Add binding event (#438)

* add binding_event

* Add specs for binding_event

lib/aasm/aasm.rb

@@ -159,6 +159,11 @@ private
       yield if block_given?
     end
 
+    binding_event = event.options[:binding_event]
+    if binding_event
+      __send__("#{binding_event}#{'!' if persist}")
+    end
+
     if persist_successful
       old_state.fire_callbacks(:after_exit, self,
         *process_args(event, aasm(state_machine_name).current_state, *args))

spec/models/simple_multiple_example.rb

@@ -27,4 +27,16 @@ class SimpleMultipleExample
       transitions :from => :processing, :to => :sleeping
     end
   end
+
+  aasm(:question) do
+    state :answered, :initial => true
+    state :asked
+
+    event :ask, :binding_event => :start do
+      transitions :from => :answered, :to => :asked
+    end
+    event :answer, :binding_event => :stop do
+      transitions :from => :asked, :to => :answered
+    end
+  end
 end

spec/unit/simple_multiple_example_spec.rb

@@ -60,4 +60,32 @@ describe 'state machine' do
     expect(SimpleMultipleExample::STATE_PROCESSING).to eq(:processing)
     expect(SimpleMultipleExample::STATE_RUNNING).to eq(:running)
   end
+
+  context 'triggers binding_events in bindind_state_machine' do
+    it 'does persist' do
+      expect(simple).to be_sleeping
+      expect(simple).to be_answered
+      expect(simple).to receive(:start!).and_call_original
+      simple.ask!
+      expect(simple).to be_asked
+      expect(simple).to be_processing
+      expect(simple).to receive(:stop!).and_call_original
+      simple.answer!
+      expect(simple).to be_sleeping
+      expect(simple).to be_answered
+    end
+
+    it 'does not persist' do
+      expect(simple).to be_sleeping
+      expect(simple).to be_answered
+      expect(simple).to receive(:start).and_call_original
+      simple.ask
+      expect(simple).to be_asked
+      expect(simple).to be_processing
+      expect(simple).to receive(:stop).and_call_original
+      simple.answer
+      expect(simple).to be_sleeping
+      expect(simple).to be_answered
+    end
+  end
 end