Activerecord: use attributes methods instead of attrs var

rubyonrails-talk
1

This is the case: when you call save() on an activerecord::base object it goes through all the attrs[:] and saves them. But I have a lot of attributes overriden. For example:

class Tester   def name     write_attribute(:name, 'This is just a silly example!')     read_attribute(:name)   end end

t = Tester.new t.save

But when I do save() it doesn't get saved to the database if I haven't called the name() method.

When I add a validation, the method somewhere gets called and it is added to the attrs instance variable.

Is there a way, without adding validations for every attribute, to call the attribute methods before save?

I thought about using a before_save filter, but maybe someone would new a better/other way.

I'm just curious if it's possible. Maybe I'm on the wrong track and there may be better ways to override the attribute getters?

Thanks in advance!

2

You’re essentially trying to set default values for your attributes, right? If so, I would use the #after_initialize callback, which AR calls when a new instance of the class is created.

class Tester < ActiveRecord::Base def after_initialize self.name ||= ‘Default name’ end

end

Brandon

3

I would recommend the before_create callback. it seems you do not need to overwrite the the attributes everytime you update it, and before_create work only for new records.

after_initialize has performance issue and overwrite the default getter may cause side effects.

hope that helps.

Regards,

Peng Zuo