Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
Browse files

Modified comments explaining what the update_only option does.

  • Loading branch information...
commit 27da612eeca83de3fd775b5460113f7b4eb12fad 1 parent acf7e86
Mark authored
Showing with 19 additions and 8 deletions.
  1. +19 −8 activerecord/lib/active_record/nested_attributes.rb
27 activerecord/lib/active_record/nested_attributes.rb
View
@@ -248,10 +248,18 @@ module ClassMethods
# exception is raised. If omitted, any number associations can be processed.
# Note that the :limit option is only applicable to one-to-many associations.
# [:update_only]
- # Allows you to specify that an existing record may only be updated.
- # A new record may only be created when there is no existing record.
- # This option only works for one-to-one associations and is ignored for
- # collection associations. This option is off by default.
+ # For a one-to-one association, this option allows you to specify how
+ # nested attributes are to be used when an associated record already
+ # exists. In general, an existing record may either be updated with the
+ # new set of attribute values or be replaced by a wholly new record
+ # containing those values. By default the :update_only option is +false+
+ # and the nested attributes are used to update the existing record only
+ # if they include the record's <tt>:id</tt> value. Otherwise a new
+ # record will be instantiated and used to replace the existing one.
+ # However if the :update_only option is +true+, the nested attributes
+ # are used to update the record's attributes always, regardless of
+ # whether the <tt>:id</tt> is present. The option is ignored for collection
+ # associations.
#
# Examples:
# # creates avatar_attributes=
@@ -312,10 +320,13 @@ def _destroy
# Assigns the given attributes to the association.
#
- # If update_only is false and the given attributes include an <tt>:id</tt>
- # that matches the existing record's id, then the existing record will be
- # modified. If update_only is true, a new record is only created when no
- # object exists. Otherwise a new record will be built.
+ # If an associated record does not yet exist, one will be instantiated. If
+ # an associated record already exists, the method's behavior depends on
+ # the value of the update_only option. If update_only is +false+ and the
+ # given attributes include an <tt>:id</tt> that matches the existing record's
+ # id, then the existing record will be modified. If no <tt>:id</tt> is provided
+ # it will be replaced with a new record. If update_only is +true+ the existing
+ # record will be modified regardless of whether an <tt>:id</tt> is provided.
#
# If the given attributes include a matching <tt>:id</tt> attribute, or
# update_only is true, and a <tt>:_destroy</tt> key set to a truthy value,
Please sign in to comment.
Something went wrong with that request. Please try again.