Making a form type with two separate values in it that you can add several times with symfony 4

Question

I'm new to Symfony and I want to do something using symfony 4. To simplify it, let's say for example I have a shopping basket where I can add or remove articles AND select the amount of each article I've chosen.

So on the doctrine side I have three entities :

class Basket {
   protected $id;
   protected $name;
}

class Article{
   protected $id;
   protected $name;
}

class Buying {
   //ManyToOne
   protected $basket;
   //ManyToOne
   protected $article;

   protected $count;
}

I've done this form by making the HTML by hand and using some nasty JS code, but now I'd like to make this using Symfony 4's Forms.

I thought the best way would be to create my own form type for that "Buying" entity which would have two fields, one of them being a Select containing every articles, and the other being the $count value, and then have the possibility to add as many "Buyings" as I want, but I can't think of a way to do this and the documentation don't seem to cover this kind of case.

Answer 1

You'd need a couple of form types for this and you may need to jiggle your entities a bit. Here's the gist of it:

First you need one for each individual item purchased and its count. The EntityType will give you a select with all your articles, exactly what you are looking for.

// BuyingType.php
$builder->add('article', EntityType::class, ['class' => Article::class]);
$builder->add('count', NumberType::class, [
    'constraints' => [
        new Count(['min' => 1]),
      ],
]);

The second one will be a CollectionType representing the whole basket.

// BasketType.php
$builder->add('basket', CollectionType::class, [
    'entry_type' => BuyingType::class,
    'allow_add' => true,
    'allow_delete' => true,
]);