http://qs321.pair.com?node_id=634535


in reply to Re^3: eval "require $class" seems wrong (::)
in thread eval "require $class" seems wrong

Okay, well, so in the general case (including '::' in module names), the non-string-eval way to do it seems to be: 

# turn $class name into $path
my $class = 'Some::Class';
my $path  =  $class;
$path     =~ s/::/\//g;
$path    .=  '.pm';

# check if $path already loaded
if ( not exists $INC{$path} ) {

    # do block eval on $path
    eval { require $path };
    die "Can't load $class: $@" if $@;
}

# if we make it here, we can use $class
my $obj = $class->new;

[download]

Replies are listed 'Best First'.
Re^5: eval "require $class" seems wrong (code)
by tye (Sage) on Aug 22, 2007 at 23:01 UTC

    The choices of code I posted over 2 hours ago are all shorter, don't make your one minor mistake, and don't waste code making duplicate checks of %INC nor repeating parts of the error message that will be in $@. But, yeah, that's the general idea. :)

    - tye        

[reply]
      Sorry, what's the minor mistake? I'm trying to figure out how to do this correctly. I know the bit I wrote is more verbose (I did that for clarity), but of course I want to avoid duplicate %INC checks, so could you please explain? Thanks!
[reply]

        Did you compare the code? It isn't much code at all, so I'd think that should be your first approach.

        The minor mistake was lack of support for modules like D'oh and Acme::Don't (hence the emphasis).

        but of course I want to avoid duplicate %INC checks, so could you please explain?

        I'm at a loss. What don't you understand about duplicate %INC checks when comparing my code examples to yours?

        - tye        

[reply]

In Section Seekers of Perl Wisdom