1 files changed, 40 insertions, 0 deletions
diff --git a/activemodel/lib/active_model/state_machine/state_transition.rb b/activemodel/lib/active_model/state_machine/state_transition.rb
new file mode 100644
index 0000000000..f9df998ea4
--- /dev/null
+++ b/activemodel/lib/active_model/state_machine/state_transition.rb
@@ -0,0 +1,40 @@
+module ActiveModel
+  module StateMachine
+    class StateTransition
+      attr_reader :from, :to, :options
+
+      def initialize(opts)
+        @from, @to, @guard, @on_transition = opts[:from], opts[:to], opts[:guard], opts[:on_transition]
+        @options = opts
+      end
+
+      def perform(obj)
+        case @guard
+        when Symbol, String
+          obj.send(@guard)
+        when Proc
+          @guard.call(obj)
+        else
+          true
+        end
+      end
+      
+      def execute(obj, *args)
+        case @on_transition
+        when Symbol, String
+          obj.send(@on_transition, *args)
+        when Proc
+          @on_transition.call(obj, *args)
+        end
+      end
+
+      def ==(obj)
+        @from == obj.from && @to == obj.to
+      end
+
+      def from?(value)
+        @from == value
+      end
+    end
+  end
+end