Thanks for the replies!

Botp, your "cheat" does indeed allow you to use require again to load  he source file, but this is actually doing the same thing as using  
Kernel.load. It's just interpreting the contents of foo.rb again,  
effectively reopening class Foo. Kernel.load is just like require,  
only require checks $LOADED_FEATURES I guess before it blindly  
interprets the content of your file again. Kernel.load doesn't do any  uch check; it interprets the file you point it to no matter what.

I did try it, but unfortunately DataMapper still complains about  
missing properties and such on existing objects after the reload. And  he problem still remains that we are not truly "reloading" the  
class ... we're just reopening it, adding or overwriting methods, just  ike we might in an IRB session.

I did try to go the Marshal route, but Marshal.dump chokes when trying  o dump most of my objects with "TypeError: can't dump hash with  
default proc". I don't know exactly what that's referring to (the  
stack trace is useless), but it probably has something to do with a  
DataMapper feature. Marshal seems to be pretty unreliable for any kind  f non-trivial object, and I think doing any kind of "deep copy" on my  bjects will lead to weird duplication issues with their associations  nyway. e.g. two Player objects in the same Room need to refer to the  ame object_id for player.room (at least, that's the assumption I'm  
designing under right now to prevent hitting the DB constantly). If I  o a deep copy as Marshal.dump(player) would do, I'll end up with the  layers referring to two brand new, different copies of Room objects.  hich is bad, I think.

Though it's possible that I'm making a mistake by relying on the Room  bjects staying in-memory. I need to read up on how garbage collection  orks.

At any rate, I'm about to give up on this idea unless anyone has any  
other suggestions. Thanks!

Brent


On Aug 23, 2008, at 12:05 AM, Peñá, Botp wrote:

> From: Brent Dillingham [mailto:brentdillingham / gmail.com]
> # ...
> #      >> puts File.read('foo.rb')
> #      class Foo
> #        def hello
> #          "Hello, world!"
> #        end
> #      end
> #      => nil
> #      >> require 'foo'
> #      => true
>
> ok. you used require
>
> #      # Reload the file using remove_const and Kernel.load
> #      >> Object.send(:remove_const, :Foo)
> #      => Foo
> #      >> Kernel.load('foo.rb')
> #      => true
>
> now you use load.
>
> let us stick to require... ;)
>
> irb(main):001:0> require 'foo.rb'
> => true89
> irb(main):002:0> f=Foo.new
> => #<Foo:0x2900af4>
> irb(main):003:0> f.hello
> => "hello"
>
> ok
>
> irb(main):004:0> require 'foo.rb'
> => false
> irb(main):005:0> f.hello
> => "hello"
>
> as expected, no change.
> let's see if we can cheat ;)
>
> irb(main):006:0> $LOADED_FEATURES
> => ["e2mmap.rb", "irb/init.rb", "irb/workspace.rb", "irb/ 
> context.rb", "irb/extend-command.rb", "irb/output-method.rb", "irb/ 
> notifier.rb", "irb/slex.rb", "irb/ruby-token.rb", "irb/ruby-lex.rb",  readline.so", "irb/input-method.rb", "irb/locale.rb", "irb.rb",  
> "irb/ext/history.rb", "irb/ext/save-history.rb", "foo.rb"]
>
> ah
>
> irb(main):007:0> $LOADED_FEATURES.delete "foo.rb"
> => "foo.rb"
>
> irb(main):008:0> require 'foo.rb'
> => true
> irb(main):009:0> f.hello
> => "new hello"
>
> is that ok?
> ... caveat, i'm not sure if that is documented/supported. maybe,  
> verify fr matz or nobu..
>
> kind regards -botp
>
>