1 files changed, 71 insertions, 5 deletions
diff --git a/railties/lib/rails/generators/generated_attribute.rb b/railties/lib/rails/generators/generated_attribute.rb
index 816d82cac3..25d0161e4c 100644
--- a/railties/lib/rails/generators/generated_attribute.rb
+++ b/railties/lib/rails/generators/generated_attribute.rb
@@ -1,14 +1,60 @@
 require 'active_support/time'
-require 'active_support/core_ext/object/inclusion'
 
 module Rails
   module Generators
     class GeneratedAttribute
+      INDEX_OPTIONS = %w(index uniq)
+      UNIQ_INDEX_OPTIONS = %w(uniq)
+
       attr_accessor :name, :type
+      attr_reader   :attr_options
+
+      class << self
+        def parse(column_definition)
+          name, type, has_index = column_definition.split(':')
+
+          # if user provided "name:index" instead of "name:string:index"
+          # type should be set blank so GeneratedAttribute's constructor
+          # could set it to :string
+          has_index, type = type, nil if INDEX_OPTIONS.include?(type)
+
+          type, attr_options = *parse_type_and_options(type)
+          type = type.to_sym if type
+
+          if type && reference?(type)
+            references_index = UNIQ_INDEX_OPTIONS.include?(has_index) ? { :unique => true } : true
+            attr_options[:index] = references_index
+          end
+
+          new(name, type, has_index, attr_options)
+        end
+
+        def reference?(type)
+          [:references, :belongs_to].include? type
+        end
+
+        private
+
+        # parse possible attribute options like :limit for string/text/binary/integer or :precision/:scale for decimals
+        # when declaring options curly brackets should be used
+        def parse_type_and_options(type)
+          case type
+          when /(string|text|binary|integer)\{(\d+)\}/
+            return $1, :limit => $2.to_i
+          when /decimal\{(\d+)[,.-](\d+)\}/
+            return :decimal, :precision => $1.to_i, :scale => $2.to_i
+          else
+            return type, {}
+          end
+        end
+      end
 
-      def initialize(name, type)
-        type = :string if type.blank?
-        @name, @type = name, type.to_sym
+      def initialize(name, type=nil, index_type=false, attr_options={})
+        @name           = name
+        @type           = type || :string
+        @has_index      = INDEX_OPTIONS.include?(index_type)
+        @has_uniq_index = UNIQ_INDEX_OPTIONS.include?(index_type)
+        @attr_options   = attr_options
       end
 
       def field_type
@@ -45,8 +91,28 @@ module Rails
         name.to_s.humanize
       end
 
+      def index_name
+        reference? ? "#{name}_id" : name
+      end
+
       def reference?
-        self.type.in?([:references, :belongs_to])
+        self.class.reference?(type)
+      end
+
+      def has_index?
+        @has_index
+      end
+
+      def has_uniq_index?
+        @has_uniq_index
+      end
+
+      def inject_options
+        "".tap { |s| @attr_options.each { |k,v| s << ", #{k}: #{v.inspect}" } }
+      end
+
+      def inject_index_options
+        has_uniq_index? ? ", unique: true" : ""
       end
     end
   end