/create_or_update

Write better, more consistent seeds in Rails.

Primary LanguageRubyMIT LicenseMIT

ActiveRecord#create_or_update

"This should be a gem."

Inspired by RailSpikes, this method allows you to call create_or_update on any model. It is especially useful for seeding data.

This method determines whether a record in your seeds already exists, and updates it if so. If it does not already exist, it creates the record.

This version allows you to pass options, such as without_protection: true, to the method. This means that when you seed data, you can update all attributes, including those not made accessible by an attr_accessible method.

This avoids those pesky "mass assignment not permitted" errors during seeds.

Install it!

  • If you don't already have a lib folder inside app (app/lib), create one. This is different from the lib folder in the root of your project.

  • Inside app/lib, create a folder called active_record.

  • Copy create_or_update.rb into app/lib/active_record.

  • If you do not yet have one, in config/initializers, create a file called application.rb.

  • In config/initializers/application.rb, write:

  require 'active_record'
  require 'active_record/create_or_update'

(I'm sorry this isn't a gem. Someday, maybe. I'll totally accept that pull request.)

Use it!

  • Write some seeds as an array of hashes. Make sure to include an :id attribute. Here's an example.

In seeds.rb:

examples = [{id: 1,  title: 'ro',       subtopic_id: 1,  alias: "Renter-Occupied Units (ROUs)"},
            {id: 2,  title: 'roa5',     subtopic_id: 1,  alias: "ROUs Affordable to Households With Incomes Below 50% AMI"},
            {id: 3,  title: 'roa58',    subtopic_id: 1,  alias: "ROUs Affordable to Households With Incomes Between 50-80% AMI"},
            {id: 4,  title: 'roa8',     subtopic_id: 1,  alias: "ROUs Affordable to Households With Incomes Above 80% AMI"},
            {id: 5,  title: 'oo',       subtopic_id: 2,  alias: "Owner-Occupied Units (OOUs)"}]
  • Loop through the seeds, passing them into create_or_update.

In seeds.rb:

examples.each {|record| ExampleModel.create_or_update(record, without_protection: true)

About "without_protection"

You don't have to include without_protection: true. I use it because, in this example, subtopic_id is a protected attribute (aka not attr_accessible), and removing protection gets around "mass assignment not permitted" errors.