aboutsummaryrefslogtreecommitdiffstats
path: root/activerecord
diff options
context:
space:
mode:
Diffstat (limited to 'activerecord')
-rw-r--r--activerecord/CHANGELOG2
-rwxr-xr-xactiverecord/lib/active_record/validations.rb12
2 files changed, 14 insertions, 0 deletions
diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 24856fa143..d8b0e2a6ff 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
*SVN*
+* Add warning about the proper way to validate the presence of a foreign key. Closes #4147. [Francois Beausoleil <francois.beausoleil@gmail.com>]
+
* Fix syntax error in documentation. Closes #4679. [mislav@nippur.irb.hr]
* Add Oracle support for CLOB inserts. Closes #4748. [schoenm@earthlink.net sandra.metz@duke.edu]
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index 9e58599f81..d416773464 100755
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -386,6 +386,18 @@ module ActiveRecord
# * <tt>if</tt> - Specifies a method, proc or string to call to determine if the validation should
# occur (e.g. :if => :allow_validation, or :if => Proc.new { |user| user.signup_step > 2 }). The
# method, proc or string should return or evaluate to a true or false value.
+ #
+ # === Warning
+ # Validate the presence of the foreign key, not the instance variable itself.
+ # Do this:
+ # validate_presence_of :invoice_id
+ #
+ # Not this:
+ # validate_presence_of :invoice
+ #
+ # If you validate the presence of the associated object, you will get
+ # failures on saves when both the parent object and the child object are
+ # new.
def validates_presence_of(*attr_names)
configuration = { :message => ActiveRecord::Errors.default_error_messages[:blank], :on => :save }
configuration.update(attr_names.pop) if attr_names.last.is_a?(Hash)