On Jan 21, 2011, at 3:41 PM, Nick Sutterer wrote:
> By accident I solved this with a 10-liner months ago, why not use
> something like that?
> https://github.com/apotonick/hooks/blob/master/lib/hooks/inheritable_attribute.rb
>
> It's simple, clean and does exactly what you expect.
>
Well, as long as "what you expect" doesn't involve keeping anything more
complicated than a flat Hash/Array/etc in the class variable:
irb --> a = { :key_1 => 1, :key_2 => ['x','y'] }
==> {:key_1=>1, :key_2=>["x", "y"]}
irb --> b = a.clone
==> {:key_1=>1, :key_2=>["x", "y"]}
irb --> b[:key_2] << 'z'
==> ["x", "y", "z"]
irb --> a
==> {:key_1=>1, :key_2=>["x", "y", "z"]}
Object#clone solves the problems caused when you add a key to hash b in this
example, but it doesn't completely separate the objects. This code does:
totally_cloned = Marshal.load(Marshal.dump(source))
but that's fairly inefficient and fails disastrously if an object that can't be
marshalled is involved (Procs, for instance).
I can't really decide whether doing the clone causes results that are more or
less surprising than the existing version.
--Matt Jones
--
You received this message because you are subscribed to the Google Groups "Ruby
on Rails: Core" group.
To post to this group, send email to rubyonrails-core@googlegroups.com.
To unsubscribe from this group, send email to
rubyonrails-core+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/rubyonrails-core?hl=en.
