input input - 4 months ago 16
HTML Question

highlight multiple keywords in search

i'm using this code to highlight search keywords:

function highlightWords($string, $word)
{

$string = str_replace($word, "<span class='highlight'>".$word."</span>", $string);
/*** return the highlighted string ***/
return $string;

}

....

$cQuote = highlightWords(htmlspecialchars($row['cQuotes']), $search_result);


however, this highlights only one keyword. if the user enters more than one keyword, it will narrow down the search but no word is highlighted. how can i highlight more than one word?

Answer

regular expressions is the way to go!

function highlight($text, $words) {
    preg_match_all('~\w+~', $words, $m);
    if(!$m)
        return $text;
    $re = '~\\b(' . implode('|', $m[0]) . ')\\b~';
    return preg_replace($re, '<b>$0</b>', $text);
}

$text = '
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam,
quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
consequat.
';

$words = 'ipsum labore';

print highlight($text, $words);

To match in a case-insensitive manner, add 'i' to the regular expression

    $re = '~\\b(' . implode('|', $m[0]) . ')\\b~i';

NB: for non-enlish letters like "รค" the results may vary depending on the locale.

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