I’m using the following Perl code to traverse and format some HTML:
#!/usr/bin/env perl
use v5.38;
use HTML::TreeBuilder;
my $indent = 3;
my $content = do {local $/; <DATA>};
my $tree = HTML::TreeBuilder->new();
$tree->parse_content($content);
visit($tree);
sub visit($x) {
my $depth = $x->depth;
my $in = ' ' x ($indent * $depth);
foreach my $e ($x->content_list) {
# element
if (ref ($e)) {
say $in . $e->starttag;
visit($e);
say $in . $e->endtag;
}
# text
else {
say $in . $e;
}
}
}
__DATA__
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
</head>
<body>
<font size=3><strong>
5/5/61 Bob & Jerry - Arroyo Lounge, Stanford University, Palo Alto, CA
</strong></font>
<br>
<img src="poster.png" alt="poster/ad" title="poster/ad">
<i>(Robert Hunter and Jerry Garcia; source: McNally, Jackson research)</i>
<br><br>
<font size=3><strong>
5/26/61 Bob & Jerry - Barbara Meier's 16th birthday party, Menlo Park, CA
</strong></font>
<br>
Follow The Drinking Gourd, John Henry, Santy Anno*, Poor Paddy Works On The Railway
<br>
<i>(*included on
<a href="https://www.garciafamilyprovisions.com/product/JY148COMBO/before-the-dead-4cd-set?cp=640_62123_100764" target="_blank">Before The Dead
</a>;
<a href="https://gdsets.com/63posters/1961_05_26.jpg" target="_blank">birthday doodle for Barbara by Jerry
</a>;
<a href="https://gdsets.com/63posters/1961_05_26a.jpg" target="_blank">the master tape
</a>
)
</i>
<br><br>
My problem is that each <br> is output as:
<br />
</br>
Both <br /> and </br> cause new lines to be rendered. I was surprised that endtag generated anything at all in the case of tag br (and img).
I avoided using HTML::Tree::traverse because the doc discourages its use:
[I]f you want to recursively visit every node in the tree, it’s almost
always simpler to write a subroutine does just that, than it is to
bundle up the pre- and/or post-order code in callbacks for the
traverse method.
There are no examples given, so the above is what I cooked up.
Am I using starttag and endtag correctly? Should I detect when I’m displaying a tag that doesn’t take an end tag and avoid calling endtag? What’s the right/best/simplest way to traverse an HTML tree and prettify it?