Long story. My team has a group of custom libraries for inserting values into an HTML template within perl. Problem is these libraries were written way back when perl4 was da bomb.

When I try and use the -w option in a cgi that uses these libraries, I run into all sorts of problems. So I went looking for CPAN modules that I could replace bits of our library with. For this particular thing, the Template Toolkit seems to perform quite well, with one exception:

The old libraries could populate template variables with the output of functions which were run when the template parser reached the variable.

So far, I have no problem with setting up the perl Template object and changing tags to fit the old html templates and doing simple replacements, but when I try and use a function, the function runs at the very beginning of the script and I see the output at the top of the page instead of at the proper point in the template. I've included a small example below:

First the template file: 

<html>
<head><title>{#page_title#}</title></head>
<body>
Here's a list of {#elements#} numbers:<br>
<ul>
{#show_elements#}
</ul>
</body>
</html>

[download]

And the corresponding cgi: 

#!/usr/bin/perl -w

use strict;
use CGI qw/:standard/;
use Template;

sub show_elements ($)
{
    my $num = $_[0];
    return unless( $num > 0 );
    print qq(<li>$_</li>\n) for( 1 .. $num );

    '';
}

my $elements = 6;

my $cgi = CGI->new;
my $tt = Template->new( {
    START_TAG => quotemeta( '{#' ),
    END_TAG =>   quotemeta( '#}' ),
} );

my $data = { page_title => 'Elbie Intl Numbers Inc.',
             elements   => $elements,
             show_elements => \&show_elements( $elements ),
             };

print $cgi->header();
$tt->process( 'test.html', $data ) || die $tt->error;

[download]

So what I get is an enumerated list above the HTML headers, and SCALAR(0x82921d4) or similar where the list should go.

Granted, given enough time, I would just rewrite all the called subroutines, but for now I just need to drop something in place of my existing template functions.

Any help would be greatly appreciated.

elbieelbieelbie

In reply to Template Toolkit, and delaying the execution of a function by elbie

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