Last active
October 25, 2017 21:33
-
-
Save prodis/077e2c8de166090cd939e9db8f92e5d0 to your computer and use it in GitHub Desktop.
Module to initialize required attributes
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
module InitAttributes | |
def self.included(base) | |
base.send(:include, InstanceMethods) | |
base.extend(ClassMethods) | |
end | |
module InstanceMethods | |
def initialize(attributes) | |
init_instance_variables(self.class.accessor_attributes, attributes) | |
init_instance_variables(self.class.reader_attributes, attributes) | |
end | |
private | |
def init_instance_variables(required_attributes, given_attributes) | |
required_attributes.each do |attr| | |
instance_variable_set("@#{attr}", given_attributes.fetch(attr)) | |
end | |
end | |
end | |
module ClassMethods | |
def accessor_attributes | |
@accessor_attributes ||= [] | |
end | |
def reader_attributes | |
@reader_attributes ||= [] | |
end | |
private | |
def init_attr_accessor(*attributes) | |
attr_accessor(*attributes) | |
@accessor_attributes = attributes | |
end | |
def init_attr_reader(*attributes) | |
attr_reader(*attributes) | |
@reader_attributes = attributes | |
end | |
end | |
end | |
class Akira | |
include InitAttributes | |
init_attr_reader :one | |
init_attr_accessor :two | |
def do_something | |
puts 'Doing something...' | |
end | |
end | |
ls Akira | |
# InitAttributes::ClassMethods#methods: accessor_attributes reader_attributes | |
# Akira#methods: do_something one two two= | |
# instance variables: @accessor_attributes @reader_attributes | |
akira = Akira.new(one: 1, two: 2) | |
# => #<Akira:0x007ff1da152e48 @one=1, @two=2> | |
ls akira | |
# Akira#methods: do_something one two two= | |
# instance variables: @one @two | |
Akira.new(one: 1) | |
# => KeyError: key not found: :two |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment