mb_strpos(): Offset not contained in string

Question

I found this function to create an excerpt for long text. I use this method to manage also accents like è é à ò ì ù ....

function excerpt($string, $lenght = 50, $popover = false, $ellipsed = false) {

    if ( $ellipsed ) {

      $ellipse = "...";

      if ( $popover )
        $ellipse = '<span title="More info" data-toggle="popover" data-trigger="hover" data-content="' . $string . '">...</span>';

    } else {
        $ellipse = "";
    }

    $boundaryPos = mb_strrpos(mb_substr($string, 0, mb_strpos($string, ' ', $lenght)), ' ');

    return mb_substr($string, 0, $boundaryPos === false ? $lenght : $boundaryPos) . $ellipse;

}

Some tests:

echo excerpt("Il treno è partito", 11);
//RETURN Il treno è

echo excerpt("Il treno è partito", 15);
//RETURN Il treno è part

echo excerpt("Il treno è partito", 20);
//RETURN WARNING mb_strpos(): Offset not contained in string

How can I fix error for the last test?

Answer 1

You need to check if the length of the string is less than your length parameter because you can't find 20-th offset of the string, which has length of 19.

P.S. You also have a typo in your length parameter of the excerpt function.

function excerpt($string, $length = 50, $popover = false, $ellipsed = false) {

    if ( $ellipsed ) {

      $ellipse = "...";

    if ( $popover )
        $ellipse = '<span title="More info" data-toggle="popover" data-trigger="hover" data-content="' . $string . '">...</span>';
    } else {
        $ellipse = "";
    }

    if ( strlen($string) < $length ) {
        return $string . $ellipse;
    }

    $boundaryPos = mb_strrpos(mb_substr($string, 0, mb_strpos($string, ' ', $length)), ' ');

    return mb_substr($string, 0, $boundaryPos === false ? $length : $boundaryPos) . $ellipse;

}

echo excerpt("Il treno è partito", 11);
echo excerpt("Il treno è partito", 20);