FormAttribute

A lightweight gem for adding typed attributes to plain objects

Installation

Add this line to your application's Gemfile:

gem 'form_attribute'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install form_attribute

Usage

Add the line extend FormAttribute to your class, then start defining attributes as in the example below:

class Person
  extend FormAttribute

  attribute :name, String
  attribute :role, String, default: 'user'
  attribute :employee, Boolean, default: true
  attribute :contact, [String, Integer]
  attribute :date_of_birth, Time
end

Attribute definitions follow the pattern attribute <name>, <types>, <options>. <types> can be an array of allowed types or a single allowed type. When setting the value, it will be validated against this list of types and will raise a TypeError if the value being set is not one of these types.

Attributes on an object can be read with Class.attributes

Person.attributes
=> [:name, :role, :employee, :contact, :date_of_birth]

The type of an attribute can be read with Class.type_of(<attribute>)

Person.type_of :name
=> [String]

Person.type_of :contact
=> [String, Integer]

The default value of an attribute can be read with Class.default_for(<attribute>)

Person.default_for :role
=> "user"

Each attribute is available as a method on the object created.

person = Person.new
=> #<Person name: nil, role: "user", employee: true, contact: nil, date_of_birth: nil>

person.name
=> nil

person.role
=> "user"

Setting attributes is also available as a method

person.name = 'John Smith'
=> "John Smith"

person.name
=> "John Smith"

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec 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/hex-event-solutions/form_attribute. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

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

Code of Conduct

Everyone interacting in the FormAttribute project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.