feat: Enhancements to Plugin interface (#218)

Sources/Amplitude/Amplitude.swift

@@ -67,6 +67,11 @@ public class Amplitude {
         _ = add(plugin: AnalyticsConnectorPlugin())
         _ = add(plugin: AnalyticsConnectorIdentityPlugin())
         _ = add(plugin: AmplitudeDestinationPlugin())
+
+        // Monitor changes to optOut to send to Timeline
+        configuration.optOutChanged = { [weak self] optOut in
+            self?.timeline.onOptOutChanged(optOut)
+        }
     }
 
     convenience init(apiKey: String, configuration: Configuration) {
@@ -262,13 +267,15 @@ public class Amplitude {
     public func setUserId(userId: String?) -> Amplitude {
         try? storage.write(key: .USER_ID, value: userId)
         state.userId = userId
+        timeline.onUserIdChanged(userId)
         return self
     }
 
     @discardableResult
     public func setDeviceId(deviceId: String?) -> Amplitude {
         try? storage.write(key: .DEVICE_ID, value: deviceId)
         state.deviceId = deviceId
+        timeline.onDeviceIdChanged(deviceId)
         return self
     }
 
@@ -293,6 +300,7 @@ public class Amplitude {
             } else {
                 sessionEvents = self.sessions.endCurrentSession()
             }
+            self.timeline.onSessionIdChanged(sessionId)
             self.sessions.assignEventId(events: sessionEvents).forEach { e in
                 self.timeline.processEvent(event: e)
             }

Sources/Amplitude/Configuration.swift

@@ -12,7 +12,11 @@ public class Configuration {
     public var flushQueueSize: Int
     public var flushIntervalMillis: Int
     public internal(set) var instanceName: String
-    public var optOut: Bool
+    public var optOut: Bool {
+        didSet {
+            optOutChanged?(optOut)
+        }
+    }
     public let storageProvider: any Storage
     public let identifyStorageProvider: any Storage
     public var logLevel: LogLevelEnum
@@ -44,6 +48,7 @@ public class Configuration {
     public internal(set) var autocapture: AutocaptureOptions
     public var offline: Bool?
     internal let diagonostics: Diagnostics
+    var optOutChanged: ((Bool) -> Void)?
 
     @available(*, deprecated, message: "Please use the `autocapture` parameter instead.")
     public convenience init(

Sources/Amplitude/Plugins/BasePlugins.swift

@@ -17,6 +17,11 @@ open class BasePlugin {
     public func teardown(){
         // Clean up any resources from setup if necessary
     }
+
+    open func onUserIdChanged(_ userId: String?) {}
+    open func onDeviceIdChanged(_ deviceId: String?) {}
+    open func onSessionIdChanged(_ sessionId: Int64) {}
+    open func onOptOutChanged(_ optOut: Bool) {}
 }
 
 open class BeforePlugin: BasePlugin, Plugin {
@@ -33,7 +38,4 @@ open class UtilityPlugin: BasePlugin, Plugin {
 
 open class ObservePlugin: BasePlugin, Plugin {
     public let type: PluginType = .observe
-
-    open func onUserIdChanged(_ userId: String?) {}
-    open func onDeviceIdChanged(_ deviceId: String?) {}
 }

Sources/Amplitude/Timeline.swift

@@ -47,13 +47,6 @@ public class Timeline {
         }
     }
 
-    internal func applyClosure(_ closure: (Plugin) -> Void) {
-        for plugin in plugins {
-            let mediator = plugin.value
-            mediator.applyClosure(closure)
-        }
-    }
-
     internal func apply(_ closure: (Plugin) -> Void) {
         for type in PluginType.allCases {
             if let mediator = plugins[type] {
@@ -66,4 +59,20 @@ public class Timeline {
             }
         }
     }
+
+    func onUserIdChanged(_ userId: String?) {
+        apply { $0.onUserIdChanged(userId) }
+    }
+
+    func onDeviceIdChanged(_ deviceId: String?) {
+        apply { $0.onDeviceIdChanged(deviceId) }
+    }
+
+    func onSessionIdChanged(_ sessionId: Int64) {
+        apply { $0.onSessionIdChanged(sessionId) }
+    }
+
+    func onOptOutChanged(_ optOut: Bool) {
+        apply { $0.onOptOutChanged(optOut) }
+    }
 }

Sources/Amplitude/Types.swift

@@ -116,6 +116,10 @@ public protocol Plugin: AnyObject {
     func setup(amplitude: Amplitude)
     func execute(event: BaseEvent) -> BaseEvent?
     func teardown()
+    func onUserIdChanged(_ userId: String?)
+    func onDeviceIdChanged(_ deviceId: String?)
+    func onSessionIdChanged(_ sessionId: Int64)
+    func onOptOutChanged(_ optOut: Bool)
 }
 
 public protocol EventPlugin: Plugin {
@@ -138,6 +142,11 @@ extension Plugin {
     public func teardown(){
         // Clean up any resources from setup if necessary
     }
+
+    func onUserIdChanged(_ userId: String?) {}
+    func onDeviceIdChanged(_ deviceId: String?) {}
+    func onSessionIdChanged(_ sessionId: Int64) {}
+    func onOptOutChanged(_ optOut: Bool) {}
 }
 
 public protocol ResponseHandler {

Tests/AmplitudeTests/AmplitudeTests.swift

@@ -121,6 +121,78 @@ final class AmplitudeTests: XCTestCase {
         XCTAssertEqual(events.count, 1)
     }
 
+    func testPluginChangeNotifications() {
+        class TestPlugin: Plugin {
+            let type: PluginType = .enrichment
+
+            var deviceIdChanged: ((String?) -> Void)?
+            var sessionIdChanged: ((Int64?) -> Void)?
+            var userIdChanged: ((String?) -> Void)?
+            var optOutChanged: ((Bool) -> Void)?
+
+            func onDeviceIdChanged(_ deviceId: String?) {
+                deviceIdChanged?(deviceId)
+            }
+
+            func onSessionIdChanged(_ sessionId: Int64) {
+                sessionIdChanged?(sessionId)
+            }
+
+            func onUserIdChanged(_ userId: String?) {
+                userIdChanged?(userId)
+            }
+
+            func onOptOutChanged(_ optOut: Bool) {
+                optOutChanged?(optOut)
+            }
+        }
+
+        let testPlugin = TestPlugin()
+        let amplitude = Amplitude(configuration: Configuration(apiKey: "testPluginChangeNotifications",
+                                                               flushIntervalMillis: 1000000,
+                                                               optOut: false,
+                                                               storageProvider: FakeInMemoryStorage()))
+        amplitude.add(plugin: testPlugin)
+        amplitude.waitForTrackingQueue()
+
+        let expectedDeviceId = "test_device_id"
+        let deviceIdExpectation = expectation(description: "Should receive deviceId changes")
+        testPlugin.deviceIdChanged = { deviceId in
+            XCTAssertEqual(deviceId, expectedDeviceId)
+            XCTAssertEqual(amplitude.getDeviceId(), expectedDeviceId)
+            deviceIdExpectation.fulfill()
+        }
+        amplitude.setDeviceId(deviceId: expectedDeviceId)
+
+        let expectedSessionId = Int64(Date().timeIntervalSince1970 * 1000)
+        let sessionIdExpectation = expectation(description: "Should receive sessionId changes")
+        testPlugin.sessionIdChanged = { sessionId in
+            XCTAssertEqual(sessionId, expectedSessionId)
+            XCTAssertEqual(amplitude.getSessionId(), expectedSessionId)
+            sessionIdExpectation.fulfill()
+        }
+        amplitude.setSessionId(timestamp: expectedSessionId)
+
+        let expectedUserId = "test_user_id"
+        let userIdExpectation = expectation(description: "Should receive userId changes")
+        testPlugin.userIdChanged = { userId in
+            XCTAssertEqual(userId, expectedUserId)
+            XCTAssertEqual(amplitude.getUserId(), expectedUserId)
+            userIdExpectation.fulfill()
+        }
+        amplitude.setUserId(userId: expectedUserId)
+
+        let optOutExpectation = expectation(description: "Should receive optOut changes")
+        testPlugin.optOutChanged = { optOut in
+            XCTAssertTrue(optOut)
+            XCTAssertTrue(amplitude.configuration.optOut)
+            optOutExpectation.fulfill()
+        }
+        amplitude.configuration.optOut = true
+
+        waitForExpectations(timeout: 10)
+    }
+
     func testContextWithDisableTrackingOptions() {
         let apiKey = "testApiKeyForDisableTrackingOptions"
         let trackingOptions = TrackingOptions()