you may now disable whiny transactions (using the new dsl)

lib/aasm/aasm.rb

@@ -197,7 +197,11 @@ def aasm_fire_event(name, options, *args)
           self.aasm_event_failed(name, old_state.name)
         end
 
-        raise AASM::InvalidTransition, "Event '#{event.name}' cannot transition from '#{self.aasm_current_state}'"
+        if AASM::StateMachine[self.class].config.whiny_transitions
+          raise AASM::InvalidTransition, "Event '#{event.name}' cannot transition from '#{self.aasm_current_state}'"
+        else
+          false
+        end
       end
     rescue StandardError => e
       event.execute_error_callback(self, e)

lib/aasm/base.rb

@@ -4,6 +4,11 @@ def initialize(clazz, options={}, &block)
       @clazz = clazz
       sm = AASM::StateMachine[@clazz]
       sm.config.column = options[:column].to_sym if options[:column]
+      if options.key?(:whiny_transitions)
+        sm.config.whiny_transitions = options[:whiny_transitions]
+      else
+        sm.config.whiny_transitions = true # this is the default, so let's cry
+      end
     end
 
     def state(name, options={})

spec/models/silencer.rb

@@ -0,0 +1,17 @@
+class Silencer
+  include AASM
+
+  aasm :whiny_transitions => false do
+    state :silent, :initial => true
+    state :crying
+    state :smiling
+
+    event :cry do
+      transitions :from => :silent, :to => :crying
+    end
+    event :smile do
+      transitions :from => :crying, :to => :smiling
+    end
+  end
+
+end

spec/unit/state_transition_spec.rb

@@ -1,5 +1,21 @@
 require File.expand_path(File.join(File.dirname(__FILE__), '..', 'spec_helper'))
 
+describe 'transitions' do
+
+  it 'should raise an exception when whiny' do
+    process = ProcessWithNewDsl.new
+    lambda { process.stop! }.should raise_error(AASM::InvalidTransition)
+    process.should be_sleeping
+  end
+
+  it 'should not raise an exception when whiny' do
+    silencer = Silencer.new
+    silencer.smile!.should be_false
+    silencer.should be_silent
+  end
+
+end
+
 describe AASM::SupportingClasses::StateTransition do
   it 'should set from, to, and opts attr readers' do
     opts = {:from => 'foo', :to => 'bar', :guard => 'g'}
@@ -116,9 +132,9 @@
 
     obj.should_receive(:test)
 
-    st.execute(obj, args)    
+    st.execute(obj, args)
   end
-  
+
   it 'should accept a Symbol for the method name' do
     opts = {:from => 'foo', :to => 'bar', :on_transition => :test}
     st = AASM::SupportingClasses::StateTransition.new(opts)
@@ -127,9 +143,9 @@
 
     obj.should_receive(:test)
 
-    st.execute(obj, args)    
+    st.execute(obj, args)
   end
-  
+
   it 'should pass args if the target method accepts them' do
     opts = {:from => 'foo', :to => 'bar', :on_transition => :test}
     st = AASM::SupportingClasses::StateTransition.new(opts)
@@ -144,7 +160,7 @@
 
     return_value.should == 'success'
   end
-  
+
   it 'should NOT pass args if the target method does NOT accept them' do
     opts = {:from => 'foo', :to => 'bar', :on_transition => :test}
     st = AASM::SupportingClasses::StateTransition.new(opts)
@@ -159,5 +175,5 @@
 
     return_value.should == 'success'
   end
-    
+
 end