NSCodable Module for RubyMotion serializable / NSCode -able classes

example.rb

# This is an example of using the NSCodable module.
class Post
  include NSCodable

  attr_accessor :id, :message
end

# Create a new post.
post = Post.new(:id => 4, :message => 'Some random message')

# Serialize the post using NS Archiver.
post_as_data = NSKeyedArchiver.archivedDataWithRootObject(post)

# Deserialize the post using NS Unarchiver.
post2 = NSKeyedUnarchiver.unarchiveObjectWithData(post_as_data)

# Save the post to the user's cache.
defaults = NSUserDefaults.standardUserDefaults
defaults["saved_post"] = post_as_data

ns_codable.rb

# Simply include this module into your classes that you want to be encoded with NSCode (serialized for temporary cache).
module NSCodable

  # Accepts any public property assignment via hash initialization.
  def initialize(attributes = {})
     attributes.each do |key, val|
      self.public_send("#{key}=", val)
    end
  end

  # Initilizes an object using the NSDecoder.
  def initWithCoder(decoder)
    self.init
    # Loop through the attribute writers.
    methods.grep(/\w=:$/).each do |method|
      # Extract the key (attribute name).
      key = method.to_s.sub('=:', '')
      # Decode the attribute.
      self.send(method, decoder.decodeObjectForKey(key))
    end
    self
  end

  # Encodes an object using the NSCode encoder.
  def encodeWithCoder(encoder)
    # Loop through the attribute writers.
    methods.grep(/\w=:$/).each do |method|
      # Extract the key (attribute name).
      key = method.to_s.sub('=:', '')
      # Encode the attribute.
      encoder.encodeObject(self.send(key), forKey: key)
    end
  end

end