Violated

Violated is a simple gem to do validation of any object.

Installation

Add this line to your application's Gemfile:

gem 'violated'

And then execute:

$ bundle

Or install it yourself as:

$ gem install violated

Usage

Quick start

Add validation to any object by including Violated.new:

class Person
  include Violated.new
end

Then you can define the violations like this:

class Person
  attr_reader :name

  include Violated.new

  violate(:name).when_not :present
end

Or multiple per field:

class Person
  attr_reader :name

  include Violated.new

  violate(:name).when_not :present, [:unique, ->(attr) { uniqueness_check_for_your_application }]
end

You can see if the object is valid:

person.valid?

and lookup the violations if not:

person.violations

Built-in validators

:present

violate(:attr).when_not :present

This fails with a required reason, when the attribute is not present.

:unique

violate(:attr).when_not [:unique, ->(attr) { uniqueness_check_for_your_application }]

This fails with a duplicate reason, when the lambda given returns true.

Creating your own validators

First create the validator, a validator must be at least initialized with a field and it must respond to validate with an object:

class CustomValidator
  def initialize(field)
    @field = field
  end

  def validate(object)
    object.violations << Violated::Violation.new(@field, :custom) if object.violates?(@field)
  end
end

Register it with the Registry:

Violated::Registry.register :custom, CustomValidator

Use it in your class:

class Person
  attr_reader :name

  include Violated.new

  violate(:name).when_not :custom
end

Contributing

1. Fork it ( https://github.com/ThijsWouters/violated/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request