Re: Program structure: subs vs modules vs Selfloader

Here's one solution:

# Give largesub and its entourage their own module
package ModuleWithLargeSub;

sub smallsub {
...process...
}

sub largesub {
    my ($e, $f, $g, $h) = @_;
    
    my $foo = &smallsub($e);    
    
    ...process...
    return \@AoH;
} 
   
1;

# Then in the cgi script:

#!/usr/bin/perl
use strict;
my $run_large_sub;
...etc...
...initiate variables...
...HTML::Template setup...

my $AoH;
if($run_large_sub) {
    require ModuleWithLargeSub;
    $AoH = ModuleWithLargeSub::largesub($a, $b, $c, $d);
}

$template -> param( todisplay => $AoH );
print $template->output();    
exit();
[download]

Also, serioulsy consider breaking the large sub into smaller ones!
:-)

Comment on Re: Program structure: subs vs modules vs Selfloader Download Code

Replies are listed 'Best First'.
Re^2: Program structure: subs vs modules vs Selfloader by bradcathey (Prior) on Jun 20, 2004 at 17:31 UTC
Arunbear, thanks for the example. However, if I'm permitted, I have a follow-up question: does coding it the way you do, by "requiring" the module only if the condition is met, only load the module when it runs? Normally I reference the module like this: `use SomeModule.pm` [download] at the start of my program, right after the shebang. Thanks. Update: Well, I Googled and found this informative piece on modules, libraries, etc. I see now that Perl doesn't deal with a `require` until it comes across it in the code. —Brad "Don't ever take a fence down until you know the reason it was put up. " G. K. Chesterton	[reply] [d/l] [select]
Re^3: Program structure: subs vs modules vs Selfloader by vek (Prior) on Jun 20, 2004 at 18:31 UTC
If you `use` a module, Perl deals with it at compile time. If you `require` a module, Perl deals with it at run time. I typically like to `use` a module because it allows me to check everything via a `perl -c someprog.pl` after I've finished coding. It I used `require` instead, I wouldn't find out that something was wrong until I ran the program for the first time. YMMV, just my own personal preference. `require` is handy though if your program needs to do something based on whether you have a module installed on your system. You can test for this at runtime. `#!/usr/bin/perl -w use strict; # do we have FOO::Bar on this system? eval { require FOO::Bar }; if ($@) { # FOO::Bar not installed } else { # FOO::Bar installed }` [download] -- vek --	[reply] [d/l] [select]