enums

demo_functionality.rb

@@ -41,6 +41,7 @@ ActiveRecord::Schema.define do
                    to_table: :users_fa_aux,
                    primary_key: :base_table_id
                  }
+    t.integer :category
     t.integer :fa_id, index: true
     t.string :title
     t.string :species
@@ -99,6 +100,7 @@ class FaPost < Post
   belongs_to :creator, class_name: "FaUser", inverse_of: :created_posts
   validates :fa_id, presence: true, uniqueness: true
   validates :title, presence: true
+  enum :category, { image: 0, video: 1, text: 2 }
 end
 
 class E621Post < Post

lib/has_aux_table.rb

@@ -57,6 +57,7 @@ module HasAuxTable
       setup_attributes_hook!(config)
       setup_relation_extensions!(config)
       setup_attribute_getter_setter_hooks!(config)
+      setup_enum_hook!(config)
 
       config
     end
@@ -198,9 +199,8 @@ module HasAuxTable
     sig { params(load_schema_method: Method, config: AuxTableConfig).void }
     def aux_config_load_schema!(load_schema_method, config)
       # first, load the main and aux table schemas like normal
-      result = load_schema_method.call
       config.load_aux_schema
-
+      result = load_schema_method.call
       aux_table_name = config.aux_table_name
 
       check_for_overlapping_columns!(
@@ -356,6 +356,49 @@ module HasAuxTable
                        "Auxiliary table columns must not overlap with main table columns."
       end
     end
+
+    sig { params(config: AuxTableConfig).void }
+    def setup_enum_hook!(config)
+      self.define_singleton_method(
+        :enum
+      ) do |name = nil, values = nil, **options, &block|
+        name = name.to_s
+        config.aux.klass.enum(name, values, **options, &block)
+        self.defined_enums.merge!(config.aux.klass.defined_enums)
+
+        # define methods on the main class that delegate to the aux class
+        config
+          .aux
+          .klass
+          .send(:_enum_methods_module)
+          .instance_methods
+          .each do |method_name|
+            self
+              ._enum_methods_module
+              .define_method(method_name) do |*args, **kwargs, &block|
+                raise "not implemented"
+              end
+          end
+
+        define_singleton_method(name.pluralize) do
+          config.aux.klass.send(name.pluralize)
+        end
+
+        values.keys.each do |value_name|
+          value_name = [options[:prefix], value_name, options[:suffix]].reject(
+            &:blank?
+          ).join("_")
+          [
+            value_name,
+            "#{value_name}?",
+            "#{value_name}!",
+            "#{value_name}="
+          ].each do |method_name|
+            config.define_aux_attribute_delegate(method_name.to_sym)
+          end
+        end
+      end
+    end
   end
   mixes_in_class_methods(ClassMethods)
 end

lib/has_aux_table/aux_table_config.rb

@@ -121,7 +121,7 @@ module HasAuxTable
     const :foreign_key, KeyType
     const :primary_key, KeyType
 
-    sig { void }
+    sig { returns(T.untyped) }
     def load_aux_schema
       aux_class.load_schema
     end

spec/active_record/has_aux_table_spec.rb

@@ -111,6 +111,31 @@ RSpec.describe HasAuxTable do
     expect(driver.car).to eq(car)
   end
 
+  it "defined_enums returns the correct values" do
+    engine_types = {
+      "turbofan" => 0,
+      "turboprop" => 1,
+      "piston" => 2,
+      "electric" => 3
+    }
+    expect(Plane.defined_enums).to eq({ "engine_type" => engine_types })
+    expect(Plane.engine_types).to eq(engine_types)
+  end
+
+  it "works with enums" do
+    plane = Plane.create!(name: "Boeing 747", engine_type: :turbofan)
+    expect(plane.engine_type).to eq("turbofan")
+
+    plane.engine_type = "piston"
+    expect(plane.engine_type).to eq("piston")
+    plane.save!
+    expect(plane.engine_type).to eq("piston")
+    expect(plane.piston?).to be_truthy
+
+    plane.turboprop!
+    expect(plane.engine_type).to eq("turboprop")
+  end
+
   describe "#changed?" do
     it "returns true if the main record changes" do
       car = Car.create!(name: "Honda Civic")

spec/spec_helper.rb

@@ -81,6 +81,10 @@ module SpecHelper
         t.create_aux :boat do |t|
           t.boolean :only_freshwater
         end
+
+        t.create_aux :plane do |t|
+          t.integer :engine_type
+        end
       end
 
       create_base_table :people do |t|

spec/spec_models.rb

@@ -21,6 +21,11 @@ class Boat < Vehicle
   belongs_to :captain, inverse_of: :boat
 end
 
+class Plane < Vehicle
+  aux_table :plane
+  enum :engine_type, { turbofan: 0, turboprop: 1, piston: 2, electric: 3 }
+end
+
 class Person < ActiveRecord::Base
   include HasAuxTable
   self.table_name = "people"