Assigning attr_accessor using fixtures in Rails

Question

I have a simple Rails 3 model, with an attr_accessor that doesn't have a field in the database, and I need to set it up using fixtures, because of my initialization setup.

But when I try it, I get an error about the unknown column.

Is there another way to do this?

My model:

class Timeslot < ActiveRecord::Base
    attr_accessor :interval
    after_initialize :init

    def init
        self.interval ||= 15
        self.start_time ||= Time.local(0, 1, 1)
        self.end_time = self.start_time.advance :minutes => self.interval
    end
end

Answer 1

Fixtures add data directly into the database. If you want to pass data to a model instead, consider using factories (Factory Girl is a good library).

You may already have a big investment in fixtures, but factories are well worth a look.

Answer 2

Fixtures are end state. Meaning, what's in your database is output after you've called attr_accessor. So end_time would always be calculated for you if you were using it in a test like @timeslot = timeslots(:your_name_of_fixture). You don't need to worry about them in the Fixture, except for when you are setting it up.

Now, I've not seen an after_initialize before, but i see it's a callback function. To me, you are setting an interval in a view. Probably not programmatically (unless it's that default 15 minutes there).

Switching to a before_save callback (if you want your people to be able to change intervals on edit too) like:

class Timeslot < ActiveRecord::Base
    attr_accessor :interval
    before_save :set_times
    def set_times
        self.interval ||= 15
        self.start_time ||= Time.local(0, 1, 1)
        self.end_time = self.start_time.advance minutes: self.interval
    end
end