From: unexist <unexist@...>
Date: 2010-10-27T04:33:06+09:00
Subject: Re: require in instance_eval


---- On Tue, 26 Oct 2010 18:35:58 +0200 Jeremy Bopp  wrote ---- 

>You can call require from anywhere, be it within a class definition, a 
>method, or even an eval statement. In all cases the general expectation 
>is that require loads the file into the global namespace rather than 
>into the scope of the calling code. 

Yeah this makes sense, but it still surprised me. I thought it will require it in the
current scope. So for proper sandboxing you need to change require.

>Have you tried loading the contents of the file as a string and then 
>passing the string to eval rather than call require on the file? I 
>think that might do what you want. 

I am using ruby as embedded scripting language in my window manager and for
the config file. Recently I decided moving the DSL parts of the config into a kind of
sandbox for evaling and to avoid polluting the global namespace.

Some of the users splitted their config into several parts and included them with
require and require_relative.

>What exactly is the error message when you try to use require_relative?

When I use the example from before and just change the require to
require_relative in read.rb I get this error:

read.rb:3:in `require_relative': cannot infer basepath (LoadError)
       from read.rb:3:in `<main>'
       from foobar.rb:11:in `instance_eval'
       from foobar.rb:11:in `<main>'

Which probably makes sense, since the basepath is undefined, but it a pita. ;)

With best regards

Christoph