Question

I’m new to ruby on rails, and I’ve inherited a codebase. Right now I can’t create a new user account in my application, when I try I get the following error:

NoMethodError in Users::RegistrationsController#create

undefined method `name’ for nil:NilClass
Rails.root: /home/nathan/dev/legwork-core

Application Trace | Framework Trace | Full Trace
app/models/contact.rb:74:in block (2 levels) in <class:Contact>'
app/models/user.rb:31:inupdate_contact’

The calling code is here:

  searchable do
    string :category do
      self.category.name
    end
  end

Category is supposed to be an instance of ContactCategory, and what I think I need is to set self.category to the default if its nil. I tried this to fix it:

  after_initialize :set_defaults

  def set_defaults
    self.category = ContactCategory.first if self.category.nil?
  end

I also tried:

  def after_initialize
    self.category = ContactCategory.first if self.category.nil?
  end

And I’ve tried:

  before_create :set_defaults

  def set_defaults
    self.category = ContactCategory.first if self.category.nil?
  end

Someone else has suggested putting this logic in before_save, but there is already a before_save that has this logic in it, that’s where I saw what the author had intended to be the default in the first place.

UPDATE:

This question is silly now that I see what’s wrong. I was assuming that the assignment statement never ran because I assumed ContactCategory.first was also not nil. Sadly, everything here is working as expected. The moral of the story is:

All of the hooks I was using to set the default were working correctly. I would recommend using them to set a default using ActiveRecord.

Answer 1

I tend to use the before_create callback for setting default values and whatnot, but here’s the full list of ActiveRecord callbacks from the RoR API docs. You’ll notice after_initialize doesn’t work like exactly its name suggests:

Lastly an after_find and after_initialize callback is triggered for each object that is found and instantiated by a finder, with after_initialize being triggered after new objects are instantiated as well.

You probably want to use before_save or before_create instead.