Rails model before_save with MD5 digest

Question

I have a model that some record must be filled automatically after the user input.

Then I used before_save callback, but the records will not be stored.

This is my model:

before_save :create_relation_plus_md5
has_many :bridges
attr_accessible :id, :admin_user_id, :md5, :url, :name, :cBox

validates_presence_of :name
validates_uniqueness_of :name



def create_relation_plus_md5
    baseUrl = "http://www.mysite.com/?id="
    digest = Digest::MD5.hexdigest("#{name}#{id}#{someOtherData}")
    puts "digest : #{digest}"
    md5 = digest
    url = "#{baseUrl}#{digest}"
    # + create relations
end

The md5 and url will not be stored, I think I miss something. Maybe I must call the save explicitly in the method?

I can do with a workaround with after_save and call back the model manually, but naturally this create a infinite loop...

Answer 1

You need to reference self explicitly if you want to call a setter method. Otherwise you will assign to a local variable

md5 = "foo" # local variable
self.md5 = "foo" # method call, value will be stored in the instance.