/**
* get the diff as a single text string
*
* @param string original content
* @param string updated content
* @return an ASCII string
*/
public static function &sdiff(&$original, &$updated)
{
global $context;
// compare the two sequences
$sequence = Scripts::compare($original, $updated, 2000);
// format the output string
$text = '';
foreach ($sequence as $item) {
list($tag, $left, $right) = $item;
//comment out suppressed lines
if ($tag == '-') {
if (strncmp($left, '<', 1)) {
$text .= ' <del>' . $left . '</del> ';
}
} elseif ($tag == '+') {
if (strncmp($right, '<', 1)) {
$text .= ' <ins>' . $right . '</ins> ';
} else {
$text .= $right . ' ';
}
} elseif ($right) {
if ($right[0] != '<' && $text && $text[strlen($text) - 1] != '>') {
$text .= ' ';
}
$text .= $right;
}
}
// recombine added words
$text = trim(str_replace(array('</del> <del>', '</ins> <ins>'), ' ', $text));
// return the result of the whole comparison
return $text;
}
