Forms and validation

The accepted services

A field and a constraint name the services they accept as phil/url-bundle names kinds of address: null for every international service, an enum class for all its cases, a case, an EnumSet, or a list of these; cases of one enum make one set, sets keep the order they first appear in.

HandleType

Two fields, to and from a Handle: the service, chosen among the accepted ones — the choices in that order, named by label() for the international services and by their case's name for the application's —, and the handle as the person types it.

$builder->add('messenger', HandleType::class, ['types' => [ForumMessenger::class, KnownMessenger::Signal], 'required' => false]);

An empty handle is null; a handle the chosen service does not read makes the field invalid with This value is not a valid handle on this service. A handle is shown as people read it, @adalove, when its service reads that text back to the same handle, and in its canonical form otherwise: an edit form submitted unchanged keeps its handle, even for an application's service whose display() decorates it.

HandleOfType

#[HandleOfType([KnownMessenger::Signal, KnownMessenger::WhatsApp])]
public ?Handle $messenger = null;

A Handle is checked by its service; a text by detection among the accepted services. null and the empty text are valid. The message, This handle is on none of the accepted services: {{ types }}., has the code HandleOfType::NOT_ACCEPTED_ERROR.

Storing a handle

A handle is two columns the application maps, the service with its own enum:

#[ORM\Column(enumType: KnownMessenger::class)]
private KnownMessenger $service;

#[ORM\Column(length: 255)]
private string $handle;

public function messenger(): Handle
{
    return Handle::fromCanonical($this->service, $this->handle);
}

public function setMessenger(Handle $messenger): void
{
    [$this->service, $this->handle] = [$messenger->type, $messenger->value];
}

The handle stored is the canonical one, read when it was kept. Handle::fromCanonical() takes it back as it is: Handle::of() would read it again, and refuse a phone number that a later import of the numbering plans no longer knows, so that the entity could no longer be loaded or shown.