Make has_one with :conditions hash scope build or creation of the associated...

Make has_one with :conditions hash scope build or creation of the associated object with those conditions
Signed-off-by: NMichael Koziarski <michael@koziarski.com>
[#3088 state:committed]

activerecord/lib/active_record/associations.rb

@@ -938,7 +938,9 @@ def has_many(association_id, options = {}, &extension)
       #   if the real class name is Person, you'll have to specify it with this option.
       # [:conditions]
       #   Specify the conditions that the associated object must meet in order to be included as a +WHERE+
-      #   SQL fragment, such as <tt>rank = 5</tt>.
+      #   SQL fragment, such as <tt>rank = 5</tt>. Record creation from the association is scoped if a hash
+      #   is used. <tt>has_one :account, :conditions => {:enabled => true}</tt> will create an enabled account with <tt>@company.create_account</tt>
+      #   or <tt>@company.build_account</tt>.
       # [:order]
       #   Specify the order in which the associated objects are returned as an <tt>ORDER BY</tt> SQL fragment,
       #   such as <tt>last_name, first_name DESC</tt>.

activerecord/lib/active_record/associations/has_one_association.rb

@@ -8,18 +8,21 @@ def initialize(owner, reflection)
 
       def create(attrs = {}, replace_existing = true)
         new_record(replace_existing) do |reflection|
+          attrs = merge_with_conditions(attrs)
           reflection.create_association(attrs)
         end
       end
 
       def create!(attrs = {}, replace_existing = true)
         new_record(replace_existing) do |reflection|
+          attrs = merge_with_conditions(attrs)
           reflection.create_association!(attrs)
         end
       end
 
       def build(attrs = {}, replace_existing = true)
         new_record(replace_existing) do |reflection|
+          attrs = merge_with_conditions(attrs)
           reflection.build_association(attrs)
         end
       end
@@ -128,6 +131,12 @@ def we_can_set_the_inverse_on_this?(record)
           inverse = @reflection.inverse_of
           return !inverse.nil?
         end
+
+        def merge_with_conditions(attrs={})
+          attrs ||= {}
+          attrs.update(@reflection.options[:conditions]) if @reflection.options[:conditions].is_a?(Hash)
+          attrs
+        end
     end
   end
 end

activerecord/test/cases/associations/has_one_associations_test.rb

@@ -315,4 +315,22 @@ def test_save_of_record_with_loaded_has_one
       Firm.find(@firm.id, :include => :account).save!
     end
   end
+
+  def test_build_respects_hash_condition
+    account = companies(:first_firm).build_account_limit_500_with_hash_conditions
+    assert account.save
+    assert_equal 500, account.credit_limit
+  end
+
+  def test_create_respects_hash_condition
+    account = companies(:first_firm).create_account_limit_500_with_hash_conditions
+    assert       !account.new_record?
+    assert_equal 500, account.credit_limit
+  end
+
+  def test_create!_respects_hash_condition
+    account = companies(:first_firm).create_account_limit_500_with_hash_conditions!
+    assert       !account.new_record?
+    assert_equal 500, account.credit_limit
+  end
 end

activerecord/test/cases/reflection_test.rb

@@ -176,9 +176,9 @@ def test_association_reflection_in_modules
 
   def test_reflection_of_all_associations
     # FIXME these assertions bust a lot
-    assert_equal 35, Firm.reflect_on_all_associations.size
+    assert_equal 36, Firm.reflect_on_all_associations.size
     assert_equal 26, Firm.reflect_on_all_associations(:has_many).size
-    assert_equal 9, Firm.reflect_on_all_associations(:has_one).size
+    assert_equal 10, Firm.reflect_on_all_associations(:has_one).size
     assert_equal 0, Firm.reflect_on_all_associations(:belongs_to).size
   end
 

activerecord/test/models/company.rb

@@ -81,6 +81,8 @@ class Firm < Company
   has_one :account_using_foreign_and_primary_keys, :foreign_key => "firm_name", :primary_key => "name", :class_name => "Account"
   has_one :deletable_account, :foreign_key => "firm_id", :class_name => "Account", :dependent => :delete
   
+  has_one :account_limit_500_with_hash_conditions, :foreign_key => "firm_id", :class_name => "Account", :conditions => { :credit_limit => 500 }
+
   has_one :unautosaved_account, :foreign_key => "firm_id", :class_name => 'Account', :autosave => false
   has_many :accounts
   has_many :unautosaved_accounts, :foreign_key => "firm_id", :class_name => 'Account', :autosave => false