strip_html.filter

# Copyright 2009 Interchange Development Group and others
# 
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version. See the LICENSE file for details.

CodeDef strip_html Filter
CodeDef strip_html Description Strip HTML
CodeDef strip_html Routine <<EOR
sub {
    my $val = shift;

	# get rid of HTML comments
	$val =~ s/<!(?:--(?:[^-]*|-[^-]+)*--\s*)>//s;

    # replace these container tags with a space
    $val =~ s{</?(?:p|ol|ul|li|div|h[123456]|pre|dl|dd|dt|form|option|textarea|blockquote)(?:\s[^>]*)?>}{ }ig;

    # replace these self-closing tags with a space
    $val =~ s{<[bh]r(?:\s*/|\s[^>]*)?>}{ }ig;

    # remove all remaining tags and leave no space
    $val =~ s{</?\w[^>]*>}{}g;

    # collapse all whitespace, as HTML does when rendering anyway,
    # to facilitate truncating at a certain number of characters
    $val =~ s{\A\s+}{};
    $val =~ s{\s+\z}{};
    $val =~ s{\s+}{ }g;

    return $val;
}
EOR