Ilmari Heikkinen
4/29/2005 10:32:00 PM
la, 2005-04-30 kello 00:14, Vincent Foley kirjoitti:
> Hi everyone,
>
> I finished playing yet another game of Chrono Trigger the other day,
> and I thought I would look at how I could implement a simple Character
> system in Ruby. I have the following initialize method, but I would
> like to be sure it's not extremely bad style:
>
> class Character
> attr_accessor :strength, :magic, :defense, :magic_defense
>
> def initialize(args = {})
> args.each do |k, v|
> instance_variable_set("@#{k}", v) if respond_to?(k)
> end
>
> methods.grep(/\w=$/).each { |setter|
> getter = setter[0..-2]
> if send(getter).nil?
> send(setter, 0)
> end
> }
> end
> end
>
> So, if I added a :critical_rate accessor, I wouldn't need to modify
> anything else in the initialize method. Also, I don't want nil in any
> attribute. Is this good style? Are there other (maybe better) ways to
> accomplish this? Thank you.
Hello,
I've been using a pretty similar class for my config needs, maybe the
biggest difference is that I'm using a default_config method to get the
default values and to make it work properly with subclassing.
I quite like the respond_to?-check you've got there, think I'll extend
mine by raising a name error if the setter doesn't exist.. or just use a
config block more often :|
Anyhow, here's the class:
class Configurable
def initialize(config = {}, &optional_config_block)
config = default_config.merge(config)
config.each{|k,v| instance_variable_set("@#{k}", v)}
optional_config_block.call(self) if block_given?
end
def default_config
{}
end
end
#subclassing:
class Foo < Configurable
attr_accessor :foo
def default_config
super.merge({
:foo => 10
})
end
end
Foo.new :foo => 5
Foo.new{|f| f.foo = 5 }
class FooBar < Foo
attr_accessor :bar
def default_config
super.merge({
:bar => 20
})
end
end
fb = FooBar.new
fb.foo #=> 10
fb.bar #=> 20