in reply to How to get unselected radio_group() items after submitting form

The most likely culprit if your problem is the end_form function as demonstrated below.

I created the following cgi script to test your issue

#!/usr/bin/perl -wT

use CGI;
use CGI::Carp qw(fatalsToBrowser warningsToBrowser);

use strict;
use warnings;

my $q = CGI->new;

print $q->header();
print <<"END_HTML";
<html>
<body>
<form method="post">
END_HTML

foreach my $f (qw(foo bar baz)) {
    print "<p>$f</p>\n";
    print $q->radio_group(
        -name    => $f,
        -values  => [qw(c r t s)],
        -default => '-',
    ) . "\n";
}

print $q->submit(-name => 'submit', -value => 'save') . "\n";

print <<"END_HTML";
</form>
</body>
</html>
END_HTML

1;

__END__

[download]

This appears to work as you desire. You can hit submit multiple times, and it will only autofill the radio buttons that were previously selected by the user.

However, if I replace my hardcoded form tags with the cgi functions start_form and end_form, then your problem appears.

#!/usr/bin/perl -wT

use CGI;
use CGI::Carp qw(fatalsToBrowser warningsToBrowser);

use strict;
use warnings;

my $q = CGI->new;

print $q->header();
print <<"END_HTML";
<html>
<body>
END_HTML

print $q->start_form() . "\n"; # <------ Changed code

foreach my $f (qw(foo bar baz)) {
    print "<p>$f</p>\n";
    print $q->radio_group(
        -name    => $f,
        -values  => [qw(c r t s)],
        -default => '-',
    ) . "\n";
}

print $q->submit(-name => 'submit', -value => 'save') . "\n";

print $q->end_form() . "\n"; # <------ Changed code

print <<"END_HTML";
</body>
</html>
END_HTML

1;

__END__

[download]

I therefore suggest that you start your investigation there. At the very least you can hardcode your form tags and avoid the problem, but it appears the end_form function adds the following text that for some reason creates your issue.

<div><input type="hidden" name=".cgifields" value="bar"  /><input type
+="hidden"
name=".cgifields" value="baz"  /><input type="hidden" name=".cgifields
+" value="f
oo"  /></div>

[download]
- Miller

Replies are listed 'Best First'.
Re^2: How to get unselected radio_group() items after submitting form
by slugger415 (Monk) on Mar 08, 2011 at 21:50 UTC
    Interesting! Yes, Miller, that worked, much as I hate hard coding... :-)

    Thanks also to Wallisds for a more official solution.

    Scott
[reply]

      If you look at the source code of CGI, you can discover the code inside end_form that is adding all the extra hidden variables.

      sub end_form {
    my($self,@p) = self_or_default(@_);
    if ( $NOSTICKY ) {
        return wantarray ? ("</form>") : "\n</form>";
    } else {
        if (my @fields = $self->get_fields) {
            return wantarray ? ("<div>",@fields,"</div>","</form>")
                             : "<div>".(join '',@fields)."</div>\n</fo
+rm>";
        } else {
            return "</form>";
        }
    }
}

      [download]

      As you can see above, the $NOSTICKY global will prevent the extra hidden fields that lead to the undesired default values. After reading the documentation of $NOSTICKY, you can set this in two different ways. One of them is more global:

      use CGI qw(-nosticky);

      [download]

      Or you can is isolate the change to just the end_form function by doing the following:

      print do {local $CGI::NOSTICKY = 1; $q->end_form()} . "\n";

      [download]

      Or you can just simplify the whole process for yourself by writing a simple </form> tag. Really don't know why someone wouldn't just do that anyway as the CGI module really does try to do too much in my opinion.

      - Miller
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