Changes between Initial Version and Version 1 of WikiMacros

Timestamp:

06/16/11 14:29:48 (14 years ago)

Author:

trac

Comment:

--

WikiMacros

@@ +1 @@
+= Trac Macros =
+
+[[PageOutline]]
+
+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.
+
+=== Getting Detailed Help ===
+The list of available macros and the full help can be obtained using the !MacroList macro, as seen [#AvailableMacros below].
+
+A brief list can be obtained via ![[MacroList(*)]] or ![[?]].
+
+Detailed 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?]].
+
+
+
+=== Example ===
+
+A list of 3 most recently changed wiki pages starting with 'Trac':
+
+||= Wiki Markup =||= Display =||
+{{{#!td
+  {{{
+  [[RecentChanges(Trac,3)]]
+  }}}
+}}}
+{{{#!td style="padding-left: 2em;"
+[[RecentChanges(Trac,3)]]
+}}}
+|-----------------------------------
+{{{#!td
+  {{{
+  [[RecentChanges?(Trac,3)]]
+  }}}
+}}}
+{{{#!td style="padding-left: 2em;"
+[[RecentChanges?(Trac,3)]]
+}}}
+|-----------------------------------
+{{{#!td
+  {{{
+  [[?]]
+  }}}
+}}}
+{{{#!td style="padding-left: 2em; font-size: 80%"
+[[?]]
+}}}
+
+== 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 [wiki:TracModPython mod_python].''
+
+[[MacroList]]
+
+== Macros from around the world ==
+
+The [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.
+
+== Developing Custom Macros ==
+Macros, like Trac itself, are written in the [http://python.org/ Python programming language] and are developed as part of TracPlugins.
+
+For more information about developing macros, see the [trac:TracDev development resources] on the main project site.
+
+
+Here are 2 simple examples showing how to create a Macro with Trac 0.11. 
+
+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.
+
+=== Macro without arguments ===
+To test the following code, you should saved it in a `timestamp_sample.py` file located in the TracEnvironment's `plugins/` directory.
+{{{
+#!python
+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, text):
+        t = datetime.now(utc)
+        return tag.b(format_datetime(t, '%c'))
+}}}
+
+=== Macro with arguments ===
+To test the following code, you should saved it in a `helloworld_sample.py` file located in the TracEnvironment's `plugins/` directory.
+{{{
+#!python
+from genshi.core import Markup
+
+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, text, 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'`),
+        `text` 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 `text` is `None`.
+        `args` are the arguments passed when HelloWorld is called using a
+        `#!HelloWorld` code block.
+        """
+        return 'Hello World, text = %s, args = %s' % \
+            (Markup.escape(text), Markup.escape(repr(args)))
+
+}}}
+
+Note 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'').
+
+For example, when writing:
+{{{
+{{{#!HelloWorld style="polite"
+<Hello World!>
+}}}
+
+{{{#!HelloWorld
+<Hello World!>
+}}}
+
+[[HelloWorld(<Hello World!>)]]
+}}}
+One should get:
+{{{
+Hello World, text = <Hello World!> , args = {'style': u'polite'}
+Hello World, text = <Hello World!> , args = {}
+Hello World, text = <Hello World!> , args = None
+}}}
+
+Note 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`).  
+
+You can also recursively use a wiki Formatter (`from trac.wiki import Formatter`) to process the `text` as wiki markup, for example by doing:
+
+{{{
+#!python
+from genshi.core import Markup
+from trac.wiki.macros import WikiMacroBase
+from trac.wiki import Formatter
+import StringIO
+
+class HelloWorldMacro(WikiMacroBase):
+        def expand_macro(self, formatter, name, text, args):
+                text = "whatever '''wiki''' markup you want, even containing other macros"
+                # Convert Wiki markup to HTML, new style
+                out = StringIO.StringIO()
+                Formatter(self.env, formatter.context).format(text, out)
+                return Markup(out.getvalue())
+}}}