Rails how to update a column after saving?

Question

I want to create an after_save method for my rate action. It would divide rating_score/ratings and update the column rating.

class KonkurrancersController &         


        

Answer 1

Not sure why people are upvoting the wrong answer and downvoting the correct answer.

Zakelfassi is right and Christian Fazzini is wrong for Rails 3 and above. If you do #update_attributes in a save callback you go into an endless recursion. You want to do #update_column as per his example.

Try it for yourself and you'll see.

Answer 2

Any update_attribute in an after_save callback will cause recursion, in Rails3+. What should be done is:

after_save :updater
# Awesome Ruby code
# ...
# ...

private

  def updater
    self.update_column(:column_name, new_value) # This will skip validation gracefully.
  end

Answer 3

see this after_save method

Answer 4

  @konkurrancer.update_attributes :ratings=>'updated value'

Answer 5

what you want is a callback. You can create an after_save callback on your Konkurrancer model, which triggers after the save() method is called for that model.

For example:

class Konkurrancer < ActiveRecord::Base
  after_save :do_foobar

  private
    def do_foobar

      rating_score = self.rating_score
      ratings = self.ratings
      rating = (rating_score/ratings)
      self.update_attributes(:ratings => rating)

    end
end

[EDIT] You should use self, since the model you are editing is the model itself. Test it out, and apply necessary logic/implementation.

Have a look at this guide for more info.

Hope that helps!