· ruby active-record

Ruby: Getting Active Record validation errors twice

I managed to create an interesting problem for myself while playing around with some code whereby I was ending up with validation errors appearing twice every time I called ‘valid?’ on a specific model.

I figured I was probably doing something stupid and in fact a few replies by Aaron Baldwin on a mailing list thread on ‘rubyonrails-talk’ helped explain exactly what I’d done:

Are you calling require 'employee' anywhere? If so you are likely causing the model to load twice which causes duplicate errors because the validates_presence_of method gets called twice.

I’d put the following code into a controller elsewhere somewhat unnecessarily since it didn’t seem to be picking up the location of my model at the time:


require 'models/code_submission'

class CodeSubmissionsController < ApplicationController
  def new

require doesn’t load a file if it’s already been included but Aaron points out why it does on this occasion:

You are right that "require" will only load the file once. But if you load the class another way calling "require" will load it again.

As I understand it that controller code would also implicitly require ‘code_submission’ by the convention of inserting an underscore between the ‘CodeSubmission’ constant’s names.

We therefore effectively have the following two requires:

require 'code_submission'
require 'models/code_submission'

Which explain how the file gets loaded twice and therefore why the validation method fires twice and therefore creates two errors!

  • LinkedIn
  • Tumblr
  • Reddit
  • Google+
  • Pinterest
  • Pocket