CODEWITHSUNDEEP
rubyclassclone
Nathan
Nathan

Reputation: 7855

How to make Class.clone or Class.dup work in ruby?

I have a model called Client and I would like to clone it in certain cases where clients (the real world kind) have modifications that require class level changes.

For example, if I have:

class Client
  set_table_name :clients

  def some_method
    puts "Hello"
  end
end

Then if I have the following:

module ClientA
  def some_method
    puts "World"
  end
end

I would expect that I could clone (or dup) the class, then include the module to overwrite the method some_method.

But here's what happens in my production console:

> CA = Client.dup
> CA.singleton_class.send(:include, ClientA) # Or just CA.send(:include, ClientA)
> client = CA.new
> client.some_method
=> "Hello" # Expected "World"

Is there a trick to this?

Upvotes: 1

Views: 497

Answers (2)

aceofspades
aceofspades

Reputation: 7586

Instead of Client.dup use Class.new(Client), which subclasses Client.

If you're trying to avoid that, this seems to work with Client.dup:

CA.send(:define_method, :some_method) do 
  puts "World"
end

Upvotes: 1

Jesse Wolgamott
Jesse Wolgamott

Reputation: 40277

If you're wanting to override specific classes with a module's data, you want to extend it.

client = Client.new
client.extend(ClientA)
client.some_method
=> "World"

You can see it work here: http://rubyfiddle.com/riddles/7621e

Upvotes: 1

Related Questions