Added scope option to validation_uniqueness #349 [Kent Sibilev]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@259 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 28 insertions, 2 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index c85ea7b8bf..6b02d886fe 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Added scope option to validation_uniqueness #349 [Kent Sibilev]
+
 * Added allow_nil options to validates_inclusion_of so that validation is only triggered if the attribute is not nil [what-a-day]
 
 * Added work-around for PostgreSQL and the problem of getting fixtures to be created from id 1 on each test case.
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index 1a4d6c190f..1d0dd68df8 100755
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -198,7 +198,7 @@ module ActiveRecord
       # can be named "davidhh".
       #
       #   class Person < ActiveRecord::Base
-      #     validates_uniqueness_of :user_name
+      #     validates_uniqueness_of :user_name, :scope => "account_id"
       #   end
       #
       # When the record is created, a check is performed to make sure that no record exist in the database with the given value for the specified
@@ -206,12 +206,17 @@ module ActiveRecord
       #
       # Configuration options:
       # * <tt>message</tt> - Specifies a custom error message (default is: "has already been taken")
+      # * <tt>scope</tt> - Ensures that the uniqueness is restricted to a condition of "scope = record.scope"
       def validates_uniqueness_of(*attr_names)
         configuration = { :message => ActiveRecord::Errors.default_error_messages[:taken] }
         configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)
 
         for attr_name in attr_names
-          class_eval(%(validate %{errors.add("#{attr_name}", "#{configuration[:message]}") if self.class.find_first(new_record? ? ["#{attr_name} = ?", #{attr_name}] : ["#{attr_name} = ? AND id <> ?", #{attr_name}, id])}))
+          if scope = configuration[:scope]
+            class_eval(%(validate %{errors.add('#{attr_name}', '#{configuration[:message]}') if self.class.find_first(new_record? ? ['#{attr_name} = ? AND #{scope} = ?', #{attr_name}, #{scope}] : ["#{attr_name} = ? AND id <> ? AND #{scope} = ?", #{attr_name}, id, #{scope}])}))
+          else
+            class_eval(%(validate %{errors.add('#{attr_name}', '#{configuration[:message]}') if self.class.find_first(new_record? ? ['#{attr_name} = ?', #{attr_name}] : ["#{attr_name} = ? AND id <> ?", #{attr_name}, id])}))
+          end
         end
       end
       
diff --git a/activerecord/test/validations_test.rb b/activerecord/test/validations_test.rb
index f5735de59d..db6aab653b 100755
--- a/activerecord/test/validations_test.rb
+++ b/activerecord/test/validations_test.rb
@@ -204,6 +204,25 @@ class ValidationsTest < Test::Unit::TestCase
     assert t2.save, "Should now save t2 as unique"
   end
 
+  def test_validate_uniqueness_with_scope
+    Reply.validates_uniqueness_of(:content, :scope => "parent_id")
+    
+    t = Topic.create("title" => "I'm unique!")
+
+    r1 = t.replies.create "title" => "r1", "content" => "hello world"
+    assert r1.valid?, "Saving r1"
+
+    r2 = t.replies.create "title" => "r2", "content" => "hello world"
+    assert !r2.valid?, "Saving r2 first time"
+
+    r2.content = "something else"
+    assert r2.save, "Saving r2 second time"
+
+    t2 = Topic.create("title" => "I'm unique too!")
+    r3 = t2.replies.create "title" => "r3", "content" => "hello world"
+    assert r3.valid?, "Saving r3"
+  end
+
   def test_validate_format
     Topic.validates_format_of(:title, :content, :with => /^Validation macros rule!$/, :message => "is bad data")