John Johnson
7/17/2006 7:07:00 PM
> Daniel Berger wrote:
> Well, the idea is that the 3rd party software is going to be using
> whatever classes it has always used, so just creating a subclass doesn't
> get me anywhere because the 3rd party app (i.e. Rails) doesn't give a
> hoot about my BigNozzleFiretruck.
You could use a factory for that, and allow the plugin to override the
factory's creater method.
#!/usr/bin/env ruby
class FireTruck
def say
puts "truck"
end
end
class FireTruckFactory
def FireTruckFactory.create
return FireTruck.new
end
end
# First plugin
class Pumper < FireTruck
def say
puts "Pumper here."
end
end
class FireTruckFactory
def FireTruckFactory.create
return Pumper.new
end
end
# Second plugin
class HookAndLadder < FireTruck
def say
puts "Hook and ladder here."
end
end
class FireTruckFactory
def FireTruckFactory.create
return HookAndLadder.new
end
end
#try it
ft = FireTruckFactory.create
ft.say # => Hook and ladder here.
Regards,
JJ