PerlJam has asked for the wisdom of the Perl Monks concerning the following question:

Help me obi-wan you're my only hope. I am making a flashcards script where users can create accounts and store subjects, etc. Well, I have come to a problem diplaying frames using CGI.pm. I have written up a small page that details the problems I am having the errors I have received and that has the code listing (too long for discussion group). If any would be so kind to take a look it would be greatly appreciated. You can find it here.
--Jason Sperry
-------------------------------------------------------
Nothing in the world can take the place of persistence. Talent will not; nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated failures. Persistence and determination alone are omnipotent. --Calvin Coolidge (1872-1933)

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Re: CGI.pm and frames
by chromatic (Archbishop) on Feb 23, 2001 at 07:16 UTC
    Here's the relevant snippet having errors: 
    my %Pages = (
    'Login'           => \&validateAccount,
    'Create Account'  => \&createAccount,
    'User Options'    => \&userOptions,
    'View Flashcards' => \&displayCards,
);

if ( !$q->param ) {
    loginPage();
}
elsif ($q->param('action')) {
    my $page = $q->param('action');
    $Pages{$page}->();
}
else  {
    noSuchPage();
}

    [download]
    When PerlJam sends an action parameter with the 'displayCards' value, he gets uninitialized value errors in the $Pages{$page} call.

    My solution would be to say: 

    my $action = $query->param('action');
if (exists $Pages{$action}) {
    $Pages{$action}->();
} else {
    noSuchPage();
}

    [download]
    This would reveal that there's no key in %Pages named 'displayCards'. Instead, it's 'View Flashcards'. :)
[reply]
[d/l]
[select]
      Thank you so much kind sir. I can't believe I didn't notice that :)
      ----
      Nothing in the world can take the place of persistence. Talent will not; nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated failures. Persistence and determination alone are omnipotent. --Calvin Coolidge (1872-1933)
[reply]

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