Comment générer l'extrait comme ceux générés par Google avec PHP et MySQL?

$string1="Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book.";
function trimmer($updates,$wrds,$pos){
    if(strlen($updates)<=$wrds) {
        return $updates;
} else {
        $marker = strrpos(substr($updates,$pos,$wrds),' ');
        $string = substr(substr($updates,$pos,$wrds),0,$marker)."...";
        return $string;
    }
}

$pos = strpos($string1, "dummy");
echo trimmer($string1,100,$pos);

function excerpt($text, $phrase, $radius = 100, $ending = "...") {
    $phraseLen = strlen($phrase);
    if ($radius < $phraseLen) {
        $radius = $phraseLen;
    }

    $pos = strpos(strtolower($text), strtolower($phrase));

    $startPos = 0;
    if ($pos > $radius) {
        $startPos = $pos - $radius;
    }

    $textLen = strlen($text);

    $endPos = $pos + $phraseLen + $radius;
    if ($endPos >= $textLen) {
        $endPos = $textLen;
    }

    $excerpt = substr($text, $startPos, $endPos - $startPos);
    if ($startPos != 0) {
        $excerpt = substr_replace($excerpt, $ending, 0, $phraseLen);
    }

    if ($endPos != $textLen) {
        $excerpt = substr_replace($excerpt, $ending, -$phraseLen);
    }

    return $excerpt;
}
Shamelessly stolen from the Cake TextHelper.

La fonction de DÉCEZE modifiée légèrement pour permettre de multiples phrases. par exemple. Votre phrase peut être "TESTA TESTB" et s'il ne trouve pas TESTA, il ira à TestB.

function highlight($c,$q){ 
$q=explode(' ',str_replace(array('','\\','+','*','?','[','^',']','$','(',')','{','}','=','!','<','>','|',':','#','-','_'),'',$q));
for($i=0;$i<sizeOf($q);$i++) 
    $c=preg_replace("/($q[$i])(?![^<]*>)/i","<span class=\"highlight\">\${1}</span>",$c);
return $c;}