How to modify a form on Symfony

Question

so I'm creating an e-commerce website using symfony and twig. Right now The client can enter manually the quantity he wants of a specific product, but i want that quantity to not exceed the stock we have of that product. So for example if we have 5 chairs, i want him to choose between 1 and 5. For that i created a dropdown :

<div class="field select-box">
    <select name="quantity" data-placeholder="Select your quantity">

        {% for i in 1..produit.stock %}
        <option value="{{ i }}">{{ i }}</option>

        {% endfor %}
    </select>
</div>

I want to use the selected value to put it inside a form,, or maybe find another way to set the quantity asked without using the form or even just change the way the form looks because right now it only takes input. Should i generate another form ?

Hopefully i was clear.

Here's what my formType looks like :

class ContenuPanierType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options): void
    {
        $builder->add('quantite');

     
    }

    public function configureOptions(OptionsResolver $resolver): void
    {
        $resolver->setDefaults([
            'data_class' => ContenuPanier::class,
        ]);
    }
}

and here's a bit of code from the controller that creates a cart, add the products and all the information regarding it (quantity, user it belongs to, date)

 if(is_null($updateContenuPanier)) {
            $contenuPanier = new ContenuPanier();
            $contenuPanier->setDate(new Datetime());
            $contenuPanier->setPanier($panier);
            $contenuPanier->setProduit($produit);
            $contenuPanier->setQuantite($request->get("contenu_panier")["quantite"]);
        }

Answer 1

This can be done with the ChoiceType. You just need to determine your maximum allowed value and configure the appropriate options.

  public function buildForm(FormBuilderInterface $builder, array $options): void
  {
    // access the entity
    $entity = $builder->getData();

    // your custom logic to determine the maximum allowed integer value based on $entity
    $max = $entity->getStockOnHandMethodName();

    $builder->add('quantite', ChoiceType::class, [
      'choices'      => range(1, $max),
      'choice_label' => function ($choice) {
        // use the value for the label text
        return $choice;
      },
      // prevent empty placeholder option
      'placeholder'  => false,
    ]);
  }

I'm almost certain you will still need to verify that the submitted quantity is still valid in your controller action which handles the form submission.