There is an PHP function to HightLight a word in a string but not case sensitive/accent sensitive?

Question

There is a PHP function that can highlight a word regardless of case or accents, but the string returned will be the original string with only the highlighting? For example:

Function highlight($string, $term_to_search){
// ...
}
echo highlight("my Striñg", "string")
// Result: "my <b>Striñg</b>"

Thanks in advance!

What I tried:

I tried to do a function that removed all accents & caps, then did a "str_replace" with the search term but found that the end result logically had no caps or special characters when I expected it to be just normal text but highlighted.

Answer 1

You can use ICU library to normalize the strings. Then, look for term position inside handle string, to add HTML tags at the right place inside original string.

function highlight($string, $term_to_search, Transliterator $tlr) {
    $normalizedStr = $tlr->transliterate($string);
    $normalizedTerm = $tlr->transliterate($term_to_search);

    $termPos = mb_strpos($normalizedStr, $normalizedTerm);
    // Actually, `mb_` prefix is useless since strings are normalized

    if ($termPos === false) { //term not found
        return $string;
    }

    $termLength = mb_strlen($term_to_search);
    $termEndPos = $termPos + $termLength;
    
    return
        mb_substr($string, 0, $termPos)
        . '<b>'
        . mb_substr($string, $termPos, $termLength)
        . '</b>'
        . mb_substr($string, $termEndPos);
}

$tlr = Transliterator::create('Any-Latin; Latin-ASCII; Lower();');

echo highlight('Would you like a café, Mister Kàpêk?', 'kaPÉ', $tlr);