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| -rw-r--r-- | railties/guides/source/association_basics.textile | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/railties/guides/source/association_basics.textile b/railties/guides/source/association_basics.textile index 03e22bd6fe..4d75fb6dc4 100644 --- a/railties/guides/source/association_basics.textile +++ b/railties/guides/source/association_basics.textile @@ -600,6 +600,7 @@ The +belongs_to+ association supports these options: * +:polymorphic+ * +:readonly+ * +:select+ +* +:touch+ * +:validate+ h6. +:autosave+ @@ -736,6 +737,28 @@ The +:select+ option lets you override the SQL +SELECT+ clause that is used to r TIP: If you set the +:select+ option on a +belongs_to+ association, you should also set the +foreign_key+ option to guarantee the correct results. +h6. +:touch+ + +If you set the +:touch+ option to +:true+, then the +updated_at+ or +updated_on+ timestamp on the associated object will be set to the current time whenever this object is saved or destroyed: + +<ruby> +class Order < ActiveRecord::Base + belongs_to :customer, :touch => true +end + +class Customer < ActiveRecord::Base + has_many :orders +end +</ruby> + +In this case, saving or destroying an order will update the timestamp on the associated customer. You can also specify a particular timestamp attribute to update: + +<ruby> +class Order < ActiveRecord::Base + belongs_to :customer, :touch => :orders_updated_at +end +</ruby> + h6. +:validate+ If you set the +:validate+ option to +true+, then associated objects will be validated whenever you save this object. By default, this is +false+: associated objects will not be validated when this object is saved. @@ -1775,6 +1798,7 @@ h3. Changelog "Lighthouse ticket":http://rails.lighthouseapp.com/projects/16213-rails-guides/tickets/11 +* April 19, 2009: Added +:touch+ option to +belongs_to+ associations by "Mike Gunderloy":credits.html#mgunderloy * February 1, 2009: Added +:autosave+ option "Mike Gunderloy":credits.html#mgunderloy * September 28, 2008: Corrected +has_many :through+ diagram, added polymorphic diagram, some reorganization by "Mike Gunderloy":credits.html#mgunderloy . First release version. * September 22, 2008: Added diagrams, misc. cleanup by "Mike Gunderloy":credits.html#mgunderloy (not yet approved for publication) |