Symfony 4：从应用于集合类型的计数约束中获取错误消息

Question

I am using a collection type of symfony 4, and i wish to apply a count constraint to this collection.

I have followed this tutorial: https://symfony.com/doc/current/form/form_collections.html

My idea is to apply the constraint directly on the collection:

$builder
    ->add('tags', CollectionType::class, [
        'entry_type' => Tag::class,
        'entry_options' => ['label' => false],
        'allow_add' => true,
        'by_reference' => false,
        'constraints' => [
            new Assert\Count(['min' => 1, 'max' => 3])
        ]
    ])
;

But this does not work: I do not get any error message...

I have also try to use this constraint directly in the entity Task , without success.

So how can I get the error message from count constraint applied on collection type?

Answer 1

As @emix said in comment

With NotNull you tell the validator the field cannot be empty. Using the Count validator you limit the collection's size (using the min/max or both)

And to print the error I set the parameter error_bubbling to false of the CollectionType .

Answer 2

If you are using doctrine annotations, I think you can proceed like this:

Do not pass the constraint in the form builder. I would have added the constraint in the entity where you stored the tags.

Something like this

/**
 * @Assert\Count(
 *      min = 1,
 *      max = 5,
 *      minMessage = "You must specify at least one Tag",
 *      maxMessage = "You cannot specify more than 5 tags"
 * )
 */
 protected $tags;

If this isn't stored in any entity, you might want to handle the assertion by yourself in the controller dealing with your form action.