Greetings.

Perhaps this is bug with HTML Tidy. One of my scripts was subjected to some HTML today which passed through HTML Tidy but nonetheless crashed HTML::TreeBuilder::XPath. Below is a stripped down sample. The following Perl script produces the error message "Can't locate object method "as_XML_indented" via package " trololo " (perhaps you forgot to load " trololo "?) at ./script.pl line 12." and does not proceed through the rest of the script. 

#!/usr/bin/perl

use HTML::TreeBuilder::XPath;
use strict;
use warnings;

my $tree = HTML::TreeBuilder::XPath->new_from_file(\*DATA);

for my $body ($tree->findnodes('//body')) {
    for my $element ($body->detach_content) {
        print $element->as_XML_indented;
    }
}

print "\n";
print "OK\n";

exit(0);

__DATA__
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <meta name="generator" content=
  "HTML Tidy for HTML5 for Linux version 5.6.0" />
  <title></title>
</head>
<body>
  <p>foo</p>
  <p>bar</p>
  trololo
</body>
</html>

[download]

Since the HTML seems to be valid, having just passed through HTML Tidy, I would have expected as_XML_indented to have just plowed through it, either rendering it as XML or at least not stopping. A work-around has been to wrap it in an eval, 

#!/usr/bin/perl

use HTML::TreeBuilder::XPath;
use strict;
use warnings;

my $tree = HTML::TreeBuilder::XPath->new_from_file(\*DATA);

for my $body ($tree->findnodes('//body')) {
    for my $element ($body->detach_content) {
    eval {
        print $element->as_XML_indented;
    };
    if ($@) {
        print STDERR qq(\n),$@,qq(\n);
        print STDERR qq(Failed HTML.\n);
    }
}

print "\n";
print "OK\n";

exit(0);

__DATA__
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
  <meta name="generator" content=
  "HTML Tidy for HTML5 for Linux version 5.6.0" />
  <title></title>
</head>
<body>
  <p>foo</p>
  <p>bar</p>
  trololo
</body>
</html>

[download]

I'm not sure how to interpret the HTML5 spec. However, the HTML4 spec seems to indicate that the loose text ought to have been wrapped in a block element of some kind.

So if I may tap your collective wisdom,

  1. Is this a bug with HTML::TreeBuilder::XPath or with HTML Tidy?
  2. For error trapping:
    1. Is there a better way to do eval?
    2. Or should try / catch be used?

General comments and advice also welcome.

In reply to Seemingly Valid HTML which crashes HTML::TreeBuilder::XPath by mldvx4

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