function preview($text)
// we don't want new lines in our preview
$text_only_spaces = preg_replace('/\s+/', ' ', $text);
// truncates the text
$text_truncated = mb_substr($text_only_spaces, 0, mb_strpos($text_only_spaces, " ", 50));
// prevents last word truncation
$preview = trim(mb_substr($text_truncated, 0, mb_strrpos($text_truncated, " ")));
$preview."...";
}