Question

I’m making an task-manager and have an boolean attribute for ‘finished’. I’ve tried to override the setter to implement an ‘finished_at’ date when i toggle ‘finished’ to true.

But i getting some mixed result. It doesn’t work in browser but it will work in my rspec test.

Please help me out.

class TasksController < ApplicationController 
# ...
def update
  # ..
  if @task.update_attributes(params[:task]) # where params[:task][:finished] is true
# ...
end

class Task < ActiveRecord::Base
#...
  def finished=(f)
   write_attribute :finished, f
   write_attribute :finished_at, f == true ? DateTime.now : nil
  end
end

# and in rspec i have
describe "when marked as finished" do
  before { @task.update_attributes(finished: true) }

  its(:finished_at) { should_not be_nil }
  its(:finished_at) { should > (DateTime.now - 1.minute) }

  describe "and then marked as unfinished" do 
    before { @task.update_attributes(finished: false) }
    its(:finished_at) { should be_nil }
  end
end

in browser it executes “UPDATE “tasks” SET “finished” = ‘t’, “updated_at” = ‘2012-10-02 18:55:07.220361’ WHERE “tasks”.”id” = 17″

and in rails console i got the same with update_attributes.

But in rspec with update_attributes i get “UPDATE “tasks” SET “finished” = ‘t’, “finished_at” = ‘2012-10-02 18:36:47.725813’, “updated_at” = ‘2012-10-02 18:36:51.607143’ WHERE “tasks”.”id” = 1″

So I use the same method but it’s only working in rspec for some reson…

---

using latest rails and latest spec (not any rc or beta).

Solution

Not mush i did need to edit. Thanks @Frederick Cheung for the hint.
I did notice i did like “self[:attr]” more than “write_attribute”. Looks better imo.

def finished=(value)
  self[:finished] = value
  self[:finished_at] = (self.finished? ? Time.now.utc : nil)
end

Answer 1

Your setter is passed the values as they are passed to update_attributes. In particular when this is triggered by a form submission (and assuming you are using the regular rails form helpers) f will actually be “0” or “1”, so the comparison with true will always be false.

The easiest thing would be to check the value of finished? after the first call to write_attribute, so that rails can convert the submitted value to true/false. It’s also unrubyish to do == true – this will break if the thing you are testing returns a truthy value rather than actually true (for example =~ on strings returns an integer when there is a match)