initial statemachine machine and state classes

5 files changed, 115 insertions, 2 deletions

diff --git a/activemodel/lib/active_model/callbacks.rb b/activemodel/lib/active_model/callbacks.rb
index 1dd20156ec..c94f76109f 100644
--- a/activemodel/lib/active_model/callbacks.rb
+++ b/activemodel/lib/active_model/callbacks.rb
@@ -1,4 +1,4 @@
-require 'active_model/observing'
+require 'active_model/core'
 
 module ActiveModel
   module Callbacks
diff --git a/activemodel/lib/active_model/state_machine.rb b/activemodel/lib/active_model/state_machine.rb
new file mode 100644
index 0000000000..bb038f6b7a
--- /dev/null
+++ b/activemodel/lib/active_model/state_machine.rb
@@ -0,0 +1,43 @@
+Dir[File.dirname(__FILE__) + "/state_machine/*.rb"].sort.each do |path|
+  filename = File.basename(path)
+  require "active_model/state_machine/#{filename}"
+end
+
+module ActiveModel
+  module StateMachine
+    def self.included(base)
+      base.extend ClassMethods
+    end
+
+    module ClassMethods
+      def inherited(klass)
+        super
+        klass.state_machines = state_machines
+      end
+
+      def state_machines
+        @state_machines ||= {}
+      end
+
+      def state_machines=(value)
+        @state_machines = value ? value.dup : nil
+      end
+
+      def state_machine(name = nil, options = {}, &block)
+        if name.is_a?(Hash)
+          options = name
+          name    = nil
+        end
+        name ||= :default
+        state_machines[name] ||= Machine.new(self, name)
+        block ? state_machines[name].update(options, &block) : state_machines[name]
+      end
+    end
+
+    def current_state(name = nil)
+      sm   = self.class.state_machine(name)
+      ivar = "@#{sm.name}_current_state"
+      instance_variable_get(ivar) || instance_variable_set(ivar, sm.initial_state)
+    end
+  end
+end
\ No newline at end of file
diff --git a/activemodel/lib/active_model/state_machine/machine.rb b/activemodel/lib/active_model/state_machine/machine.rb
new file mode 100644
index 0000000000..75ed8f8b65
--- /dev/null
+++ b/activemodel/lib/active_model/state_machine/machine.rb
@@ -0,0 +1,30 @@
+module ActiveModel
+  module StateMachine
+    class Machine
+      attr_accessor :initial_state, :states, :event
+      attr_reader :klass, :name
+
+      def initialize(klass, name)
+        @klass, @name, @states, @events = klass, name, [], {}
+      end
+
+      def states_for_select
+        states.map { |st| [st.display_name, st.name.to_s] }
+      end
+
+      def state(name, options = {})
+        @states << State.new(self, name, options)
+      end
+
+      def initial_state
+        @initial_state ||= (states.first ? states.first.name : nil)
+      end
+
+      def update(options = {}, &block)
+        @initial_state = options[:initial]
+        instance_eval(&block)
+        self
+      end
+    end
+  end
+end
\ No newline at end of file
diff --git a/activemodel/lib/active_model/state_machine/state.rb b/activemodel/lib/active_model/state_machine/state.rb
new file mode 100644
index 0000000000..5851a6fb79
--- /dev/null
+++ b/activemodel/lib/active_model/state_machine/state.rb
@@ -0,0 +1,40 @@
+module ActiveModel
+  module StateMachine
+    class State
+      attr_reader :name, :options
+
+      def initialize(machine, name, options={})
+        @machine, @name, @options, @display_name = machine, name, options, options.delete(:display)
+        machine.klass.send(:define_method, "#{name}?") do
+          current_state.to_s == name.to_s
+        end
+      end
+
+      def ==(state)
+        if state.is_a? Symbol
+          name == state
+        else
+          name == state.name
+        end
+      end
+
+      def call_action(action, record)
+        action = @options[action]
+        case action
+        when Symbol, String
+          record.send(action)
+        when Proc
+          action.call(record)
+        end
+      end
+
+      def display_name
+        @display_name ||= name.to_s.gsub(/_/, ' ').capitalize
+      end
+
+      def for_select
+        [display_name, name.to_s]
+      end
+    end
+  end
+end
diff --git a/activemodel/lib/active_model/validations.rb b/activemodel/lib/active_model/validations.rb
index 6b692e6a9a..7efe9901ca 100644
--- a/activemodel/lib/active_model/validations.rb
+++ b/activemodel/lib/active_model/validations.rb
@@ -1,4 +1,4 @@
-require 'active_model/observing'
+require 'active_model/core'
 
 module ActiveModel
   module Validations