Active Model Validates Intersection Of

A custom validation for Active Model that check if an array is included in another one.

Identical to the method validates_inclusion_of from ActiveModel but for array comparison.

Consider an User model that have some set of "default" permissions.

class User < ActiveRecord::Base
  DEFAULT_PERMISSION = ["read", "write", "share"]
  validates_intersection_of :permission, in: DEFAULT_PERMISSION
end

If you want to validate your user based on an array:

user = User.new(permission: ["read", "share"])
user.valid? #true

user = User.new(permission: ["read", "admin"])
user.valid? #false

This active model custom validation is for you!

Installation

Add this line to your application's Gemfile:

gem "active_model_validates_intersection_of"

And then execute:

$ bundle

Or install it yourself as:

$ gem install active_model_validates_intersection_of

If your framework doesn't auto require gems, don't forget to do it after require of active_model gem.

require "active_model"
require "active_model_validates_intersection_of"

Usage

Parameters

• :in - Parameter is required. (Supports: Array, proc and lambda)
• :within - Optional: A synonym(alias) for :in
• :message - Optional: Specifies a custom error message

Validation

You can use the intersection validation in three differents ways: (Feel free to use what you liked more :))

class User < ActiveRecord::Base
  DEFAULT_PERMISSION = ["read", "write", "share"]

  # Using the alias validates_intersection_of
  validates_intersection_of :permission, in: DEFAULT_PERMISSION, message: "invalid permission"
  validates_intersection_of :permission, within: DEFAULT_PERMISSION, message: "invalid permission"

  # proc and lambda support
  validates_intersection_of :permission, in: proc { DEFAULT_PERMISSION }, message: "invalid permission"
  validates_intersection_of :permission, in: lambda { |l| DEFAULT_PERMISSION }, message: "invalid permission"

  # Using the validator explicit:
  validates_with ActiveModelValidatesIntersectionOf::Validator, attributes: [:permission], in: DEFAULT_PERMISSION
  validates_with ActiveModelValidatesIntersectionOf::Validator, attributes: [:permission], within: DEFAULT_PERMISSION

  #Using the validator implicit:
  validates :permission, intersection: { in: DEFAULT_PERMISSION, message: "invalid permission" }
  validates :permission, intersection: { within: DEFAULT_PERMISSION, message: "invalid permission" }

end

License

The gem is available as open source under the terms of the MIT License.

Contributing

First of all, thank you for wanting to help!

1. Fork it.
2. Create a feature branch - git checkout -b more_magic
3. Add tests and make your changes
4. Check if tests are ok - rake spec
5. Commit changes - git commit -am "Added more magic"
6. Push to Github - git push origin more_magic
7. Send a pull request! :heart: