Allow namespacing methods and state constants

lib/aasm/base.rb

@@ -29,6 +29,9 @@ module AASM
 
       configure :enum, nil
 
+      # Set to true to namespace reader methods and constants
+      configure :namespace, false
+
       # make sure to raise an error if no_direct_assignment is enabled
       # and attribute is directly assigned though
       @klass.class_eval %Q(
@@ -66,18 +69,30 @@ module AASM
     def state(name, options={})
       @state_machine.add_state(name, @klass, options)
 
-      if @klass.instance_methods.include?("#{name}?")
+      if namespace?
+        method_name = "#{namespace}_#{name}"
+      else
+        method_name = name
+      end
+
+      if @klass.instance_methods.include?("#{method_name}?")
         warn "#{@klass.name}: The state name #{name} is already used!"
       end
 
       @klass.class_eval <<-EORUBY, __FILE__, __LINE__ + 1
-        def #{name}?
+        def #{method_name}?
           aasm(:#{@name}).current_state == :#{name}
         end
       EORUBY
 
-      unless @klass.const_defined?("STATE_#{name.upcase}")
-        @klass.const_set("STATE_#{name.upcase}", name)
+      if namespace?
+        const_name = "STATE_#{namespace.upcase}_#{name.upcase}"
+      else
+        const_name = "STATE_#{name.upcase}"
+      end
+
+      unless @klass.const_defined?(const_name)
+        @klass.const_set(const_name, name)
       end
     end
 
@@ -148,5 +163,16 @@ module AASM
       end
     end
 
+    def namespace?
+      !!@state_machine.config.namespace
+    end
+
+    def namespace
+      if @state_machine.config.namespace == true
+        @name
+      else
+        @state_machine.config.namespace
+      end
+    end
   end
 end

lib/aasm/configuration.rb

@@ -19,5 +19,8 @@ module AASM
     attr_accessor :no_direct_assignment
 
     attr_accessor :enum
+
+    # namespace reader methods and constants
+    attr_accessor :namespace
   end
-end
+end

spec/models/namespaced_multiple_example.rb

@@ -0,0 +1,28 @@
+class NamespacedMultipleExample
+  include AASM
+  aasm(:status) do
+    state :unapproved, :initial => true
+    state :approved
+
+    event :approve do
+      transitions :from => :unapproved, :to => :approved
+    end
+
+    event :unapprove do
+      transitions :from => :approved, :to => :unapproved
+    end
+  end
+
+  aasm(:review_status, namespace: :review) do
+    state :unapproved, :initial => true
+    state :approved
+
+    event :approve_review do
+      transitions :from => :unapproved, :to => :approved
+    end
+
+    event :unapprove_review do
+      transitions :from => :approved, :to => :unapproved
+    end
+  end
+end

spec/unit/namespaced_multiple_example_spec.rb

@@ -0,0 +1,53 @@
+require 'spec_helper'
+
+describe 'state machine' do
+  let(:namespaced) { NamespacedMultipleExample.new }
+
+  it 'starts with an initial state' do
+    expect(namespaced.aasm(:status).current_state).to eq(:unapproved)
+    expect(namespaced).to respond_to(:unapproved?)
+    expect(namespaced).to be_unapproved
+
+    expect(namespaced.aasm(:review_status).current_state).to eq(:unapproved)
+    expect(namespaced).to respond_to(:review_unapproved?)
+    expect(namespaced).to be_review_unapproved
+  end
+
+  it 'allows transitions to other states' do
+    expect(namespaced).to respond_to(:approve)
+    expect(namespaced).to respond_to(:approve!)
+    namespaced.approve!
+    expect(namespaced).to respond_to(:approved?)
+    expect(namespaced).to be_approved
+
+    expect(namespaced).to respond_to(:approve_review)
+    expect(namespaced).to respond_to(:approve_review!)
+    namespaced.approve_review!
+    expect(namespaced).to respond_to(:review_approved?)
+    expect(namespaced).to be_review_approved
+  end
+
+  it 'denies transitions to other states' do
+    expect {namespaced.unapprove}.to raise_error(AASM::InvalidTransition)
+    expect {namespaced.unapprove!}.to raise_error(AASM::InvalidTransition)
+    namespaced.approve
+    expect {namespaced.approve}.to raise_error(AASM::InvalidTransition)
+    expect {namespaced.approve!}.to raise_error(AASM::InvalidTransition)
+    namespaced.unapprove
+
+    expect {namespaced.unapprove_review}.to raise_error(AASM::InvalidTransition)
+    expect {namespaced.unapprove_review!}.to raise_error(AASM::InvalidTransition)
+    namespaced.approve_review
+    expect {namespaced.approve_review}.to raise_error(AASM::InvalidTransition)
+    expect {namespaced.approve_review!}.to raise_error(AASM::InvalidTransition)
+    namespaced.unapprove_review
+  end
+
+  it 'defines constants for each state name' do
+    expect(NamespacedMultipleExample::STATE_UNAPPROVED).to eq(:unapproved)
+    expect(NamespacedMultipleExample::STATE_APPROVED).to eq(:approved)
+
+    expect(NamespacedMultipleExample::STATE_REVIEW_UNAPPROVED).to eq(:unapproved)
+    expect(NamespacedMultipleExample::STATE_REVIEW_APPROVED).to eq(:approved)
+  end
+end