added examples for RoomCallback usage (#599)

also changed:
- moved data defs to data.go
- added a few additional DisconnectReason

Author: davidzhao

callback.go

@@ -125,20 +125,34 @@ func (cb *ParticipantCallback) Merge(other *ParticipantCallback) {
 type DisconnectionReason string
 
 const (
-	LeaveRequested  DisconnectionReason = "leave requested by room"
-	UserUnavailable DisconnectionReason = "remote user unavailable"
-	RejectedByUser  DisconnectionReason = "rejected by remote user"
-	Failed          DisconnectionReason = "connection to room failed"
+	LeaveRequested     DisconnectionReason = "leave requested by user"
+	UserUnavailable    DisconnectionReason = "remote user unavailable"
+	RejectedByUser     DisconnectionReason = "rejected by remote user"
+	Failed             DisconnectionReason = "connection to room failed"
+	RoomClosed         DisconnectionReason = "room closed"
+	ParticipantRemoved DisconnectionReason = "removed by server"
+	DuplicateIdentity  DisconnectionReason = "duplicate identity"
+	OtherReason        DisconnectionReason = "other reasons"
 )
 
 func GetDisconnectionReason(reason livekit.DisconnectReason) DisconnectionReason {
 	// TODO: SDK should forward the original reason and provide helpers like IsRequestedLeave.
-	r := LeaveRequested
+	r := OtherReason
 	switch reason {
+	case livekit.DisconnectReason_CLIENT_INITIATED:
+		r = LeaveRequested
 	case livekit.DisconnectReason_USER_UNAVAILABLE:
 		r = UserUnavailable
 	case livekit.DisconnectReason_USER_REJECTED:
 		r = RejectedByUser
+	case livekit.DisconnectReason_ROOM_CLOSED:
+		r = RoomClosed
+	case livekit.DisconnectReason_PARTICIPANT_REMOVED:
+		r = ParticipantRemoved
+	case livekit.DisconnectReason_DUPLICATE_IDENTITY:
+		r = DuplicateIdentity
+	case livekit.DisconnectReason_JOIN_FAILURE, livekit.DisconnectReason_SIGNAL_CLOSE, livekit.DisconnectReason_STATE_MISMATCH:
+		r = Failed
 	}
 	return r
 }

callback_test.go

@@ -0,0 +1,39 @@
+package lksdk_test
+
+import (
+	"fmt"
+
+	"github.com/livekit/protocol/livekit"
+	lksdk "github.com/livekit/server-sdk-go/v2"
+)
+
+// ExampleRoomCallback demonstrates usage of RoomCallback to handle various room events
+func ExampleRoomCallback() {
+	// Create a new callback handler
+	cb := lksdk.NewRoomCallback()
+
+	// Handle data packets received from other participants
+	cb.OnDataPacket = func(data lksdk.DataPacket, params lksdk.DataReceiveParams) {
+		// handle DTMF
+		switch val := data.(type) {
+		case *livekit.SipDTMF:
+			fmt.Printf("Received DTMF from %s: %s (%d)\n", params.SenderIdentity, val.Digit, val.Code)
+		case *lksdk.UserDataPacket:
+			fmt.Printf("Received user data from %s: %s\n", params.SenderIdentity, string(val.Payload))
+		}
+	}
+
+	// Handle participant metadata changes
+	cb.OnAttributesChanged = func(changed map[string]string, p lksdk.Participant) {
+		fmt.Printf("Participant %s attributes changed: %v\n", p.Identity(), changed)
+	}
+
+	// Handle when current participant becomes disconnected
+	cb.OnDisconnectedWithReason = func(reason lksdk.DisconnectionReason) {
+		fmt.Printf("Disconnected from room: %s\n", reason)
+	}
+
+	// Create a new room with the callback
+	room := lksdk.NewRoom(cb)
+	room.JoinWithToken("wss://myproject.livekit.cloud", "my-token")
+}

data.go

@@ -1,17 +1,63 @@
 package lksdk
 
-type dataPublishOptions struct {
-	Reliable              *bool
-	DestinationIdentities []string
-	Topic                 string
+import (
+	"github.com/livekit/protocol/livekit"
+	"google.golang.org/protobuf/proto"
+)
+
+// Data types
+
+type DataPacket interface {
+	ToProto() *livekit.DataPacket
+}
+
+// Compile-time assertion for all supported data packet types.
+var (
+	_ DataPacket = (*UserDataPacket)(nil)
+	_ DataPacket = (*livekit.SipDTMF)(nil) // implemented in the protocol package
+)
+
+// UserData is a custom user data that can be sent via WebRTC.
+func UserData(data []byte) *UserDataPacket {
+	return &UserDataPacket{Payload: data}
+}
+
+// UserDataPacket is a custom user data that can be sent via WebRTC on a custom topic.
+type UserDataPacket struct {
+	Payload []byte
+	Topic   string // optional
 }
 
+// ToProto implements DataPacket.
+func (p *UserDataPacket) ToProto() *livekit.DataPacket {
+	var topic *string
+	if p.Topic != "" {
+		topic = proto.String(p.Topic)
+	}
+	return &livekit.DataPacket{Value: &livekit.DataPacket_User{
+		User: &livekit.UserPacket{
+			Payload: p.Payload,
+			Topic:   topic,
+		},
+	}}
+}
+
+// receiving
+
 type DataReceiveParams struct {
 	Sender         *RemoteParticipant
 	SenderIdentity string
 	Topic          string // Deprecated: Use UserDataPacket.Topic
 }
 
+// publishing
+
+type dataPublishOptions struct {
+	Reliable              *bool
+	DestinationIdentities []string
+	Topic                 string
+}
+
 type DataPublishOption func(*dataPublishOptions)
 
 func WithDataPublishTopic(topic string) DataPublishOption {

localparticipant.go

@@ -342,41 +342,6 @@ func (p *LocalParticipant) PublishData(payload []byte, opts ...DataPublishOption
 	return p.PublishDataPacket(UserData(payload), opts...)
 }
 
-type DataPacket interface {
-	ToProto() *livekit.DataPacket
-}
-
-// Compile-time assertion for all supported data packet types.
-var (
-	_ DataPacket = (*UserDataPacket)(nil)
-	_ DataPacket = (*livekit.SipDTMF)(nil) // implemented in the protocol package
-)
-
-// UserData is a custom user data that can be sent via WebRTC.
-func UserData(data []byte) *UserDataPacket {
-	return &UserDataPacket{Payload: data}
-}
-
-// UserDataPacket is a custom user data that can be sent via WebRTC on a custom topic.
-type UserDataPacket struct {
-	Payload []byte
-	Topic   string // optional
-}
-
-// ToProto implements DataPacket.
-func (p *UserDataPacket) ToProto() *livekit.DataPacket {
-	var topic *string
-	if p.Topic != "" {
-		topic = proto.String(p.Topic)
-	}
-	return &livekit.DataPacket{Value: &livekit.DataPacket_User{
-		User: &livekit.UserPacket{
-			Payload: p.Payload,
-			Topic:   topic,
-		},
-	}}
-}
-
 // PublishDataPacket sends a packet via a WebRTC data channel. UserData can be used for sending custom user data.
 //
 // By default, the message can be received by all participants in a room,