gistfile1.rb

# The code:

class MerbAuthSliceFullfat::AuthenticatingClient
  include DataMapper::Resource
  
  # Key it
  property :id,             Serial
  # The registration will belong to a user, who will be able to edit the client properties.
  property :user_id,        Integer,  :writer => :protected
end

# The problem:
>> c = AuthenticatingClient.new
=> #<MerbAuthSliceFullfat::AuthenticatingClient id=nil user_id=nil name=nil web_url=nil icon_url=nil api_key=nil secret=nil kind=nil callback_url=nil>
>> c.attributes = {:user_id=>10}
=> {:user_id=>10}
>> c.inspect
=> "#<MerbAuthSliceFullfat::AuthenticatingClient id=nil user_id=10 name=nil web_url=nil icon_url=nil api_key=nil secret=nil kind=nil callback_url=nil>"
>> c.user_id = 10
NoMethodError: protected method `user_id=' called for #<MerbAuthSliceFullfat::AuthenticatingClient:0x2574b60>
	from (irb):5
	from :0