AbleAttrs

Capable attributes for your Ruby classes. Provides a DSL to define attributes whose values can be initialized, type-coerced, and transformed from common inputs upon setting.

While there are other "better-setter" gems out there, AbleAttrs attempts to do more with less, minimize runtime dependencies (currently none), and impose a very small API footprint on the classes that implement it: .able_attrs, ._able_attr_definitions, #initialize, and #apply_attrs

Installation

Add this line to your application's Gemfile:

gem 'able_attrs'

And then execute:

$ bundle

Or install it yourself as:

$ gem install able_attrs

Usage

Currently, the system supports five built-in type-coercions (array, boolean, date, float, integer, and string) which are accessible via the able_attrs definition DSL.

You may also use your own type-coersion by supplying it to the more generic attr definition. The type that you supply must respond to import and default.

All coersion/transformation occurs within the setter. The setter methods added can be overridden and accessed via super

class MyForm
  include AbleAttrs

  sanitized_string = Module.new do
    def self.import(value)
      value.to_s.strip.downcase
    end

    def self.default
      ''
    end
  end

  able_attrs do
    boolean :accepts_terms
    date :birthday
    string :first_name, :last_name, opts: {strip: true}
    attr :email, :login, type: sanitized_string
    integer :number_of_cats
  end

  def number_of_cats=(value)
    super
    if number_of_cats.to_i < 0
      super(0)
    end
  end
end

response = MyForm.new({
  email: " Larry@example.com", login: "lazylarry", birthday: "1980-01-02",
  first_name: "Larry", last_name: " Friendly", number_of_cats: "3"
})

response.email
#=> "larry@example.com"

response.last_name
#=> "Friendly"

response.accepts_terms
#=> false

response.birthday
#=> #<Date: 1980-01-02 ((2444241j,0s,0n),+0s,2299161j)>

response.number_of_cats
#=> 3

response.apply_attrs("number_of_cats" => '-1')
response.number_of_cats
#=> 0

Development

After checking out the repo, run bin/setup to install dependencies. Then, run bin/rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/agileleague/able_attrs. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.

License

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