From: Mochi Mochigome <mochi.mochigome@...>
Date: 2010-07-25T22:25:51+09:00
Subject: Re: Design Question

David Masover wrote:
> On Saturday, July 24, 2010 09:24:28 am Mochi Mochigome wrote:
>> Hi guys,
>> 
>> I have a program design question regarding mix-ins.
>> 
>> I currently have 5 modules:
> [...]
>> and a single class which includes all those modules:
>> 
>> class Client
>>   include Authentication, User, Issue, Network, Object
>> end
> 
> That's not bad in and of itself. It depend show big the modules are.
> 
>> So, is there a more elegant way of doing this?
> 
> Separate objects.
> 
> 
> class Authentication
> end
> 
> class User
> end
> 
> class Issue
> end
> 
> class Network
> end
> 
> class Client
> 
>   def initialize
>     @authentication = Authentication.new
>     @user = User.new
>     @issue = Issue.new
>     @network = Network.new
>   end
>   attr_reader :authentication, :user, :issue, :network
> end
> 
> 
> That may or may not work well, depending what you're trying to 
> implement. For
> example, does it make sense to reason about a User or an Issue which 
> stands
> alone, and isn't part of anything else?
> 
> Basically, _is_ a Client a User, or does a Client _have_ a User?
> 
> You may also find that both make sense, sometimes. For example, 
> DataMapper has
> a module that you include (Resource) which extends your class in a 
> number of
> ways to behave like a model object should, but it also ties you into a 
> number
> of separate objects. Some of them obviously shouldn't be part of your 
> class,
> like the repository (represents a database connection). Some of them, 
> though,
> are only about your class -- State, for example -- and of course, you 
> get a
> whole list of properties.
> 
> But what you've got isn't necessarily bad.

After thinking more about it and doing some reading I changed my design 
to something similar to yours but using delegation.

e.g.

require 'forwardable'

module App
  class Client
    extends Forwardable

    def self.user; User.new end
    def_delegators :user, :show, :search

    def show_user
      Client.user.show
    end
    def search_user
      Client.user.search
    end

  end
end

module App
  class User
    .
    .
    .
  end
end

m
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