Re^2: Modification of @ISA at run time

[jkeenan1]

Here is a cleaned-up version of Damian's example, along with a test.

package Astro::Data::Astrological;
use strict;
use warnings;
use base qw( Astro::Data::Scientific );

sub new {
    my $class = shift;
    my $self = bless( {}, $class );
    return $self;
}

sub hello {
    my $self = shift;
    my $msg = 'Hello, astrologically!';
    return $msg;
}

1;


package Astro::Data::Scientific;
use strict;
use warnings;

sub new {
    my $class = shift;
    my $self = bless( {}, $class );
    return $self;
}

sub hello {
    my $self = shift;
    my $msg = 'Hello, scientifically!';
    return $msg;
}

sub goodbye {
    my $self = shift;
    my $msg = 'Goodbye, anyway';
    return $msg;
}

1;

package Astro::Data;
$VERSION = '0.01';
use strict;
use warnings;
use base qw(
    Astro::Data::Astrological
    Astro::Data::Scientific
);

sub new {
    shift; # off class name

    if (-f "$ENV{HOME}/xyz") {
        return Astro::Data::Astrological->new();
    }
    else {
        return Astro::Data::Scientific->new();
    }
}

1;

# t/001_load.t
use strict;
use warnings;
use Test::More
# tests => 2;
qw(no_plan);
use File::Copy;
use Carp;

BEGIN { use_ok( 'Astro::Data' ); }

my $home = "/Users/jimk";

my $obj1 = Astro::Data->new ();
isa_ok($obj1, 'Astro::Data::Astrological');
like($obj1->hello, qr/astrologically/,
    "hello method returned correct string"); 
like($obj1->goodbye, qr/anyway/,
    "goodbye method returned correct string"); 

move ("$home/xyz", "$home/abc")
    or croak "Unable to rename xyz:  $!";
ok( (-f "$home/abc"), "rename first-a");
ok(! (-f "$home/xyz"), "rename first-b");


my $obj2 = Astro::Data->new ();
isa_ok($obj2, 'Astro::Data::Scientific');
like($obj2->hello, qr/scientifically/,
    "hello method returned correct string"); 
like($obj2->goodbye, qr/anyway/,
    "goodbye method returned correct string"); 

move ("$home/abc", "$home/xyz")
    or croak "Unable to rename abc: $!";
ok( (-f "$home/xyz"), "rename second-a");
ok(! (-f "$home/abc"), "rename second-b");

I hope this example is (a) correct and (b) useful to the next person who wonders about this.

Jim Keenan