added Invoker mixin

middleclass/mixins/Invoker.lua

@@ -0,0 +1,38 @@
+-----------------------------------------------------------------------------------
+-- Invoker.lua
+-- Enrique García ( enrique.garcia.cota [AT] gmail [DOT] com ) - 4 Mar 2010
+-- Helper function that simplifies method invocation via method names or functions
+-----------------------------------------------------------------------------------
+
+--[[ Usage:
+
+  require 'middleclass.mixins.Invoker' -- or 'middleclass.init'
+
+  MyClass = class('MyClass')
+  MyClass:includes(Invoker)
+  function MyClass:foo(x,y) print('foo executed with params', x, y) end
+
+  local obj = MyClass:new()
+
+  obj:invoke('foo', 1,2) -- foo executed with params 1 2
+  obj:invoke( function(self, x, y)
+    print('nameless function executed with params', x, y)
+  , 3, 4) -- nameless function executed with params 3, 4
+  
+  Note that the function first parameter will allways be self
+]]
+
+assert(Object~=nil and class~=nil, 'MiddleClass not detected. Please require it before using Beholder')
+
+Invoker = {
+
+  invoke = function(self, methodOrName, ...)
+    local method = methodOrName
+    if(type(methodOrName)=='string') then method = self[methodOrName] end
+    assert(type(method)=='function', 'Invoker:invoke requires a function or function name')
+    return method(self, ...)
+  end
+
+}
+
+

spec/Invoker_spec.lua

@@ -0,0 +1,26 @@
+require('middleclass.init')
+
+context( 'Invoker', function()
+
+  local MyClass = class('MyClass')
+  MyClass:include(Invoker)
+  function MyClass:foo(x,y) return 'foo ' .. tostring(x) .. ', ' .. tostring(y) end
+  
+  local obj = MyClass:new()
+  
+  test('It should work with method names', function()
+    assert_equal(obj:invoke('foo', 1, 2), 'foo 1, 2')
+  end)
+  
+  test('It should work with implicit functions', function()
+    assert_equal(
+      obj:invoke(
+        function(self, x, y) return 'bar '.. tostring(x) .. ', ' .. tostring(y) end,
+        3,
+        4
+      ),
+      'bar 3, 4'
+    )
+  end)
+
+end)