From 899f2f01d999f90e3effd6d2d4062076bfd416b1 Mon Sep 17 00:00:00 2001
From: Sebastien Pierre <sebastien.pierre@gmail.com>
Date: Mon, 13 Feb 2012 15:26:45 -0500
Subject: [PATCH] Added @dispatch(prefix)

---
 src/cuisine.py | 72 ++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 52 insertions(+), 20 deletions(-)

diff --git a/src/cuisine.py b/src/cuisine.py
index b40004a..d3f7237 100644
--- a/src/cuisine.py
+++ b/src/cuisine.py
@@ -178,28 +178,60 @@ def sudo(*args, **kwargs):
 #
 # =============================================================================
 
-def dispatch(function):
-	"""Dispatches the current function to specific implementation. For instance
-	@dispatch("package_ensure", select="package_system").
+def dispatch(prefix=None):
+	"""Dispatches the current function to specific implementation. The `prefix`
+	parameter indicates the common option prefix, and the `option_select()`
+	function will determine the function suffix.
+	
+	For instance the package functions are defined like that:
+
+	{{{
+	@dispatch("package")
+	def package_ensure(...):
+		...
+	def package_ensure_apt(...):
+		...
+	def package_ensure_yum(...):
+		...
+	}}}
+	
+	and then when a user does
+
+	{{{
+	cuisine.option_select("package", "yum")
+	cuisine.package_ensure(...)
+	}}}
+
+	then the `dispatch` function will dispatch `package_ensure` to 
+	`package_ensure_yum`.
+
+	If your prefix is the first word of the function name before the
+	first `_` then you can simply use `@dispatch` without parameters.
 	"""
-	def wrapper(*args, **kwargs):
-		function_name = function.__name__
-		prefix        = function_name.split("_")[0]
-		select        = fabric.api.env.get("option_" + prefix)
-		assert select, "No option defined for: %s, call select_%s(<YOUR OPTION>) to set it" % (prefix, prefix)
-		function_name = function.__name__ + "_" + select
-		specific      = eval(function_name)
-		if specific:
-			if type(specific) == types.FunctionType:
-				return specific(*args, **kwargs)
+	def dispatch_wrapper(function, prefix=prefix):
+		def wrapper(*args, **kwargs):
+			function_name = function.__name__
+			_prefix       = prefix or function_name.split("_")[0]
+			select        = fabric.api.env.get("option_" + _prefix)
+			assert select, "No option defined for: %s, call select_%s(<YOUR OPTION>) to set it" % (_prefix, prefix)
+			function_name = function.__name__ + "_" + select
+			specific      = eval(function_name)
+			if specific:
+				if type(specific) == types.FunctionType:
+					return specific(*args, **kwargs)
+				else:
+					raise Exception("Function expected for: " + function_name)
 			else:
-				raise Exception("Function expected for: " + function_name)
-		else:
-			raise Exception("Function variant not defined: " + function_name)
-	# We copy name and docstring
-	wrapper.__name__ = function.__name__
-	wrapper.__doc__  = function.__doc__
-	return wrapper
+				raise Exception("Function variant not defined: " + function_name)
+		# We copy name and docstring
+		wrapper.__name__ = function.__name__
+		wrapper.__doc__  = function.__doc__
+		return wrapper
+	if type(prefix) == types.FunctionType:
+		return dispatch_wrapper(prefix, None)
+	else:
+		return dispatch_wrapper
+
 
 # =============================================================================
 #