Method attributes

class-mattr gem provides simple way to set and get method attributes.

Installation

to install

gem install class-mattr

or in Gemfile

gem 'class-mattr'

and to use

require 'class-mattr'

How to use

include ClassMattr
define method attributes via mattr.name argument
get them via mattr :name (class and instance method provided)

class Foo
  include ClassMattr

  mattr.name 'Test method'
  mattr.opt  guest: true
  def test
  end

  def get
    mattr :test # get :test method attributes
  end
end

Real world scenario

Protect all urls in a way that user has to have a session (current_user is defined), but allow to bypass that rule if mattr.guest_access is defined

Optionaly you can define array of method names as sysbols for mattr method, to be able to use them without mattr. prefix.

class ApplicationController < ActionController::Base
  include ClassMattr

  # allow usage without mattr prefix
  mattr [:guest_access]

  before_action do
    # get all method attributes
    opts = mattr params[:action]

    if !opts[:guest_only] && !current_user
      redirect_to '/login', info: 'You must log in to access this resource'
    end
  end
end

class UserController < ApplicationController
  # mattr.guest_access, aliased trough class method
  # default argument is true, if nil defined
  guest_access
  def login
    # ...
  end

  def profile
    # ...
  end
end

Manual hash get

If you need, you can get method attributes hash manualy

class ClassA
  include ClassMattr

  mattr.foo 123
  mattr.opt name: 'Dux'

  mattr.get_hash # { foo:123, name: 'Dux' }
end

Ruby metaprograming fun

ClassMattr is exported as a module and a function too. If call ClassMattr in a function context you can include and define exported methods in one go as ClassMattr :exported_method1, :exported_method2.

class ApplicationController < ActionController::Base
  # same as
  # include ClassMattr
  # mattr [:guest_access]
  ClassMattr :guest_access

  before_action do
    opts = mattr :login # { guest_access: true }
  end
end

class UserController < ApplicationController
  guest_access
  def login
    # ...
  end
end

Dependency

none

Development

After checking out the repo, run bundle install to install dependencies. Then, run rspec to run the tests.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/dux/class-mattr. 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.