mjacobus / koine-attributes

require 'koine/attributes/builder'

require 'koine/attributes/adapter/base'

# provides the following API

#

# @example using attributes

#   class Person

#     attributes do

#       attribute :name, :string

#       attribute :birthday, :date

#

#       # or

#       attribute :birthday, Koine::Attributes::Adapter::Date.new

#     end

#   end

#

#   peson = Person.new

#   person.name = 'John Doe'

#   person.birtday = '2001-02-31' # Date Object can also be given

#

#   person.name # => 'John Doe'

#   person.birtday # => #<Date 2001-02-31>

#

# @example custom attribute options

#

#     attributes do

#       attribute :name, Koine::Attributes::Adapters::Date.new.with_default('guest')

#

#       # or

#       attribute :name, :string, ->(adapter) { adapter.with_default('guest') }

#     end

#

# @example Constructor for attributes

#

#   class Person

#     attributes initializer: true do

#       attribute :name, :string

#       attribute :birthday, :date

#     end

#   end

#

#   person = Person.new(name: 'John Doe', birthday: '2001-01-31')

#

#   # foo: attribute will raise error with strict mode

#   person = Person.new(name: 'John Doe', birthday: '2001-01-31', foo: :bar)

#

# @example Constructor for attributes withouth strict mode

#

#   class Person

#     attributes initializer: { strict: false } do

#       attribute :name, :string

#       attribute :birthday, :date

#     end

#   end

#

#   # foo will be ignored

#   person = Person.new(name: 'John Doe', birthday: '2001-01-31', foo: :bar)

#

# @example Override constructor

#

#   class Person

#     attr_reader :foo

#

#     attributes initializer: true do

#       attribute :name, :string

#       attribute :birthday, :date

#     end

#

#     def initializ(attributes = {})

#       @foo = attributes.delete(:foo)

#

#       initialize_attributes(attributes) # protected

#     end

#   end

#

#   person = Person.new(name: 'John Doe', birthday: '2001-01-31', foo: :bar)

#   person.foo # => :bar

#

module Koine

  module Attributes

    module Adapter

      autoload :Date, 'koine/attributes/adapter/date'

    end

    Error = Class.new(StandardError)

    def self.included(base)

      base.extend(ClassMethods)

    end

    module ClassMethods

      def attributes(options = {}, &block)

        @builder = Builder.new(target: self)

        class_eval(&block)

        if options[:initializer]

          initializer_options = options[:initializer]

          initializer_options = {} unless initializer_options.is_a?(Hash)

          @builder.build_constructor(initializer_options)

        end

        @builder = nil

      end

      def attribute(name, adapter, &block)

        unless @builder

          raise Error, 'You must call .attribute inside the .attributes block'

        end

        adapter = coerce_adapter(adapter, &block)

        @builder.build(name, adapter)

      end

  end

end