CODEWITHSUNDEEP
ruby-on-rails
Anas Arshad
Anas Arshad

Reputation: 35

Is there a way to get last updates of associated models?

I have Car model, which is associated with many other models. How can I check updated_at of all associated models and get the latest of them, something like:

Car door was updated at "this time"

I have many associations in my model so getting each one of them and comparing is not efficient. If there is a better way please tell me. Thanks.

Upvotes: 0

Views: 514

Answers (1)

Anuj Khandelwal
Anuj Khandelwal

Reputation: 1244

You could use the touch method here. Basically, touch is used to update the updated_at field of a record. For example, Car.last.touch would set the updated_at field of the last Car record to the current time.
However, touch can also be used with relations, to trigger the touch method on the associated object. So, in your case something like this may work:

class Car < ActiveRecord::Base
  belongs_to :corporation, touch: true
end

class Door < ActiveRecord::Base
  belongs_to :car, touch: true
end

# Door updation triggers updated_at of parent as well
@door = Door.last
@door.updated_at = DateTime.now
@door.save! # Updates updated_at of corresponding car record as well

In the example above, @door.touch could also have been used to update the updated_at of the corresponding parent Car record.

Upvotes: 2

Related Questions