attach method
Attaches the portal within host
.
Returns a future that completes with an instance of the portal's instance.
Throws StateError if a portal is already attached.
Implementation
Future<dynamic /*ComponentRef<Object> | Map<String, dynamic>*/ > attach(
PortalHost? host) {
assert(host != null);
if (isAttached) {
throw StateError('Already attached to host!');
} else {
_attachedHost = host;
return host?.attach(this) as Future<T>;
}
}