sub pretty{
$_ = shift;
# Put a newline before every ‘open’ tag.
s”(<[^/])"\n$1"g;
# Eliminate duplicate newline.
s"[\n]{2,}(\n])\n</"$1</"g;
# Now we have lines the way we like them.
# It remains only to calculate indentations.
my @lines = split('\n',$_);
my $depth = -1;
foreach my $line (@lines){
# If line starts with an open tag, increase depth.
$depth+=1 if $line=~'^)|(</)';
}
$_ = join "\n", @lines;
$_ = $_ . "\n";
$_
}

pretty("text“)

… gives …

text

It looks like that snippet is quite widely used – it is the same one as at http://blog.bookworm.at/2007/03/pretty-print-xml-with-emacs.html.

I tested it and I do prefer the indentation slightly over (sgml-pretty-print …) but I still need join-broken-lines for when my cut and paste breaks a tag in the middle. E.g.

<ab
cd>
….
</abcd>

(defun indent-xml-region (begin end)
“Pretty format XML markup in region. You need to have nxml-mode
http://www.emacswiki.org/cgi-bin/wiki/NxmlMode installed to do
this. The function inserts linebreaks to separate tags that have
nothing but whitespace between them. It then indents the markup
by using nxml’s indentation rules.”
(interactive “r”)
(save-excursion
(nxml-mode)
(goto-char begin)
(while (search-forward-regexp “\>[ \\t]*\<” nil t)
(backward-char) (insert “\n”)
)
(mark-whole-buffer)
(indent-region begin end)
;(indent-region point-min point-max)
)
(message “Ah, much better!”))

Yes, I did see that article when I searching for similar posts. I think (bf-pretty-print-xml-region …) has an equivalent in sgml mode now – (sgml-pretty-print …)