Rails: How to use before_save to change a field value based on another field?

Question

I\'m trying to set a boolean field to false based on the value of another boolean field. I tried the following with an ActiveRecord model:

  before_save :reconc         


        

Answer 1

before_save is only called after validation has passed. What you need to do is move reconcile_xvent up to before_validation rather than before_save

If you keep that method in before_save what will happen is that it thinks that xvent_hood is null, if you have a validation that checks for nullity of xvent_hood it will fail before the before_save gets called. Which probably explains why you got RecordNotSaved error.

Another thing to keep in mind is that if you have a boolean property, you also can't use validate_presence_of. See http://alexanderwong.me/post/16084280769/rails-validate-presence-of-boolean-and-arrays-mongoid