Gregwar\Formidable\Form::addConstraint PHP Méthode

    public function addConstraint($name, $closure = null)
    {
        if ($name instanceof \Closure) {
            $closure = $name;
            $name = null;
        }
        if ($name == null) {
            $this->constraints[] = $closure;
        } else {
            $this->getField($name)->addConstraint($closure);
        }
    }