Add convenience predicate methods on Column class. In partial fullfilment of #1236.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2482 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Add convenience predicate methods on Column class. In partial fullfilment of #1236. [skaes@web.de]
+
 * Raise errors when invalid hash keys are passed to ActiveRecord::Base.find. #2363  [Chad Fowler <chad@chadfowler.com>, Nicholas Seckar]
 
 * Added :force option to create_table that'll try to drop the table if it already exists before creating

activerecord/lib/active_record/base.rb

@@ -551,14 +551,19 @@ def table_name
       # Defines the primary key field -- can be overridden in subclasses. Overwriting will negate any effect of the
       # primary_key_prefix_type setting, though.
       def primary_key
+        reset_primary_key
+      end
+
+      def reset_primary_key
+        key = 'id'
         case primary_key_prefix_type
           when :table_name
-            Inflector.foreign_key(class_name_of_active_record_descendant(self), false)
+            key = Inflector.foreign_key(class_name_of_active_record_descendant(self), false)
           when :table_name_with_underscore
-            Inflector.foreign_key(class_name_of_active_record_descendant(self))
-          else
-            "id"
+            key = Inflector.foreign_key(class_name_of_active_record_descendant(self))
         end
+        set_primary_key(key)
+        key
       end
 
       # Defines the column name for use with single table inheritance -- can be overridden in subclasses.
@@ -643,7 +648,11 @@ def class_name(table_name = table_name) # :nodoc:
 
       # Returns an array of column objects for the table associated with this class.
       def columns
-        @columns ||= connection.columns(table_name, "#{name} Columns")
+        unless @columns
+          @columns = connection.columns(table_name, "#{name} Columns")
+          @columns.each {|column| column.primary = column.name == primary_key}
+        end
+        @columns
       end
 
       # Returns an array of column objects for the table associated with this class.
@@ -658,7 +667,7 @@ def column_names
       # Returns an array of columns objects where the primary id, all columns ending in "_id" or "_count",
       # and columns used for single table inheritance has been removed.
       def content_columns
-        @content_columns ||= columns.reject { |c| c.name == primary_key || c.name =~ /(_id|_count)$/ || c.name == inheritance_column }
+        @content_columns ||= columns.reject { |c| c.primary || c.name =~ /(_id|_count)$/ || c.name == inheritance_column }
       end
 
       # Returns a hash of all the methods added to query each of the columns in the table with the name of the method as the key
@@ -1372,7 +1381,7 @@ def attributes_protected_by_default
       def attributes_with_quotes(include_primary_key = true)
         attributes.inject({}) do |quoted, (name, value)|
           if column = column_for_attribute(name)
-            quoted[name] = quote(value, column) unless !include_primary_key && name == self.class.primary_key
+            quoted[name] = quote(value, column) unless !include_primary_key && column.primary
           end
           quoted
         end

activerecord/lib/active_record/connection_adapters/abstract/schema_definitions.rb

@@ -5,6 +5,7 @@ module ConnectionAdapters #:nodoc:
     # An abstract definition of a column in a table.
     class Column
       attr_reader :name, :default, :type, :limit, :null
+      attr_accessor :primary
 
       # Instantiates a new column in the table.
       #
@@ -16,7 +17,18 @@ def initialize(name, default, sql_type = nil, null = true)
         @name, @type, @null = name, simplified_type(sql_type), null
         # have to do this one separately because type_cast depends on #type
         @default = type_cast(default)
-        @limit = extract_limit(sql_type) unless sql_type.nil?
+        @limit   = extract_limit(sql_type) unless sql_type.nil?
+        @primary = nil
+        @text    = [:string, :text].include? @type
+        @number  = [:float, :integer].include? @type
+      end
+
+      def text?
+        @text
+      end
+
+      def number?
+        @number
       end
 
       # Returns the Ruby class that corresponds to the abstract data type.

activerecord/test/pk_test.rb

@@ -44,12 +44,15 @@ def test_find_with_more_than_one_string_key
   
   def test_primary_key_prefix
     ActiveRecord::Base.primary_key_prefix_type = :table_name
+    Topic.reset_primary_key
     assert_equal "topicid", Topic.primary_key
 
     ActiveRecord::Base.primary_key_prefix_type = :table_name_with_underscore
+    Topic.reset_primary_key
     assert_equal "topic_id", Topic.primary_key
 
     ActiveRecord::Base.primary_key_prefix_type = nil
+    Topic.reset_primary_key
     assert_equal "id", Topic.primary_key
   end
 end