config('trac', 'repository_dir') 
    77 }}} 
    78  
    79 Here is information on the different WikiMacroObjects. 
    80  
    81 ---- 
    82 See also:  WikiProcessors, WikiFormatting, TracGuide, WikiMacroObjects