Datamapper DataMapper

This doesn't work as expected, because it is inside a Foo class:

class Foo
  class Author < DataMapper::Base
    has_many :articles
  end
  class Article < DataMapper::Base
    belongs_to :author
  end
end

------

I looked for a solution, found two problems:

1. in associations/has_n_association.rb

1.1. There is a problem with Kernel.get_const() in associated_constant(). It expect only "Foo" or "Author", but fails when get "Foo::Author".

The solution is to split the string constant by :: and start from the top Object:

def associated_constant
  @associated_constant || begin
    klass = Object
    associated_constant_name.to_s.split( /::/ ).each { |const_name|
      const_name = const_name.to_sym
      if klass.const_defined?( const_name )
        klass = klass.const_get( const_name )
      else
        raise "constant #{klass.to_s}::#{const_name} missing"
      end
    }
    @associated_constant = klass
  end
end

1.2. Then if :class or :class_name is not defined, associated_constant_name() guess it from @association_name. This works when Article or Author is the top class, but not if it is inside Foo. The solution could be to use the same parent classes as the @constant and guess it like this

 def associated_constant_name
    #...
    else
      @associated_constant_name = @constant.to_s.split( /::/ )[0..-2].join( '::' ) + '::' + Inflector.classify (@association_name)
    end
    #...
 end

2. in dependency_queue.rb

In resolve! there is the same problem as in 1.1. The solution could be again to start from the top:

    def resolve!
      @dependencies.each_pair do |class_name, callbacks|
        klass = Object
        class_name.split( /::/ ).each { |const_name|
          const_name = const_name.to_sym
          if klass.const_defined?( const_name )
            klass = klass.const_get( const_name )
          else
            raise "constant #{klass.to_s}::#{const_name} missing"
          end
        }
        # klass found
        callbacks.each do |b|
            b.call(klass)
        end
        callbacks.clear
      end
    end

Maybe it would be better to create Object.full_const_get() which could resolve 'Foo::Author' (I think it is in more places)