[MODEL] Added support for inherited index names and doc types

This patch adds support for inheriting index_name and document_type on an opt-in basis:

    Elasticsearch::Model.inheritance_enabled = true

    class Animal < ActiveRecord::Base
      document_type 'mammal'
      index_name 'mammals'
    end

    class Dog < Animal
    end

    Animal.document_type   # 'mammal'
    Animal.index_name      # 'mammals'
    Dog.document_type      # 'mammal'
    Dog.index_name         # 'mammals'

Closes #332

Related: #28, #92, #170, #344

elasticsearch-model/lib/elasticsearch/model.rb

@@ -131,7 +131,6 @@ class << self
     end
 
     module ClassMethods
-
       # Get the client common for all models
       #
       # @example Get the client
@@ -181,6 +180,24 @@ def search(query_or_payload, models=[], options={})
         request = Searching::SearchRequest.new(models, query_or_payload, options)
         Response::Response.new(models, request)
       end
+
+      # Check if inheritance is enabled
+      #
+      # @note Inheritance is disabled by default.
+      #
+      def inheritance_enabled
+        @inheritance_enabled ||= false
+      end
+
+      # Enable inheritance of index_name and document_type
+      #
+      # @example Enable inheritance
+      #
+      #     Elasticsearch::Model.inheritance_enabled = true
+      #
+      def inheritance_enabled=(inheritance_enabled)
+        @inheritance_enabled = inheritance_enabled
+      end
     end
     extend ClassMethods
 

elasticsearch-model/lib/elasticsearch/model/naming.rb

@@ -34,7 +34,7 @@ def index_name name=nil, &block
           if @index_name.respond_to?(:call)
             @index_name.call
           else
-            @index_name || self.model_name.collection.gsub(/\//, '-')
+            @index_name || implicit(:index_name)
           end
         end
 
@@ -58,7 +58,7 @@ def index_name=(name)
         #     Article.document_type "my-article"
         #
         def document_type name=nil
-          @document_type = name || @document_type || self.model_name.element
+          @document_type = name || @document_type || implicit(:document_type)
         end
 
 
@@ -69,6 +69,30 @@ def document_type name=nil
         def document_type=(name)
           @document_type = name
         end
+
+        private
+
+          def implicit(prop)
+            value = nil
+
+            if Elasticsearch::Model.inheritance_enabled
+              self.ancestors.each do |klass|
+                next if klass == self
+                break if value = klass.respond_to?(prop) && klass.send(prop)
+              end
+            end
+
+            value || self.send("default_#{prop}")
+          end
+
+          def default_index_name
+            self.model_name.collection.gsub(/\//, '-')
+          end
+
+          def default_document_type
+            self.model_name.element
+          end
+
       end
 
       module InstanceMethods

elasticsearch-model/test/unit/naming_inheritance_test.rb

@@ -0,0 +1,78 @@
+require "test_helper"
+
+class Elasticsearch::Model::NamingInheritanceTest < Test::Unit::TestCase
+  def setup
+    Elasticsearch::Model.inheritance_enabled = true
+  end
+
+  def teardown
+    Elasticsearch::Model.inheritance_enabled = false
+  end
+
+  context "Naming module with inheritance" do
+    class ::TestBase
+      extend ActiveModel::Naming
+
+      extend  Elasticsearch::Model::Naming::ClassMethods
+      include Elasticsearch::Model::Naming::InstanceMethods
+    end
+
+    class ::Animal < ::TestBase
+      extend ActiveModel::Naming
+
+      extend  Elasticsearch::Model::Naming::ClassMethods
+      include Elasticsearch::Model::Naming::InstanceMethods
+
+      index_name "mammals"
+      document_type "mammal"
+    end
+
+    class ::Dog < ::Animal
+    end
+
+    module ::MyNamespace
+      class Dog < ::Animal
+      end
+    end
+
+    should "return the default index_name" do
+      assert_equal "test_bases", TestBase.index_name
+      assert_equal "test_bases", TestBase.new.index_name
+    end
+
+    should "return the explicit index_name" do
+      assert_equal "mammals", Animal.index_name
+      assert_equal "mammals", Animal.new.index_name
+    end
+
+    should "return the ancestor index_name" do
+      assert_equal "mammals", Dog.index_name
+      assert_equal "mammals", Dog.new.index_name
+    end
+
+    should "return the ancestor index_name for namespaced model" do
+      assert_equal "mammals", ::MyNamespace::Dog.index_name
+      assert_equal "mammals", ::MyNamespace::Dog.new.index_name
+    end
+
+    should "return the default document_type" do
+      assert_equal "test_base", TestBase.document_type
+      assert_equal "test_base", TestBase.new.document_type
+    end
+
+    should "return the explicit document_type" do
+      assert_equal "mammal", Animal.document_type
+      assert_equal "mammal", Animal.new.document_type
+    end
+
+    should "return the ancestor document_type" do
+      assert_equal "mammal", Dog.document_type
+      assert_equal "mammal", Dog.new.document_type
+    end
+
+    should "return the ancestor document_type for namespaced model" do
+      assert_equal "mammal", ::MyNamespace::Dog.document_type
+      assert_equal "mammal", ::MyNamespace::Dog.new.document_type
+    end
+  end
+end