lib/ohm/validations.rb in ohm-0.0.5 vs lib/ohm/validations.rb in ohm-0.0.6

@@ -1,17 +1,74 @@
 module Ohm
   module Validations
+    class Presenter
+      class UnhandledErrors < StandardError
+        attr :errors
+
+        def initialize(errors)
+          @errors = errors
+        end
+
+        def message
+          "Unhandled errors: #{errors.inspect}"
+        end
+      end
+
+      def initialize(errors)
+        @errors = errors
+        @unhandled = errors.dup
+        @output = []
+      end
+
+      def on(error, message = (block_given? ? yield : raise(ArgumentError)))
+        handle(error) do
+          @output << message
+        end
+      end
+
+      def ignore(error)
+        handle(error)
+      end
+
+      def present
+        yield(self)
+        raise UnhandledErrors.new(@unhandled) unless @unhandled.empty?
+        @output
+      end
+
+    protected
+
+      def handle(error)
+        if (errors = @errors.select {|e| error === e }).any?
+          @unhandled -= errors
+          yield(errors) if block_given?
+        end
+      end
+    end
+
+    class Errors < Array
+      attr_accessor :model
+
+      def initialize(model)
+        @model = model
+      end
+
+      def present(presenter = Presenter, &block)
+        presenter.new(model.errors).present(&block)
+      end
+    end
+
     def valid?
       errors.clear
       validate
       errors.empty?
     end
 
     def validate
     end
 
     def errors
-      @errors ||= []
+      @errors ||= Errors.new(self)
     end
 
   protected
 
     def assert_format(att, format)