Live Collection Type (Embedded CollectionType Form) & VICH Upload Files?

[woweya]

Hello — I'm working with Symfony 7.2, PHP 8.2, Symfony UX LiveComponent and VichUploader, and I have a reproducible problem when saving collection items that contain only a file field.

Environment

• Symfony 7.2
• PHP 8.2
• Symfony UX LiveComponent (LiveCollectionType Form)
• VichUploaderBundle for file handling

What I built

I have a form that renders a LiveCollectionType. Each collection item form contains two fields:

• file (VichFileType / input file)
• note (text)

In the browser I can:

1. Add a new collection item row.
2. Upload a file into that new row (leave note empty).
3. Click Save.

Observed behavior

When I save a newly added collection item that contains only a file (no note), the collection item is not created/persisted.

When I add a note together with the file (i.e. both file and note present), the item is correctly created and persists as expected.

When I debug in the LiveAction save method:

• The uploaded file is present in the Request ($request->files->all()).
• $this->form()->getData() shows myEntity => [ 'collection' => [ 0 ] ] . So the new collection item is empty / not formed.
• $this->formValues shows the new item as empty strings for file and note:

formValues => [
  'myEntity' => [
       [0] => [ 
         'file' => '',
         'note' => '',
     ]
  ]
]

My conclusion: LiveComponent formValues do not contain UploadedFile instances; files arrive via the HTTP Request and are not automatically merged into $this->formValues used by submitForm().

What I tried

Before calling $this->submitForm() I manually merged the Request files into $this->formValues, e.g.:

#[LiveAction]
public function save(Request $request): true
{
    try {
        $files = $request->files->all() ?? [];
        if (array_key_exists('my_type_form', $files)) {
            foreach ($files['my_type_form']['my_entity_field'] ?? [] as $key => $additionalDoc) {
                $uploadedFile = $additionalDoc['file']['file'] ?? null;
                $this->formValues['additionalCourseDocuments'][$key]['file'] = $uploadedFile;
            }
        }

        $this->submitForm();

        // ...other code...
    } catch ( ...) {
        // ...
    }
}

But at submit I get a validation error (even though there are no constraints on the file type). Digging deeper, it appears $this->submitForm() or the LiveComponent internals strip out or overwrite the modified values I inserted into $this->formValues and the file field becomes null again.

Workaround I considered

Count incoming files vs items in $this->formValues. If there are more form values than uploaded files, assume some items were added without documents and ignore those items. If counts match, process and persist. This works but feels brittle and hacky.

What I want to know

1. What is the correct pattern / best practice to handle file uploads inside a LiveCollectionType with Symfony UX LiveComponent?
2. How can I reliably ensure that a new collection item that contains only a file (no other text field) is accepted and created, without resorting to counting files vs. collection rows?
3. If manual merging of $request->files into $this->formValues is the right approach, what is the correct way to do it so LiveComponent / submitForm() will accept the UploadedFile instances and not overwrite/remove them?

Code snippets (for clarity)

FormType (simplified):

$builder->add('additionalCourseDocuments', LiveCollectionType::class, [
    'entry_type' => AdditionalCourseDocumentType::class,
    'allow_add' => true,
    'allow_delete' => true,
    'required' => false,
    'by_reference' => false,
]);

Entry Type (simplified):

$builder
    ->add('file', VichFileType::class, [
        'required' => false,
        'allow_delete' => false,
        'download_uri' => false,
    ])
    ->add('note', TextType::class, [
        'required' => false,
    ]);

If someone has solved this properly, know that you would be extremely helpful.
Thanks.