#!/usr/bin/perl
use strict;
use warnings;
use CGI;
use Template;
my $cgi = CGI->new;
my $template_vars = {
animals => [
sort qw/lion tiger bear pig porcupine ferret zebra gnu ostrich
emu moa goat weasel yak chicken sheep hyena dodo lounge-lizard
squirrel rat mouse hedgehog racoon baboon kangaroo hippopotamus
giraffe
/
],
};
# Recover the previous animals from the magic cookie.
# The cookie has been formatted as an associative array
# mapping animal name to the number of animals.
my %zoo = $cgi->cookie( 'animals' );
# Recover the new animal(s) from the parameter 'new_animal'
if ( my @new = $cgi->multi_param( 'new_animals' ) ) {
# If the action is 'add', then add new animals to the zoo. Otherwise
# delete them.
foreach ( @new ) {
if ( $cgi->param('action') eq 'Add' ) {
$zoo{$_}++;
} elsif ( $cgi->param('action') eq 'Delete' ) {
$zoo{$_}-- if $zoo{$_};
delete $zoo{$_} unless $zoo{$_};
}
}
$template_vars->{zoo} = \%zoo if keys( %zoo );
}
# Add new animals to old, and put them in a cookie
my $the_cookie = $cgi->cookie(
-name => 'animals',
-value => \%zoo,
-expires => '+1h'
);
my $tt = Template->new;
# Print the header, incorporating the cookie and the expiration date...
print $cgi->header(
-cookie => $the_cookie,
-type => 'text/html',
-charset => 'utf-8',
);
$tt->process( \*DATA,$template_vars ) or warn $tt->error;
__DATA__
Animal crackers
Animal Crackers
Choose the animals you want to add to the zoo, and click "add".
Come back to this page any time within the next hour and the list of
animals in the zoo will be resurrected. You can even quit the browser
completely!
Try adding the same animal several times to the list. Does this
remind you vaguely of a shopping cart?
| Add/Delete | Current Contents
|
|---|
|
|
[% IF zoo.defined %]
[% FOREACH animal IN zoo.keys.sort %]
- [% zoo.$animal %] [% animal %]
[% END %]
[% ELSE %]
The zoo is empty.
[% END %]
|