Changes between Version 2 and Version 3 of WikiMacros


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Timestamp:
Feb 22, 2011, 12:40:16 AM (8 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
     
    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.
    810
    9 === Examples ===
     11Macro calls are enclosed in two ''square brackets''. Like Python functions, macros can also have arguments, a comma separated list within parentheses.
    1012
    11 {{{
    12  [[Timestamp]]
     13=== Getting Detailed Help ===
     14The list of available macros and the full help can be obtained using the !MacroList macro, as seen [#AvailableMacros below].
     15
     16A brief list can be obtained via ![[MacroList(*)]] or ![[?]].
     17
     18Detailed help on a specific macro can be obtained by passing it as an argument to !MacroList, e.g. ![[MacroList(MacroList)]], or, more conveniently, by appending a question mark (?) to the macro's name, like in ![[MacroList?]].
     19
     20
     21
     22=== Example ===
     23
     24A list of 3 most recently changed wiki pages starting with 'Trac':
     25
     26||= Wiki Markup =||= Display =||
     27{{{#!td
     28  {{{
     29  [[RecentChanges(Trac,3)]]
     30  }}}
    1331}}}
    14 Display:
    15  [[Timestamp]]
    16 
    17 {{{
    18  [[HelloWorld(Testing)]]
     32{{{#!td style="padding-left: 2em;"
     33[[RecentChanges(Trac,3)]]
    1934}}}
    20 Display:
    21  [[HelloWorld(Testing)]]
     35|-----------------------------------
     36{{{#!td
     37  {{{
     38  [[RecentChanges?(Trac,3)]]
     39  }}}
     40}}}
     41{{{#!td style="padding-left: 2em;"
     42[[RecentChanges?(Trac,3)]]
     43}}}
     44|-----------------------------------
     45{{{#!td
     46  {{{
     47  [[?]]
     48  }}}
     49}}}
     50{{{#!td style="padding-left: 2em; font-size: 80%"
     51[[?]]
     52}}}
    2253
    2354== Available Macros ==
     
    3263
    3364== 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.
     65Macros, like Trac itself, are written in the [http://python.org/ Python programming language] and are developed as part of TracPlugins.
    3566
    36 It's easiest to learn from an example:
     67For more information about developing macros, see the [trac:TracDev development resources] on the main project site.
     68
     69
     70Here are 2 simple examples showing how to create a Macro with Trac 0.11.
     71
     72Also, 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.
     73
     74=== Macro without arguments ===
     75To test the following code, you should saved it in a `timestamp_sample.py` file located in the TracEnvironment's `plugins/` directory.
    3776{{{
    3877#!python
    39 # MyMacro.py -- The world's simplest macro
     78from datetime import datetime
     79# Note: since Trac 0.11, datetime objects are used internally
    4080
    41 def execute(hdf, args, env):
    42     return "Hello World called with args: %s" % args
     81from genshi.builder import tag
     82
     83from trac.util.datefmt import format_datetime, utc
     84from trac.wiki.macros import WikiMacroBase
     85
     86class TimeStampMacro(WikiMacroBase):
     87    """Inserts the current time (in seconds) into the wiki page."""
     88
     89    revision = "$Rev$"
     90    url = "$URL$"
     91
     92    def expand_macro(self, formatter, name, text):
     93        t = datetime.now(utc)
     94        return tag.b(format_datetime(t, '%c'))
    4395}}}
    4496
    45 You can also use the environment (`env`) object, for example to access configuration data and the database, for example:
     97=== Macro with arguments ===
     98To test the following code, you should saved it in a `helloworld_sample.py` file located in the TracEnvironment's `plugins/` directory.
    4699{{{
    47100#!python
    48 def execute(hdf, txt, env):
    49     return env.config.get('trac', 'repository_dir')
     101from genshi.core import Markup
     102
     103from trac.wiki.macros import WikiMacroBase
     104
     105class HelloWorldMacro(WikiMacroBase):
     106    """Simple HelloWorld macro.
     107
     108    Note that the name of the class is meaningful:
     109     - it must end with "Macro"
     110     - what comes before "Macro" ends up being the macro name
     111
     112    The documentation of the class (i.e. what you're reading)
     113    will become the documentation of the macro, as shown by
     114    the !MacroList macro (usually used in the WikiMacros page).
     115    """
     116
     117    revision = "$Rev$"
     118    url = "$URL$"
     119
     120    def expand_macro(self, formatter, name, text, args):
     121        """Return some output that will be displayed in the Wiki content.
     122
     123        `name` is the actual name of the macro (no surprise, here it'll be
     124        `'HelloWorld'`),
     125        `text` is the text enclosed in parenthesis at the call of the macro.
     126          Note that if there are ''no'' parenthesis (like in, e.g.
     127          [[HelloWorld]]), then `text` is `None`.
     128        `args` are the arguments passed when HelloWorld is called using a
     129        `#!HelloWorld` code block.
     130        """
     131        return 'Hello World, text = %s, args = %s' % \
     132            (Markup.escape(text), Markup.escape(repr(args)))
     133
    50134}}}
    51135
    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.
     136Note that `expand_macro` optionally takes a 4^th^ parameter ''`args`''. When the macro is called as a [WikiProcessors WikiProcessor], it's also possible to pass `key=value` [WikiProcessors#UsingProcessors processor parameters]. If given, those are stored in a dictionary and passed in this extra `args` parameter. On the contrary, when called as a macro, `args` is  `None`. (''since 0.12'').
    53137
    54 For more information about developing macros, see the [http://projects.edgewall.com/trac/wiki/TracDev development resources] on the main project site.
     138For example, when writing:
     139{{{
     140{{{#!HelloWorld style="polite"
     141<Hello World!>
     142}}}
    55143
    56 ----
    57 See also:  WikiProcessors, WikiFormatting, TracGuide
     144{{{#!HelloWorld
     145<Hello World!>
     146}}}
     147
     148[[HelloWorld(<Hello World!>)]]
     149}}}
     150One should get:
     151{{{
     152Hello World, text = <Hello World!> , args = {'style': u'polite'}
     153Hello World, text = <Hello World!> , args = {}
     154Hello World, text = <Hello World!> , args = None
     155}}}
     156
     157Note that the return value of `expand_macro` is '''not''' HTML escaped. Depending on the expected result, you should escape it by yourself (using `return Markup.escape(result)`) or, if this is indeed HTML, wrap it in a Markup object (`return Markup(result)`) with `Markup` coming from Genshi, (`from genshi.core import Markup`). 
     158
     159You can also recursively use a wiki Formatter (`from trac.wiki import Formatter`) to process the `text` as wiki markup, for example by doing:
     160
     161{{{
     162#!python
     163from genshi.core import Markup
     164from trac.wiki.macros import WikiMacroBase
     165from trac.wiki import Formatter
     166import StringIO
     167
     168class HelloWorldMacro(WikiMacroBase):
     169        def expand_macro(self, formatter, name, text, args):
     170                text = "whatever '''wiki''' markup you want, even containing other macros"
     171                # Convert Wiki markup to HTML, new style
     172                out = StringIO.StringIO()
     173                Formatter(self.env, formatter.context).format(text, out)
     174                return Markup(out.getvalue())
     175}}}