Fixes issue #273 - translations for namespaced models.

ActiveRecord uses i18n_key methods which return
"namespace/model_name"("namespace.model_name" in rails 3.0.x) for
Namespace::ModelName. Ransack should used the same pattern.

Adapted from original commit by github.com/Bonias

lib/ransack/translate.rb

@@ -26,7 +26,7 @@ module Ransack
       attribute_names = attributes_str.split(/_and_|_or_/)
       combinator = attributes_str.match(/_and_/) ? :and : :or
       defaults = base_ancestors.map do |klass|
-        :"ransack.attributes.#{klass.model_name.singular}.#{original_name}"
+        :"ransack.attributes.#{i18n_key(klass)}.#{original_name}"
       end
 
       translated_names = attribute_names.map do |attr|
@@ -54,12 +54,11 @@ module Ransack
         raise ArgumentError, "A context is required to translate associations"
       end
 
-      defaults = key.blank? ? [:"#{context.klass.i18n_scope}.models.#{
-        context.klass.model_name.singular}"] : [
-        :"ransack.associations.#{context.klass.model_name.singular
-        }.#{key}"]
+      defaults = key.blank? ?
+        [:"#{context.klass.i18n_scope}.models.#{i18n_key(context.klass)}"] :
+        [:"ransack.associations.#{i18n_key(context.klass)}.#{key}"]
       defaults << context.traverse(key).model_name.human
-      options = {count: 1, default: defaults}
+      options = { count: 1, default: defaults }
       I18n.translate(defaults.shift, options)
     end
 
@@ -71,22 +70,19 @@ module Ransack
       attr_name = name.sub(/^#{assoc_path}_/, '')
       interpolations = {}
       interpolations[:attr_fallback_name] = I18n.translate(
-        (associated_class ? 
-          :"ransack.attributes.#{associated_class.model_name.singular}.#{attr_name}" : 
-          :"ransack.attributes.#{context.klass.model_name.singular}.#{attr_name}"
-        ),
+        :"ransack.attributes.#{
+          i18n_key(associated_class || context.klass)
+          }.#{attr_name}",
         default: [
           (associated_class ? 
-            :"#{associated_class.i18n_scope}.attributes.#{associated_class.model_name.singular}.#{attr_name}" : 
-            :"#{context.klass.i18n_scope}.attributes.#{context.klass.model_name.singular}.#{attr_name}"
+          :"#{associated_class.i18n_scope}.attributes.#{i18n_key(associated_class)}.#{attr_name}" :
+          :"#{context.klass.i18n_scope}.attributes.#{i18n_key(context.klass)}.#{attr_name}"
           ),
           :".attributes.#{attr_name}",
           attr_name.humanize
         ]
       )
-      defaults = [
-        :"ransack.attributes.#{context.klass.model_name.singular}.#{name}"
-      ]
+      defaults = [:"ransack.attributes.#{i18n_key(context.klass)}.#{name}"]
       if include_associations && associated_class
         defaults << '%{association_name} %{attr_fallback_name}'
         interpolations[:association_name] = association(
@@ -96,8 +92,12 @@ module Ransack
       else
         defaults << '%{attr_fallback_name}'
       end
-      options = {count: 1, default: defaults}
+      options = { count: 1, default: defaults }
       I18n.translate(defaults.shift, options.merge(interpolations))
     end
+
+    def self.i18n_key(klass)
+      klass.model_name.i18n_key
+    end
   end
 end

spec/ransack/translate_spec.rb

@@ -0,0 +1,16 @@
+require 'spec_helper'
+
+module Ransack
+  describe Translate do
+
+    describe '.attribute' do
+      it 'translate namespaced attribute like AR does' do
+        ar_translation = ::Namespace::Article.human_attribute_name(:title)
+        ransack_translation = Ransack::Translate.attribute(
+          :title, :context => ::Namespace::Article.search.context
+          )
+        ransack_translation.should eq ar_translation
+      end
+    end
+  end
+end

spec/support/en.yml

@@ -4,4 +4,10 @@ en:
   ransack:
     attributes:
       person:
-        name: Full Name
+        name: Full Name
+  activerecord:
+    attributes:
+      namespace/article:
+        title: AR Namespaced Title
+      namespace_article:
+        title: Old Ransack Namespaced Title

spec/support/schema.rb

@@ -66,6 +66,12 @@ class Article < ActiveRecord::Base
   has_many                :notes, as: :notable
 end
 
+module Namespace
+  class Article < ::Article
+
+  end
+end
+
 class Comment < ActiveRecord::Base
   belongs_to :article
   belongs_to :person