From: Tobias DiPasquale <anany@...>
Date: 2001-12-03T14:57:59+09:00
Subject: [ruby-talk:27322] HELP!! loading multiple classes from a file???

Hi all,

	I really need the community's help on this one. Is it possible to load 
multiple classes after a Ruby program has started? Here is what I am 
trying to do: I need to load an arbitrary number of classes from their 
respective files after I start a Ruby program, where other objects have 
already been instantiated. Please note the results of the following 
little test program:

<super_failure_example>
% pwd
/home/anany/RubiCTM

% ls -l
total 88
-rw-rw-r--    1 anany    anany          50 Dec  3 00:36 a.rb
-rw-rw-r--    1 anany    anany          49 Dec  3 00:37 b.rb
-rw-rw-r--    1 anany    anany          49 Dec  3 00:37 c.rb
-rw-rw-r--    1 anany    anany          75 Dec  3 00:28 klass_spec.conf
-rw-rw-r--    1 anany    anany         305 Dec  3 00:37 propogate.rb
...remaining output removed for brevity

% cat klass_spec.conf
/home/anany/RubiCTM/a.rb
/home/anany/RubiCTM/b.rb
/home/anany/RubiCTM/c.rb

% cat a.rb b.rb c.rb
class A

  def initialize
   @value = "a"
  end
end

class B

  def initialize
   @value = "b"
  end
end

class C

  def initialize
   @value = "c"
  end
end

% cat propogate.rb
klass_file = "klass_spec.conf"

i = 0
a = []

IO.foreach(klass_file) { |line|

  # load each file and resolve classes
  begin
   ret = require line
  rescue LoadError
   puts "error reading: " + line + ": " + $!
  ensure
   puts "return value: " + ret unless ret == nil
  end

  # for now, just keep track of those successfully loaded
  if ret
   i += 1
   a[i] = line
  end
}

puts "Array ==> [" + a.to_s + "]"

% ruby propogate.rb
error reading: /home/anany/RubiCTM/a.rb
: No such file to load -- /home/anany/RubiCTM/a.rb
error reading: /home/anany/RubiCTM/b.rb
: No such file to load -- /home/anany/RubiCTM/b.rb
error reading: /home/anany/RubiCTM/c.rb
: No such file to load -- /home/anany/RubiCTM/c.rb
Array ==> []

</super_failure_example>

If it makes a difference, here are my machine specs:
OS: RedHat 7.2 (kernel 2.4.7-10)
CPU/speed: Pentium III/800 MHz
ruby --version: 1.6.5
ruby ./configure options: none

The goal of this is to be able to have requests come in from a dRuby 
naming service (from client --> naming service --> object container --> 
client) and have the container, who has already loaded the class 
definitions for the objects requested, just instantiate one of the 
objects and return it to the client.

I was trying to find Marshal#load's source code (in Ruby), but it 
appears to be in libruby.so. (no help there) Likewise, Kernel::load is 
unsuitable as load _executes_ a file, whereas all I want to do is load a 
class(es) from a file. Kernel::require seems to be my only hope, but 
even this is erroring out on a simple (?) task like the above.

Anybody know why the above code doesn't work, or how to make it work?
-- 

0100001101000010010000110100011101110101
<< Tobias DiPasquale >>
-=[ Solaris Systems Administrator ]=-
Villanova University ECE Dept.
mailto: anany@ece.vill.edu
-=[ Applications Engineering Consultant ]=-
BCS Solutions, Inc.
mailto: tdipasquale@bcssinc.com
0100001101000010010000110100011101110101