Introduce dynamic scopes for ActiveRecord: you can now use class methods like scoped_by_user_name(user_name) and scoped_by_user_name_and_password(user_name, password) that will use the scoped method with attributes you supply. [#1648 state:committed]

Signed-off-by: David Heinemeier Hansson <david@loudthinking.com>

1 files changed, 24 insertions, 1 deletions

diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index e5e94555eb..5198dbfa9b 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1456,7 +1456,10 @@ module ActiveRecord #:nodoc:
       def respond_to?(method_id, include_private = false)
         if match = DynamicFinderMatch.match(method_id)
           return true if all_attributes_exists?(match.attribute_names)
+        elsif match = DynamicScopeMatch.match(method_id)
+          return true if all_attributes_exists?(match.attribute_names)
         end
+        
         super
       end
 
@@ -1809,7 +1812,11 @@ module ActiveRecord #:nodoc:
         # This also enables you to initialize a record if it is not found, such as find_or_initialize_by_amount(amount)
         # or find_or_create_by_user_and_password(user, password).
         #
-        # Each dynamic finder or initializer/creator is also defined in the class after it is first invoked, so that future
+        # Also enables dynamic scopes like scoped_by_user_name(user_name) and scoped_by_user_name_and_password(user_name, password) that
+        # are turned into scoped(:conditions => ["user_name = ?", user_name]) and scoped(:conditions => ["user_name = ? AND password = ?", user_name, password])
+        # respectively.
+        #
+        # Each dynamic finder, scope or initializer/creator is also defined in the class after it is first invoked, so that future
         # attempts to use it do not run through method_missing.
         def method_missing(method_id, *arguments, &block)
           if match = DynamicFinderMatch.match(method_id)
@@ -1868,6 +1875,22 @@ module ActiveRecord #:nodoc:
               }, __FILE__, __LINE__
               send(method_id, *arguments, &block)
             end
+          elsif match = DynamicScopeMatch.match(method_id)
+            attribute_names = match.attribute_names
+            super unless all_attributes_exists?(attribute_names)
+            if match.scope?
+              self.class_eval %{
+                def self.#{method_id}(*args)                        # def self.scoped_by_user_name_and_password(*args)
+                  options = args.extract_options!                   #   options = args.extract_options!
+                  attributes = construct_attributes_from_arguments( #   attributes = construct_attributes_from_arguments(
+                    [:#{attribute_names.join(',:')}], args          #     [:user_name, :password], args
+                  )                                                 #   )
+                                                                    # 
+                  scoped(:conditions => attributes)                 #   scoped(:conditions => attributes)
+                end                                                 # end
+              }, __FILE__, __LINE__
+              send(method_id, *arguments)
+            end
           else
             super
           end