如何使用带有括号的php preg_replace突出显示搜索关键字？

Question

I want to highlight my keyword search text by using preg_replace in php but the problem is it won't work with parentheses string ( and )

My function look like this...

$text_oritinal = "25 Hours: Colour In White (CD)";

function highlight($text_search, $text_original) {
  $str = preg_replace('#'. $text_search .'#i', '<span style="background-color:#FFFF66; color:#FF0000;">\\0</span>', $text_original);
  return $str;
}

Full original text is "25 Hours: Colour In White (CD)"

For example. If I use the keyword

$text_search = "25 Hours: Colour In White";

It return good replaced keyword with highlight background and text color.

<span style="background-color:#FFFF66; color:#FF0000;">25 Hours: Colour In White</span> (CD)

but! if I use this keyword included parentheses string ( and )

$text_search = "25 Hours: Colour In White (CD)";

It NOT return replaced background and text color.

I think it stuck with parentheses string ( and )

The question is how to highlight all text keyword matched without any problem with parentheses string ( and ) ?

Please share your idea. Thanks :)

Answer 1

You should call preg_quote :

function highlight($text_highlight, $text_search) {
  $str = preg_replace('#'. preg_quote($text_highlight) .'#i', '<span style="background-color:#FFFF66; color:#FF0000;">\\0</span>', $text_search);
  return $str;
}

Explanation:

Parenthesis are used to create submatches . Using them in your search string, will cause undesired results as they are reserved characters. You can prevent this, and other characters by using preg_quote which escapes regex reserved characters.

Answer 2

Wrap the text you put into the regex in preg_quote

http://php.net/manual/en/function.preg-quote.php