Refactoring

Metatext.xcodeproj/project.pbxproj

@@ -15,6 +15,8 @@
 		D0091B6F24DD68090040E8D2 /* PreferencesView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0091B6D24DD68090040E8D2 /* PreferencesView.swift */; };
 		D0091B7124DD68220040E8D2 /* PreferencesViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0091B7024DD68220040E8D2 /* PreferencesViewModel.swift */; };
 		D0091B7224DD68220040E8D2 /* PreferencesViewModel.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0091B7024DD68220040E8D2 /* PreferencesViewModel.swift */; };
+		D0091B7424DDF4860040E8D2 /* IdentifiedEnvironment.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0091B7324DDF4860040E8D2 /* IdentifiedEnvironment.swift */; };
+		D0091B7524DDF4860040E8D2 /* IdentifiedEnvironment.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0091B7324DDF4860040E8D2 /* IdentifiedEnvironment.swift */; };
 		D047FAAE24C3E21200AF17C5 /* MetatextApp.swift in Sources */ = {isa = PBXBuildFile; fileRef = D047FA8524C3E21000AF17C5 /* MetatextApp.swift */; };
 		D047FAAF24C3E21200AF17C5 /* MetatextApp.swift in Sources */ = {isa = PBXBuildFile; fileRef = D047FA8524C3E21000AF17C5 /* MetatextApp.swift */; };
 		D047FAB224C3E21200AF17C5 /* Assets.xcassets in Resources */ = {isa = PBXBuildFile; fileRef = D047FA8724C3E21200AF17C5 /* Assets.xcassets */; };
@@ -171,6 +173,7 @@
 		D0091B6A24DC10CE0040E8D2 /* PostingReadingPreferencesViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PostingReadingPreferencesViewModel.swift; sourceTree = "<group>"; };
 		D0091B6D24DD68090040E8D2 /* PreferencesView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesView.swift; sourceTree = "<group>"; };
 		D0091B7024DD68220040E8D2 /* PreferencesViewModel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PreferencesViewModel.swift; sourceTree = "<group>"; };
+		D0091B7324DDF4860040E8D2 /* IdentifiedEnvironment.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = IdentifiedEnvironment.swift; sourceTree = "<group>"; };
 		D047FA8524C3E21000AF17C5 /* MetatextApp.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MetatextApp.swift; sourceTree = "<group>"; };
 		D047FA8724C3E21200AF17C5 /* Assets.xcassets */ = {isa = PBXFileReference; lastKnownFileType = folder.assetcatalog; path = Assets.xcassets; sourceTree = "<group>"; };
 		D047FA8C24C3E21200AF17C5 /* Metatext.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Metatext.app; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -358,6 +361,7 @@
 				D0666A4424C6BC0A00F3F04B /* DatabaseError.swift */,
 				D052BBCE24D750C000A80A7A /* Defaults.swift */,
 				D0666A5324C6C3E500F3F04B /* Emoji.swift */,
+				D0091B7324DDF4860040E8D2 /* IdentifiedEnvironment.swift */,
 				D0666A4A24C6C37700F3F04B /* Identity.swift */,
 				D0666A4124C6BB7B00F3F04B /* IdentityDatabase.swift */,
 				D0666A4D24C6C39600F3F04B /* Instance.swift */,
@@ -690,6 +694,7 @@
 				D0BEC94724CA22C400E864C4 /* TimelineViewModel.swift in Sources */,
 				D0666A4E24C6C39600F3F04B /* Instance.swift in Sources */,
 				D0ED1BDA24CF963E00B4899C /* AppAuthorizationEndpoint.swift in Sources */,
+				D0091B7424DDF4860040E8D2 /* IdentifiedEnvironment.swift in Sources */,
 				D052BBCF24D750C000A80A7A /* Defaults.swift in Sources */,
 				D0ED1BE324CFA84400B4899C /* MastodonError.swift in Sources */,
 				D0666A6324C6DC6C00F3F04B /* AppAuthorization.swift in Sources */,
@@ -764,6 +769,7 @@
 				D0BEC94824CA22C400E864C4 /* TimelineViewModel.swift in Sources */,
 				D0666A4F24C6C39600F3F04B /* Instance.swift in Sources */,
 				D0ED1BDB24CF963E00B4899C /* AppAuthorizationEndpoint.swift in Sources */,
+				D0091B7524DDF4860040E8D2 /* IdentifiedEnvironment.swift in Sources */,
 				D052BBD024D750C000A80A7A /* Defaults.swift in Sources */,
 				D0ED1BE424CFA84400B4899C /* MastodonError.swift in Sources */,
 				D0666A6424C6DC6C00F3F04B /* AppAuthorization.swift in Sources */,

Shared/Extensions/Publisher+Extensions.swift

@@ -16,4 +16,24 @@ extension Publisher {
         }
         .eraseToAnyPublisher()
     }
+
+    func continuingIfWeakReferenceIsStillAlive<T: AnyObject>(to object: T) -> AnyPublisher<(Output, T), Error> {
+        tryMap { [weak object] in
+            guard let object = object else { throw WeakReferenceError.deallocated }
+
+            return ($0, object)
+        }
+        .tryCatch { error -> Empty<(Output, T), Never> in
+            if case WeakReferenceError.deallocated = error {
+                return Empty()
+            }
+
+            throw error
+        }
+        .eraseToAnyPublisher()
+    }
+}
+
+private enum WeakReferenceError: Error {
+    case deallocated
 }

Shared/Model/AppEnvironment.swift

@@ -1,7 +1,6 @@
 // Copyright © 2020 Metabolist. All rights reserved.
 
 import Foundation
-import Combine
 
 struct AppEnvironment {
     let URLSessionConfiguration: URLSessionConfiguration
@@ -10,41 +9,3 @@ struct AppEnvironment {
     let secrets: Secrets
     let webAuthSessionType: WebAuthSession.Type
 }
-
-class IdentifiedEnvironment {
-    @Published var identity: Identity
-    let observationErrors: AnyPublisher<Error, Never>
-    let networkClient: MastodonClient
-    let appEnvironment: AppEnvironment
-
-    private var cancellables = Set<AnyCancellable>()
-    private let observationErrorsInput = PassthroughSubject<Error, Never>()
-
-    init(identityID: String, appEnvironment: AppEnvironment) throws {
-        self.appEnvironment = appEnvironment
-        observationErrors = observationErrorsInput.eraseToAnyPublisher()
-        networkClient = MastodonClient(configuration: appEnvironment.URLSessionConfiguration)
-        networkClient.accessToken = try appEnvironment.secrets.item(.accessToken, forIdentityID: identityID)
-
-        let observation = appEnvironment.identityDatabase.identityObservation(id: identityID).share()
-
-        var initialIdentity: Identity?
-
-        observation.first().sink(
-            receiveCompletion: { _ in },
-            receiveValue: { initialIdentity = $0 })
-            .store(in: &cancellables)
-
-        guard let identity = initialIdentity else { throw IdentityDatabaseError.identityNotFound }
-
-        self.identity = identity
-        networkClient.instanceURL = identity.url
-
-        observation.catch { [weak self] error -> Empty<Identity, Never> in
-            self?.observationErrorsInput.send(error)
-
-            return Empty()
-        }
-        .assign(to: &$identity)
-    }
-}

Shared/Model/IdentifiedEnvironment.swift

@@ -0,0 +1,82 @@
+// Copyright © 2020 Metabolist. All rights reserved.
+
+import Foundation
+import Combine
+
+class IdentifiedEnvironment {
+    @Published var identity: Identity
+    let observationErrors: AnyPublisher<Error, Never>
+
+    private let networkClient: MastodonClient
+    private let appEnvironment: AppEnvironment
+    private let observationErrorsInput = PassthroughSubject<Error, Never>()
+    private var cancellables = Set<AnyCancellable>()
+
+    init(identityID: String, appEnvironment: AppEnvironment) throws {
+        self.appEnvironment = appEnvironment
+        observationErrors = observationErrorsInput.eraseToAnyPublisher()
+        networkClient = MastodonClient(configuration: appEnvironment.URLSessionConfiguration)
+        networkClient.accessToken = try appEnvironment.secrets.item(.accessToken, forIdentityID: identityID)
+
+        let observation = appEnvironment.identityDatabase.identityObservation(id: identityID).share()
+
+        var initialIdentity: Identity?
+
+        observation.first().sink(
+            receiveCompletion: { _ in },
+            receiveValue: { initialIdentity = $0 })
+            .store(in: &cancellables)
+
+        guard let identity = initialIdentity else { throw IdentityDatabaseError.identityNotFound }
+
+        self.identity = identity
+        networkClient.instanceURL = identity.url
+
+        observation.catch { [weak self] error -> Empty<Identity, Never> in
+            self?.observationErrorsInput.send(error)
+
+            return Empty()
+        }
+        .assign(to: &$identity)
+    }
+}
+
+extension IdentifiedEnvironment {
+    var isAuthorized: Bool { networkClient.accessToken != nil }
+
+    func verifyCredentials() -> AnyPublisher<Void, Error> {
+        networkClient.request(AccountEndpoint.verifyCredentials)
+            .continuingIfWeakReferenceIsStillAlive(to: self)
+            .map { ($0, $1.identity.id) }
+            .flatMap(appEnvironment.identityDatabase.updateAccount)
+            .eraseToAnyPublisher()
+    }
+
+    func refreshServerPreferences() -> AnyPublisher<Void, Error> {
+        networkClient.request(PreferencesEndpoint.preferences)
+            .continuingIfWeakReferenceIsStillAlive(to: self)
+            .map { ($1.identity.preferences.updated(from: $0), $1.identity.id) }
+            .flatMap(appEnvironment.identityDatabase.updatePreferences)
+            .eraseToAnyPublisher()
+    }
+
+    func refreshInstance() -> AnyPublisher<Void, Error> {
+        networkClient.request(InstanceEndpoint.instance)
+            .continuingIfWeakReferenceIsStillAlive(to: self)
+            .map { ($0, $1.identity.id) }
+            .flatMap(appEnvironment.identityDatabase.updateInstance)
+            .eraseToAnyPublisher()
+    }
+
+    func identitiesObservation() -> AnyPublisher<[Identity], Error> {
+        appEnvironment.identityDatabase.identitiesObservation()
+    }
+
+    func recentIdentitiesObservation() -> AnyPublisher<[Identity], Error> {
+        appEnvironment.identityDatabase.recentIdentitiesObservation(excluding: identity.id)
+    }
+
+    func updatePreferences(_ preferences: Identity.Preferences) -> AnyPublisher<Void, Error> {
+        appEnvironment.identityDatabase.updatePreferences(preferences, forIdentityID: identity.id)
+    }
+}

Shared/View Models/IdentitiesViewModel.swift

@@ -15,7 +15,7 @@ class IdentitiesViewModel: ObservableObject {
         self.environment = environment
         identity = environment.identity
 
-        environment.appEnvironment.identityDatabase.identitiesObservation()
+        environment.identitiesObservation()
             .assignErrorsToAlertItem(to: \.alertItem, on: self)
             .assign(to: &$identities)
     }

Shared/View Models/MainNavigationViewModel.swift

@@ -18,8 +18,7 @@ class MainNavigationViewModel: ObservableObject {
         identity = environment.identity
         environment.$identity.dropFirst().assign(to: &$identity)
 
-        environment.appEnvironment.identityDatabase
+        environment.recentIdentitiesObservation()
-            .recentIdentitiesObservation(excluding: environment.identity.id)
             .assignErrorsToAlertItem(to: \.alertItem, on: self)
             .assign(to: &$recentIdentities)
     }
@@ -27,31 +26,21 @@ class MainNavigationViewModel: ObservableObject {
 
 extension MainNavigationViewModel {
     func refreshIdentity() {
-        let id = identity.id
+        if environment.isAuthorized {
-
+            environment.verifyCredentials()
-        if environment.networkClient.accessToken != nil {
-            environment.networkClient.request(AccountEndpoint.verifyCredentials)
-                .map { ($0, id) }
-                .flatMap(environment.appEnvironment.identityDatabase.updateAccount)
                 .assignErrorsToAlertItem(to: \.alertItem, on: self)
                 .sink(receiveValue: {})
                 .store(in: &cancellables)
 
             if identity.preferences.useServerPostingReadingPreferences {
-                let capturedPreferences = identity.preferences
+                environment.refreshServerPreferences()
-
-                environment.networkClient.request(PreferencesEndpoint.preferences)
-                    .map { (capturedPreferences.updated(from: $0), id) }
-                    .flatMap(environment.appEnvironment.identityDatabase.updatePreferences)
                     .assignErrorsToAlertItem(to: \.alertItem, on: self)
                     .sink(receiveValue: {})
                     .store(in: &cancellables)
             }
         }
 
-        environment.networkClient.request(InstanceEndpoint.instance)
+        environment.refreshInstance()
-            .map { ($0, id) }
-            .flatMap(environment.appEnvironment.identityDatabase.updateInstance)
             .assignErrorsToAlertItem(to: \.alertItem, on: self)
             .sink(receiveValue: {})
             .store(in: &cancellables)

Shared/View Models/PostingReadingPreferencesViewModel.swift

@@ -21,16 +21,13 @@ class PostingReadingPreferencesViewModel: ObservableObject {
             .removeDuplicates()
             .handleEvents(receiveOutput: { [weak self] in
                 if $0.useServerPostingReadingPreferences {
-                    self?.refreshPreferences()
+                    self?.refreshServerPreferences()
                 }
             })
             .assign(to: &$preferences)
 
-        let id = environment.identity.id
-
         $preferences.dropFirst()
-            .map { ($0, id) }
+            .flatMap(environment.updatePreferences)
-            .flatMap(environment.appEnvironment.identityDatabase.updatePreferences)
             .assignErrorsToAlertItem(to: \.alertItem, on: self)
             .sink(receiveValue: {})
             .store(in: &cancellables)
@@ -38,13 +35,8 @@ class PostingReadingPreferencesViewModel: ObservableObject {
 }
 
 extension PostingReadingPreferencesViewModel {
-    func refreshPreferences() {
+    private func refreshServerPreferences() {
-        let id = environment.identity.id
+        environment.refreshServerPreferences()
-        let capturedPreferences = preferences
-
-        environment.networkClient.request(PreferencesEndpoint.preferences)
-            .map { (capturedPreferences.updated(from: $0), id) }
-            .flatMap(environment.appEnvironment.identityDatabase.updatePreferences)
             .assignErrorsToAlertItem(to: \.alertItem, on: self)
             .sink(receiveValue: {})
             .store(in: &cancellables)