lib/moosex.rb in moosex-0.0.7 vs lib/moosex.rb in moosex-0.0.8

@@ -65,32 +65,32 @@
 
 				attr = MooseX::Attribute.new(attr_name, attr_options)
 
 				g = attr.generate_getter
 				
-	    		define_method attr.attr_symbol, &g
+	    	define_method attr.reader, &g
 	 
 	 			s = attr.generate_setter
 	 		
 	 			case attr.is 
 	 			when :rw 				
-					define_method "#{attr.attr_symbol}=", &s
+					define_method attr.writter, &s
 				
 				when :rwp
-					define_method "#{attr.attr_symbol}=", &s
+					define_method attr.writter, &s
 					
-					private "#{attr.attr_symbol}="
+					private attr.writter
 				end
 
 				__meta.add(attr)
 			end
 		end
 	end	
 	
 	class Attribute
 
-		attr_reader :attr_symbol, :is 
+		attr_reader :attr_symbol, :is, :reader, :writter, :lazy, :builder
 		DEFAULTS= { 
 			lazy: false,
 			clearer: false,
 			required: false, 
 			predicate: false,
@@ -104,11 +104,10 @@
 			is: lambda do |is, field_name| 
 				unless [:rw, :rwp, :ro, :lazy].include?(is)
 					raise "invalid value for field '#{field_name}' is '#{is}', must be one of :rw, :rwp, :ro or :lazy"  
 				end
 			end,
-			handles: lambda {|handles, field_name| true }, # TODO: add implementation
 		};
 
 		COERCE = {
 			is: lambda do |is, field_name| 
 				is.to_sym 
@@ -197,17 +196,42 @@
 				handles.map do |key,value|
 					{ key.to_sym => value.to_sym }
 				end.reduce({}) do |hash,e| 
 					hash.merge(e)
 				end
-			end,			
+			end,
+			reader: lambda do |reader, field_name|
+				reader.to_sym
+			end,
+			writter: lambda do |writter, field_name|
+				writter.to_sym
+			end,
+			builder: lambda do |builder, field_name|
+				unless builder.is_a? Proc
+					builder_method_name = builder.to_sym
+					builder = lambda do |object|
+						object.send(builder_method_name)
+					end
+				end
+
+				builder
+			end,
+			init_arg: lambda do |init_arg, field_name|
+				init_arg.to_sym
+			end,
 		};
 
 		def initialize(a, o)
 			# todo extract this to a framework, see issue #21 on facebook
-			o = DEFAULTS.merge(o)
 
+			o = DEFAULTS.merge({
+				reader: a,
+				writter: a.to_s.concat("=").to_sym,
+			  builder: "build_#{a}".to_sym,
+			  init_arg: a,
+			}).merge(o)
+
 			REQUIRED.each { |field| 
 				unless o.has_key?(field)
 					raise "field #{field} is required for Attribute #{a}" 
 				end
 			}
@@ -218,10 +242,18 @@
 			end
 			VALIDATE.each_pair do |field, validate|
 				return if ! o.has_key? field
 
 				validate.call(o[field], a)
+			end
+
+			if o[:is].eql? :lazy
+				o[:lazy] = true
+			end
+
+			unless o[:lazy]
+				o[:builder] = nil
 			end	
 
 			@attr_symbol = a
 			@is          = o[:is]
 			@isa         = o[:isa]
@@ -229,16 +261,19 @@
 			@required    = o[:required] 
 			@predicate   = o[:predicate]
 			@clearer     = o[:clearer]
 			@handles     = o[:handles]
 			@lazy        = o[:lazy]
+			@reader      = o[:reader]
+			@writter     = o[:writter]
+			@builder     = o[:builder]
+			@init_arg    = o[:init_arg]
 		end
 		
 		def init(object, args)
 			inst_variable_name = "@#{@attr_symbol}".to_sym
 			
-			setter = @attr_symbol.to_s.concat("=").to_sym
 			value  = nil
 
 			attr_symbol = @attr_symbol
 			@handles.each_pair do | method, target_method |
 				object.define_singleton_method method do |*args|
@@ -258,50 +293,66 @@
 						remove_instance_variable inst_variable_name
 					end
 				end
 			end
 
-			if args.has_key? @attr_symbol
-				value = args[ @attr_symbol ]
+			if args.has_key? @init_arg
+				value = args[ @init_arg ]
 			elsif @default
 				value = @default.call
 			elsif @required
 				raise "attr \"#{@attr_symbol}\" is required"
 			else
 				return
 			end
  
- 			if @is.eql? :ro
+ 			if @is.eql?(:ro) || @is.eql?(:lazy)
 
  				# TODO: remove redundancy
 
-				type_check = generate_type_check
+				type_check = @isa
 				type_check.call(value)
+
 				object.instance_variable_set inst_variable_name, value
 			
 			else
 
-				object.send( setter, value )
+				object.send( @writter, value )
 				
 			end	
 		end
 		
 		def generate_getter
 			inst_variable_name = "@#{@attr_symbol}".to_sym
-			Proc.new { instance_variable_get inst_variable_name }
+			
+			builder    = @builder
+			before_get = lambda {|object|  }
+
+			if @lazy
+				type_check = @isa
+
+				before_get = lambda do |object|
+					return if object.instance_variable_defined? inst_variable_name
+
+					value = builder.call(object)
+					type_check.call(value)
+
+					object.instance_variable_set(inst_variable_name, value)					
+				end
+			end
+
+			Proc.new do 
+				before_get.call(self)
+				instance_variable_get inst_variable_name 
+			end
 		end
 		
 		def generate_setter
 			inst_variable_name = "@#{@attr_symbol}".to_sym
-			type_check = generate_type_check
+			type_check = @isa
 			Proc.new  do |value| 
 				type_check.call(value)
 				instance_variable_set inst_variable_name, value
 			end
-		end
-		
-		def generate_type_check
-
-			return @isa
-		end			
+		end	
 	end
 end
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