presenter_view.rb in prospecto-0.2.0

- old
+ new

@@ -1,11 +1,15 @@
+require "set"
+
 module Prospecto
   class PresenterView
     def initialize(args={})
       args.each do |name, value|
         if respond_to? name
           instance_variable_set("@#{name}", value)
+        elsif self.class.__delegates.include?(name)
+          __delegates << value
         else
           # Stop everything there is a design problem.
           raise ArgumentError.new("Unknown property '#{name}' for class '#{self.class.name}'.")
         end
       end
@@ -13,24 +17,34 @@
 
     def method_missing(name, *args, &block)
       if property_name = self.class.__properties.find{|m| name.to_s.start_with? "#{m}_"}
         field_name = name.to_s.sub("#{property_name}_", "")
         self.send(property_name).send(field_name)
+      elsif delegate_obj = __delegates.find{|d| d.respond_to? name}
+        delegate_obj.send(name)
       else
         super
       end
     end
 
+    def __delegates
+      @__delegates ||= Set.new
+    end
+
     class << self
       # "Presents" means a member will be reflected out to the view. Use of presents should be
       # limited to very special cases.
       alias :presents :attr_reader
 
       def __properties
-        @__properties ||= []
+        @__properties ||= Set.new
       end
 
+      def __delegates
+        @__delegates ||= Set.new
+      end
+
       # Accepts means the view uses the member internally, but it is not available
       # outside the class.
       def accepts(*args)
         args.each do |name|
           define_method name do
@@ -45,9 +59,16 @@
       def proxies(*args)
         args.each do |name|
           __properties << name
         end
         accepts(*args)
+      end
+
+      # Decorates means that properties of the object will be available directly on the presenter.
+      def decorates(*args)
+        args.each do |name|
+          __delegates << name
+        end
       end
     end
   end
 end