:enum configuration now can be omitted if AASM column points to an

integer column. :enum can be set to true; in this case AASM would infer
enum method name from AASM column name.

README.md

@@ -293,15 +293,23 @@ class Job < ActiveRecord::Base
     running: 99
   }
 
-  aasm :column => :state, :enum => :states do
+  aasm :column => :state, :enum => true do
     state :sleeping, :initial => true
     state :running
   end
 end
 ```
 
-You need to pass the name of the method which provides access to the
-enumeration mapping as a value of ```enum```.
+You can explicitly pass the name of the method which provides access
+to the enumeration mapping as a value of ```enum```, or you can simply
+set it to true. In the latter case AASM will try to use pluralized
+column name to access possible enum states.
+
+Furthermore, if your column has integer type (which is normally the
+case when you ), you can omit ```:enum``` setting - AASM auto-detects
+this situation and enabled enum support. If anything goes wrong, you
+can disable enum functionali and fall back to default behavior by
+setting ```:enum => false```.
 
 ### Sequel
 

lib/aasm/persistence/active_record_persistence.rb

@@ -119,7 +119,20 @@ module AASM
 
       private
         def aasm_enum
-          AASM::StateMachine[self.class].config.enum
+          case AASM::StateMachine[self.class].config.enum
+            when false then nil
+            when true then aasm_guess_enum_method
+            when nil then aasm_guess_enum_method if aasm_column_looks_like_enum
+            else AASM::StateMachine[self.class].config.enum
+          end
+        end
+
+        def aasm_column_looks_like_enum
+          self.class.columns_hash[self.class.aasm_column.to_s].type == :integer
+        end
+
+        def aasm_guess_enum_method
+          self.class.aasm_column.to_s.pluralize.to_sym
         end
 
         def aasm_skipping_validations

spec/unit/persistence/active_record_persistence_spec.rb

@@ -23,6 +23,115 @@ describe "instance methods" do
     expect(gate).to respond_to(:aasm_write_state_without_persistence)
   end
 
+  describe "aasm_column_looks_like_enum" do
+    subject { lambda{ gate.send(:aasm_column_looks_like_enum) } }
+
+    let(:column_name) { "value" }
+    let(:columns_hash) { Hash[column_name, column] }
+
+    before :each do
+      gate.class.stub(:aasm_column).and_return(column_name.to_sym)
+      gate.class.stub(:columns_hash).and_return(columns_hash)
+    end
+
+    context "when AASM column has integer type" do
+      let(:column) { double(Object, type: :integer) }
+
+      it "returns true" do
+        expect(subject.call).to be_true
+      end
+    end
+
+    context "when AASM column has string type" do
+      let(:column) { double(Object, type: :string) }
+
+      it "returns false" do
+        expect(subject.call).to be_false
+      end
+    end
+  end
+
+  describe "aasm_guess_enum_method" do
+    subject { lambda{ gate.send(:aasm_guess_enum_method) } }
+
+    before :each do
+      gate.class.stub(:aasm_column).and_return(:value)
+    end
+
+    it "pluralizes AASM column name" do
+      expect(subject.call).to eq :values
+    end
+  end
+
+  describe "aasm_enum" do
+    subject { lambda{ gate.send(:aasm_enum) } }
+
+    context "when AASM enum setting contains an explicit enum method name" do
+      let(:enum) { :test }
+
+      before :each do
+        AASM::StateMachine[Gate].config.stub(:enum).and_return(enum)
+      end
+
+      it "returns whatever value was set in AASM config" do
+        expect(subject.call).to eq enum
+      end
+    end
+
+    context "when AASM enum setting is simply set to true" do
+      before :each do
+        AASM::StateMachine[Gate].config.stub(:enum).and_return(true)
+        Gate.stub(:aasm_column).and_return(:value)
+        gate.stub(:aasm_guess_enum_method).and_return(:values)
+      end
+
+      it "infers enum method name from pluralized column name" do
+        expect(subject.call).to eq :values
+        expect(gate).to have_received :aasm_guess_enum_method
+      end
+    end
+
+    context "when AASM enum setting is explicitly disabled" do
+      before :each do
+        AASM::StateMachine[Gate].config.stub(:enum).and_return(false)
+      end
+
+      it "returns nil" do
+        expect(subject.call).to be_nil
+      end
+    end
+
+    context "when AASM enum setting is not enabled" do
+      before :each do
+        AASM::StateMachine[Gate].config.stub(:enum).and_return(nil)
+        Gate.stub(:aasm_column).and_return(:value)
+      end
+
+      context "when AASM column looks like enum" do
+        before :each do
+          gate.stub(:aasm_column_looks_like_enum).and_return(true)
+          gate.stub(:aasm_guess_enum_method).and_return(:values)
+        end
+
+        it "infers enum method name from pluralized column name" do
+          expect(subject.call).to eq :values
+          expect(gate).to have_received :aasm_guess_enum_method
+        end
+      end
+
+      context "when AASM column doesn't look like enum'" do
+        before :each do
+          gate.stub(:aasm_column_looks_like_enum)
+            .and_return(false)
+        end
+
+        it "returns nil, as we're not using enum" do
+          expect(subject.call).to be_nil
+        end
+      end
+    end
+  end
+
   context "when AASM is configured to use enum" do
     let(:state_sym) { :running }
     let(:state_code) { 2 }