To follow up 1nickt's recommendation that you should use a templating system, consider:

use strict;
use warnings;
use HTML::Template;

my $app = sub {
    my $htmlFile = genHTML_File();
    my @options = map {{value => $_}} 'happy', 'sad', 'worrried';
    my $tplt = HTML::Template->new(filename => $htmlFile);
    
    $tplt->param(options => \@options);
    return [200, ['Content-Type' => 'text/html'], [$tplt->output()]];
};
print $app->()[2][0];


sub genHTML_File {
    my $filename = 'delme.html';
    
    open my $outHTML, '>', $filename or die "Can't create '$filename':
+ $!\n";
    print $outHTML <<HTML;
<html>
<head></head>
<body>
  <select><TMPL_LOOP name='options'>
    <option value='<TMPL_VAR name="value"/>'><TMPL_VAR name='value'/><
+/option></TMPL_LOOP>
  </select>
</body>
</html> 
HTML
    return $filename;
}

[download]

Prints:

<html>
<head></head>
<body>
  <select>
    <option value='happy'>happy</option>
    <option value='sad'>sad</option>
    <option value='worrried'>worrried</option>
  </select>
</body>
</html>

[download]

In real code genHTML_File doesn't exist. Instead you put the HTML into an external file.

Premature optimization is the root of all job security

In reply to Re: How do I run a loop within a PSGI application by GrandFather
in thread How do I run a loop within a PSGI application by tiny_monk

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