Re: Skeleton For Import to Package?

[almut]

so, how do I get the arguments

Inspect @_ in the import routine.

sub import {
    my $pkg = shift;  # "cacher" in this case
    my $dir = $_[0] || "/tmp";
    setup_cachehash($dir);
    ...
}

sub setup_cachehash {
    ...
}

[iaw4]

thanks. I just realized that my error comes from another source. How do I force the "import" to be the first executed statement? ... answer below

package cacher;
use strict;
use warnings;
use warnings FATAL => qw{ uninitialized }; # larry, this should have b
+een part of warnings.

use base 'Exporter';
our @EXPORT = ("pdfpagenum");

BEGIN {
  my $saved_pkg_args="undefined";

  sub import {
    print "import args: ".join("|", @_)."\n";
    $saved_pkg_args= $_[1];
    print "in import, saved args '$saved_pkg_args'\n"; 
  }

  sub test { print STDERR "in test, you have saved '$saved_pkg_args'\n
+"; }

  print "this should executed after the import: $saved_pkg_args.\n"
}

1;

I guess I should just call everything I want to be main code from the import statement itself. still strange that import() is not the first thing called.

[almut]

How do I force the "import" to be the first executed statement?

You can't (at least not with the desired arguments), because cacher->import(...) is being called after the module has been required — at which point any code of the module outside of subroutines will already have been run. That's how use works...

Update: it's maybe worth mentioning that import is not being called at all if you say use cacher ();. If that's an issue in your case, you might want to setup %cachehash with a default directory at the time the module is being required. Then, in case import is being called, just re-initialize %cachehash with the directory specified as the argument to use.  Kind of like this:

sub import {
    ...
    setup_cachehash($dir) if $dir;
}

sub setup_cachehash {
    ...
}

setup_cachehash("/tmp");  # default

(From a performance point of view, doing things twice is of course suboptimal...)

P.S.: if you use Exporter in the same package, you probably want to explicitly call its import routine with the appropriate arguments (first arg = your package name), because normally the import method will be inherited from Exporter. In other words, Exporter's import will no longer be called (automatically) when you implement import yourself...