pivotal-cloudplanner/also_validates

Validate associated models, and aggregate their errors onto the primary model

AlsoValidates

An ActiveModel validator that validates associated models, copying any errors from composed models up to their parent.

Installation

Add this line to your application's Gemfile:

gem 'also_validates'

And then execute:

$ bundle

Or install it yourself as:

$ gem install also_validates

Usage

Given existing models with their own validations:

class Beer
  include ActiveModel::Validations
  attr_accessor :hops
  validates_presence_of :hops

  def initialize(attrs = {})
    @hops = attrs[:hops]
  end
end

class Belly
  include ActiveModel::Validations
  attr_accessor :button
  validates_presence_of :button

  def initialize(attrs = {})
    @button = attrs[:button]
  end
end

And you need a model that composes those models:

class MonsterTruckRally
  include ActiveModel::Validations

  attr_accessor :beer, :belly, :truck_count

  validates_presence_of :truck_count
  also_validates :beer, :belly

  def initialize(attrs = {})
    @beer = attrs[:beer]
    @belly = attrs[:belly]
    @truck_count = attrs[:truck_count]
  end
end

Calling valid? on an instance of monster truck rally, will run validations on both the monster truck rally as well as any models specified by also_validates. If there are any validation errors on the composed model, they are copied up (to the "base") of the parent model (in this case a MonsterTruckRally).

Note: Currently does not pass the attribute information (the field of the composed model) along to its parent. Errors are added to "base".

Only supported option currently is allow_nil: true:

also_validates :beer, :belly, allow_nil: true

Which, as the option states, allows nil values and will not attempt to validate those models.

Contributing

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Added some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request