Participant attributes

Sources/LiveKit/Core/SignalClient.swift

@@ -495,11 +495,15 @@ extension SignalClient {
         try await _sendRequest(r)
     }
 
-    func sendUpdateParticipant(metadata: String? = nil, name: String? = nil) async throws {
+    func sendUpdateParticipant(name: String? = nil,
+                               metadata: String? = nil,
+                               attributes: [String: String]? = nil) async throws
+    {
         let r = Livekit_SignalRequest.with {
             $0.updateMetadata = Livekit_UpdateParticipantMetadata.with {
-                $0.metadata = metadata ?? ""
                 $0.name = name ?? ""
+                $0.metadata = metadata ?? ""
+                $0.attributes = attributes ?? [:]
             }
         }
 

Sources/LiveKit/Participant/LocalParticipant.swift

@@ -189,6 +189,12 @@ public class LocalParticipant: Participant {
         _state.mutate { $0.name = name }
     }
 
+    public func set(attributes: [String: String]) async throws {
+        let room = try requireRoom()
+        try await room.signalClient.sendUpdateParticipant(attributes: attributes)
+        _state.mutate { $0.attributes = attributes }
+    }
+
     func sendTrackSubscriptionPermissions() async throws {
         let room = try requireRoom()
         guard room._state.connectionState == .connected else { return }

Sources/LiveKit/Participant/Participant.swift

@@ -46,6 +46,9 @@ public class Participant: NSObject, ObservableObject, Loggable {
     @objc
     public var metadata: String? { _state.metadata }
 
+    @objc
+    public var attributes: [String: String] { _state.attributes }
+
     @objc
     public var connectionQuality: ConnectionQuality { _state.connectionQuality }
 
@@ -91,6 +94,7 @@ public class Participant: NSObject, ObservableObject, Loggable {
         var connectionQuality: ConnectionQuality = .unknown
         var permissions = ParticipantPermissions()
         var trackPublications = [Track.Sid: TrackPublication]()
+        var attributes = [String: String]()
     }
 
     let _state: StateSync<State>
@@ -141,6 +145,22 @@ public class Participant: NSObject, ObservableObject, Loggable {
                 }
             }
 
+            // attributes updated
+            if newState.attributes != oldState.attributes {
+                // Compute diff of attributes
+                let attributesDiff = computeAttributesDiff(oldValues: oldState.attributes, newValues: newState.attributes)
+                if !attributesDiff.isEmpty {
+                    // Notfy ParticipantDelegate
+                    self.delegates.notify(label: { "participant.didUpdateAttributes: \(String(describing: attributesDiff))" }) {
+                        $0.participant?(self, didUpdateAttributes: attributesDiff)
+                    }
+                    // Notify RoomDelegate
+                    room.delegates.notify(label: { "room.didUpdateAttributes: \(String(describing: attributesDiff))" }) {
+                        $0.room?(room, participant: self, didUpdateAttributes: attributesDiff)
+                    }
+                }
+            }
+
             if newState.connectionQuality != oldState.connectionQuality {
                 self.delegates.notify(label: { "participant.didUpdate connectionQuality: \(self.connectionQuality)" }) {
                     $0.participant?(self, didUpdateConnectionQuality: self.connectionQuality)
@@ -193,6 +213,7 @@ public class Participant: NSObject, ObservableObject, Loggable {
             $0.metadata = info.metadata
             $0.joinedAt = Date(timeIntervalSince1970: TimeInterval(info.joinedAt))
             $0.kind = info.kind.toLKType()
+            $0.attributes = info.attributes
         }
 
         self.info = info

Sources/LiveKit/Protocols/ParticipantDelegate.swift

@@ -51,6 +51,9 @@ public protocol ParticipantDelegate: AnyObject {
     @objc optional
     func participant(_ participant: Participant, didUpdatePermissions permissions: ParticipantPermissions)
 
+    @objc optional
+    func participant(_ participant: Participant, didUpdateAttributes attributes: [String: String])
+
     // MARK: - TrackPublication
 
     /// `muted` state has updated for the ``Participant``'s ``TrackPublication``.

Sources/LiveKit/Protocols/RoomDelegate.swift

@@ -99,6 +99,9 @@ public protocol RoomDelegate: AnyObject {
     @objc optional
     func room(_ room: Room, participant: Participant, didUpdatePermissions permissions: ParticipantPermissions)
 
+    @objc optional
+    func room(_ room: Room, participant: Participant, didUpdateAttributes attributes: [String: String])
+
     // MARK: - Track Publications
 
     /// The ``LocalParticipant`` has published a ``LocalTrack``.

Sources/LiveKit/Support/Utils.swift

@@ -263,3 +263,16 @@ extension MutableCollection {
         }
     }
 }
+
+func computeAttributesDiff(oldValues: [String: String], newValues: [String: String]) -> [String: String] {
+    var allKeys = Set(oldValues.keys).union(newValues.keys)
+    var diff = [String: String]()
+
+    for key in allKeys {
+        if oldValues[key] != newValues[key] {
+            diff[key] = newValues[key] ?? ""
+        }
+    }
+
+    return diff
+}

Tests/LiveKitTests/FunctionTests.swift

@@ -26,4 +26,31 @@ class FunctionTests: XCTestCase {
         print("merged: \(merged)")
         XCTAssert(merged == 5 ... 20)
     }
+
+    func testAttributesUpdated() {
+        let oldValues: [String: String] = ["a": "value", "b": "initial", "c": "value"]
+        let newValues: [String: String] = ["a": "value", "b": "updated", "c": "value"]
+
+        let diff = computeAttributesDiff(oldValues: oldValues, newValues: newValues)
+        XCTAssertEqual(diff.count, 1)
+        XCTAssertEqual(diff["b"], "updated")
+    }
+
+    func testAttributesNew() {
+        let newValues: [String: String] = ["a": "value", "b": "value", "c": "value"]
+        let oldValues: [String: String] = ["a": "value", "b": "value"]
+
+        let diff = computeAttributesDiff(oldValues: oldValues, newValues: newValues)
+        XCTAssertEqual(diff.count, 1)
+        XCTAssertEqual(diff["c"], "value")
+    }
+
+    func testAttributesRemoved() {
+        let newValues: [String: String] = ["a": "value", "b": "value"]
+        let oldValues: [String: String] = ["a": "value", "b": "value", "c": "value"]
+
+        let diff = computeAttributesDiff(oldValues: oldValues, newValues: newValues)
+        XCTAssertEqual(diff.count, 1)
+        XCTAssertEqual(diff["c"], "")
+    }
 }