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Version: 1.7

Type Registration

This page covers registration APIs for user-defined types.

Why Registration Is Required​

Register user-defined structs, classes, enums, unions, and external targets before serialization or deserialization.

If a type is missing, deserialization fails with:

  • Type not registered: ...

Register by Numeric ID​

Use a stable ID shared by serializer and deserializer peers.

@ForyStruct
struct User {
    var name: String = ""
    var age: Int32 = 0
}

let fory = Fory()
try fory.register(User.self, id: 1)

For an external structural serializer, register the separate serializer declaration:

@ForyStruct(target: ThirdParty.User.self)
struct UserSerializer {
    var name: String
    var age: UInt32
}

try fory.register(UserSerializer.self, id: 1)

If an application intentionally gives an external type one retroactive Serializer conformance with Target == Self, register the target itself:

try fory.register(UUID.self, id: 2)

After registering a separate serializer, select it explicitly at each root, field, or carrier child where it is required.

Register by Name​

Fully-qualified name​

try fory.register(User.self, name: "com.example.User")

name is split by the last .:

  • namespace: com.example
  • type name: User

Simple names such as User use an empty namespace. Empty names and names ending in . are invalid.

Consistency Rules​

Keep registration mapping consistent across peers:

  • ID mode: same type uses same numeric ID on all peers
  • Name mode: same type uses same namespace and type name on all peers
  • Do not mix ID and name mapping for the same logical type across services
  • Register only one serializer for each target type on a Fory instance

Registration closes after the first root serialization or deserialization. Complete all registrations before the first root operation.

Dynamic Types and Registration​

When serializing Any, AnyObject, or application protocol values, register each concrete target through its ordinary, external structural, or custom serializer. Any and AnyObject use direct root APIs; application protocols select DynamicSerializer<T> explicitly.