计算textarea中的行数，包括自动换行符

Question

I have a textarea

<textarea id="text" name="text" rows="6"></textarea>

<style>
    #text { width: 30%; }
</style>

When submitting the form, I need to check if the input exceeded 6 rows. I have a JS code, which checks for scrollbar (scrollbar present = more than 6 lines = invalid input) which works perfectly. The tricky part is, how can validate the input with PHP in case of disabled JS?

I tried something like this

public function overflowValidator($input, $maxLines, $cols) {
    $linebreakCount = substr_count($input, "
");
    $overflow1 = ($linebreakCount <= $maxLines);
    $overflow2 = (ceil(strlen($input) / $cols) <= $maxLines);
    return $overflow1 && $overflow2;
}

The biggest problem is that the width of the textarea is dynamic (responsive design) so I can't easily tell how many letters fit into one line. I'm afraid this can't be solved but maybe there is a solution I'm not aware of...

Answer 1

It might be a better idea to count the total amount of characters instead of lines but here is the code which allows you to do that :

    preg_match_all("/(
)/", $_POST['text'], $matches);
    $total_lines = count($matches[0]) + 1;