Ouzo\Utilities\Strings::isBlank PHP Method

    public static function isBlank($string)
    {
        return mb_strlen(trim($string)) == 0;
    }

 public function validateNotBlank($value, $errorMessage, $errorField = null)
 {
     if (Strings::isBlank($value)) {
         $this->error($errorMessage);
         $this->_errorFields[] = $errorField;
     }
 }