Changes between Version 1 and Version 2 of WikiMacros

Timestamp:

2020-10-21T13:53:03+13:00 (4 years ago)

Author:

trac

Comment:

--

WikiMacros

@@ -1 @@
-=  Wiki Macros =
-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.
+= Trac Macros
 
-Another kind of macros are WikiProcessors. They typically deal with alternate markup formats and representation of larger blocks of information (like source code highlighting).
+[[PageOutline(2-5,Contents,pullout)]]
 
-== Using Macros ==
-Macro calls are enclosed in two ''square brackets''. Like Python functions, macros can also have arguments, a comma separated list within parentheses. 
+'''Trac macros''' extend Trac with custom functionality. Macros are a special type of plugin and are written in Python. A macro generates HTML in any context supporting WikiFormatting.
 
-=== Examples ===
+The macro syntax is `[[macro-name(optional-arguments)]]`.
+
+'''WikiProcessors''' are another kind of macro, commonly used for source code highlighting using a processor like `!#python` or `!#apache`:
 
 {{{
- [[Timestamp]]
+{{{#!wiki-processor-name
+...
 }}}
-Display:
- [[Timestamp]]
+}}}
 
-{{{
- [[HelloWorld(Testing)]]
+== Using Macros
+
+Macro calls are enclosed in double-square brackets `[[..]]`. Like Python functions macros can have arguments, which take the form of a comma separated list within parentheses `[[..(,)]]`. A common macro used is a list of the 3 most recent changes to a wiki page, or here, for example, all wiki pages starting with 'Trac':
+
+||= Wiki Markup =||= Display =||
+{{{#!td
+  {{{
+  [[RecentChanges(Trac,3)]]
+  }}}
 }}}
-Display:
- [[HelloWorld(Testing)]]
+{{{#!td style="padding-left: 2em;"
+[[RecentChanges(Trac,3)]]
+}}}
 
-== Available Macros ==
+=== Getting Detailed Help
 
-''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].''
+The list of available macros and the full help can be obtained using the !MacroList macro, see [#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?]]`.
+
+== Available Macros
 
 [[MacroList]]
 
-== Macros from around the world ==
+== Contributed macros
 
-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.
+The [https://trac-hacks.org/ Trac Hacks] site provides a large collection of macros and other Trac [TracPlugins plugins] contributed by the Trac community. If you are looking for new macros, or have written one that you would like to share, please visit that site.
 
-== Developing Custom Macros ==
-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.
+== Developing Custom Macros
 
-It's easiest to learn from an example:
-{{{
-#!python
-# MyMacro.py -- The world's simplest macro
+Macros, like Trac itself, are written in the [https://python.org/ Python programming language] and are a type of [TracPlugins plugin].
 
-def execute(hdf, args, env):
-    return "Hello World called with args: %s" % args
+Here are 2 simple examples showing how to create a Macro. For more information about developing macros, see the [trac:TracDev development resources] and [trac:browser:branches/1.4-stable/sample-plugins sample-plugins].
+
+=== Macro without arguments
+
+To test the following code, copy it to `timestamp_sample.py` in the TracEnvironment's `plugins/` directory.
+
+{{{#!python
+from trac.util.datefmt import datetime_now, format_datetime, utc
+from trac.util.html import tag
+from trac.wiki.macros import WikiMacroBase
+
+class TimestampMacro(WikiMacroBase):
+    _description = "Inserts the current time (in seconds) into the wiki page."
+
+    def expand_macro(self, formatter, name, content, args=None):
+        t = datetime_now(utc)
+        return tag.strong(format_datetime(t, '%c'))
 }}}
 
-You can also use the environment (`env`) object, for example to access configuration data and the database, for example:
-{{{
-#!python
-def execute(hdf, txt, env):
-    return env.config.get('trac', 'repository_dir')
+=== Macro with arguments
+
+To test the following code, copy it to `helloworld_sample.py` in the TracEnvironment's `plugins/` directory.
+
+{{{#!python
+from trac.util.translation import cleandoc_
+from trac.wiki.macros import WikiMacroBase
+
+class HelloWorldMacro(WikiMacroBase):
+    _description = cleandoc_(
+    """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).
+    """)
+
+    def expand_macro(self, formatter, name, content, args=None):
+        """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'`),
+        `content` 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 `content` is `None`.
+        `args` will contain a dictionary of arguments when called using the
+          Wiki processor syntax and will be `None` if called using the
+          macro syntax.
+        """
+        return 'Hello World, content = ' + unicode(content)
 }}}
 
-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.
+Note that `expand_macro` optionally takes a 4^th^ parameter ''`args`''. When the macro is called as a [WikiProcessors WikiProcessor], it is 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. When called as a macro, `args` is `None`.
 
-For more information about developing macros, see the [http://projects.edgewall.com/trac/wiki/TracDev development resources] on the main project site.
+For example, when writing:
+{{{
+{{{#!HelloWorld style="polite" -silent verbose
+<Hello World!>
+}}}
 
-----
-See also:  WikiProcessors, WikiFormatting, TracGuide
+{{{#!HelloWorld
+<Hello World!>
+}}}
+
+[[HelloWorld(<Hello World!>)]]
+}}}
+
+One should get:
+{{{
+Hello World, text = <Hello World!>, args = {'style': u'polite', 'silent': False, 'verbose': True}
+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 yourself (using `return Markup.escape(result)`), or if this is indeed HTML, wrap it in a Markup object: `return Markup(result)` (`from trac.util.html import Markup`).
+
+You can also recursively use a wiki formatter to process the `content` as wiki markup:
+
+{{{#!python
+from trac.wiki.formatter import format_to_html
+from trac.wiki.macros import WikiMacroBase
+
+class HelloWorldMacro(WikiMacroBase):
+    def expand_macro(self, formatter, name, content, args):
+        content = "any '''wiki''' markup you want, even containing other macros"
+        # Convert Wiki markup to HTML
+        return format_to_html(self.env, formatter.context, content)
+}}}