Extract status posting to separate class, convert to async/await

Tusker.xcodeproj/project.pbxproj

@@ -287,6 +287,7 @@
 		D6E426AD25334DA500C02E1C /* FuzzyMatcherTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6E426AC25334DA500C02E1C /* FuzzyMatcherTests.swift */; };
 		D6E426B325337C7000C02E1C /* CustomEmojiImageView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6E426B225337C7000C02E1C /* CustomEmojiImageView.swift */; };
 		D6E57FA325C26FAB00341037 /* Localizable.stringsdict in Resources */ = {isa = PBXBuildFile; fileRef = D6E57FA525C26FAB00341037 /* Localizable.stringsdict */; };
+		D6E9CDA8281A427800BBC98E /* PostService.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6E9CDA7281A427800BBC98E /* PostService.swift */; };
 		D6EAE0DB2550CC8A002DB0AC /* FocusableTextField.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6EAE0DA2550CC8A002DB0AC /* FocusableTextField.swift */; };
 		D6EBF01523C55C0900AE061B /* UIApplication+Scenes.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6EBF01423C55C0900AE061B /* UIApplication+Scenes.swift */; };
 		D6EBF01723C55E0D00AE061B /* UISceneSession+MastodonController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6EBF01623C55E0D00AE061B /* UISceneSession+MastodonController.swift */; };
@@ -635,6 +636,7 @@
 		D6E426B225337C7000C02E1C /* CustomEmojiImageView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CustomEmojiImageView.swift; sourceTree = "<group>"; };
 		D6E4885C24A2890C0011C13E /* Tusker.entitlements */ = {isa = PBXFileReference; lastKnownFileType = text.plist.entitlements; path = Tusker.entitlements; sourceTree = "<group>"; };
 		D6E57FA425C26FAB00341037 /* en */ = {isa = PBXFileReference; lastKnownFileType = text.plist.stringsdict; name = en; path = en.lproj/Localizable.stringsdict; sourceTree = "<group>"; };
+		D6E9CDA7281A427800BBC98E /* PostService.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PostService.swift; sourceTree = "<group>"; };
 		D6EAE0DA2550CC8A002DB0AC /* FocusableTextField.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = FocusableTextField.swift; sourceTree = "<group>"; };
 		D6EBF01423C55C0900AE061B /* UIApplication+Scenes.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UIApplication+Scenes.swift"; sourceTree = "<group>"; };
 		D6EBF01623C55E0D00AE061B /* UISceneSession+MastodonController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UISceneSession+MastodonController.swift"; sourceTree = "<group>"; };
@@ -1366,6 +1368,7 @@
 				D61959D2241E846D00A37B8E /* Models */,
 				D663626021360A9600C9CBA2 /* Preferences */,
 				D641C780213DD7C4004B4513 /* Screens */,
+				D6E9CDA6281A426700BBC98E /* Services */,
 				D62D241E217AA46B005076CC /* Shortcuts */,
 				D67B506B250B28FF00FAECFB /* Vendor */,
 				D6BED1722126661300F02DA0 /* Views */,
@@ -1422,6 +1425,14 @@
 			path = OpenInTusker;
 			sourceTree = "<group>";
 		};
+		D6E9CDA6281A426700BBC98E /* Services */ = {
+			isa = PBXGroup;
+			children = (
+				D6E9CDA7281A427800BBC98E /* PostService.swift */,
+			);
+			path = Services;
+			sourceTree = "<group>";
+		};
 		D6F1F84E2193B9BE00F5FE67 /* Caching */ = {
 			isa = PBXGroup;
 			children = (
@@ -1827,6 +1838,7 @@
 				D64AAE9726C88DC400FC57FB /* ToastConfiguration.swift in Sources */,
 				D6093FB025BE0B01004811E6 /* TrendingHashtagTableViewCell.swift in Sources */,
 				D63661C02381C144004B9E16 /* PreferencesNavigationController.swift in Sources */,
+				D6E9CDA8281A427800BBC98E /* PostService.swift in Sources */,
 				D6B053A223BD2C0600A066FA /* AssetPickerViewController.swift in Sources */,
 				D6EE63FB2551F7F60065485C /* StatusCollapseButton.swift in Sources */,
 				D627944A23A6AD6100D38C68 /* BookmarksTableViewController.swift in Sources */,

Tusker/Screens/Compose/ComposeView.swift

@@ -10,16 +10,49 @@ import SwiftUI
 import Pachyderm
 import Combine
 
+@propertyWrapper struct OptionalStateObject<T: ObservableObject>: DynamicProperty {
+    private class Republisher: ObservableObject {
+        var cancellable: AnyCancellable?
+        var wrapped: T? {
+            didSet {
+                cancellable?.cancel()
+                cancellable = wrapped?.objectWillChange
+                    .receive(on: RunLoop.main)
+                    .sink { [unowned self] _ in
+                        self.objectWillChange.send()
+                    }
+            }
+        }
+    }
+    
+    @StateObject private var republisher = Republisher()
+    @State private var object: T?
+    var wrappedValue: T? {
+        get {
+            object
+        }
+        nonmutating set {
+            object = newValue
+        }
+    }
+    
+    func update() {
+        republisher.wrapped = wrappedValue
+    }
+}
+
 struct ComposeView: View {
     @ObservedObject var draft: Draft
     @EnvironmentObject var mastodonController: MastodonController
     @EnvironmentObject var uiState: ComposeUIState
     
-    @State private var isPosting = false
+    @OptionalStateObject private var poster: PostService?
-    @State private var postProgress: Double = 0
-    @State private var postTotalProgress: Double = 0
     @State private var isShowingPostErrorAlert = false
-    @State private var postError: PostError?
+    @State private var postError: PostService.Error?
+    
+    private var isPosting: Bool {
+        poster != nil
+    }
     
     private let stackPadding: CGFloat = 8
     
@@ -58,9 +91,9 @@ struct ComposeView: View {
                 }
             }
             
-            if postProgress > 0 {
+            if let poster = poster {
                 // can't use SwiftUI.ProgressView because there's no UIProgressView.Style.bar equivalent, see FB8587149
-                WrappedProgressView(value: postProgress, total: postTotalProgress)
+                WrappedProgressView(value: poster.currentStep, total: poster.totalSteps)
             }
             
             autocompleteSuggestions
@@ -123,6 +156,7 @@ struct ComposeView: View {
             // the list rows provide their own padding, so we cancel out the extra spacing from the VStack
             .padding([.top, .bottom], -8)
         }
+        .disabled(isPosting)
         .padding(stackPadding)
         .padding(.bottom, uiState.autocompleteState != nil ? 46 : nil)
     }
@@ -147,7 +181,11 @@ struct ComposeView: View {
     }
     
     private var postButton: some View {
-        Button(action: self.postStatus) {
+        Button {
+            Task {
+                await self.postStatus()
+            }
+        } label: {
             Text("Post")
         }
         .disabled(!postButtonEnabled)
@@ -184,179 +222,31 @@ struct ComposeView: View {
         ])
     }
     
-    private func postStatus() {
+    private func postStatus() async {
-        guard draft.hasContent else { return }
+        guard !isPosting,
-        
+              draft.hasContent else {
-        isPosting = true
-        
-        // save before posting, so if a crash occurs during network request, the status won't be lost
-        DraftsManager.save()
-        
-        let contentWarning = draft.contentWarningEnabled ? draft.contentWarning : nil
-        let sensitive = contentWarning != nil
-        
-        // 2 steps (request data, then upload) for each attachment
-        postTotalProgress = Double(2 + (draft.attachments.count * 2))
-        postProgress = 1
-        
-        uploadAttachments { (result) in
-            switch result {
-            case let .failure(error):
-                self.isShowingPostErrorAlert = true
-                self.postError = error
-                self.postProgress = 0
-                self.postTotalProgress = 0
-                self.isPosting = false
-            
-            case let .success(uploadedAttachments):
-                let request = Client.createStatus(text: draft.textForPosting(on: mastodonController.instanceFeatures),
-                                                  contentType: Preferences.shared.statusContentType,
-                                                  inReplyTo: draft.inReplyToID,
-                                                  media: uploadedAttachments,
-                                                  sensitive: sensitive,
-                                                  spoilerText: contentWarning,
-                                                  visibility: draft.visibility,
-                                                  language: nil,
-                                                  pollOptions: draft.poll?.options.map(\.text),
-                                                  pollExpiresIn: draft.poll == nil ? nil : Int(draft.poll!.duration),
-                                                  pollMultiple: draft.poll?.multiple,
-                                                  localOnly: mastodonController.instanceFeatures.instanceType == .hometown ? draft.localOnly : nil)
-                self.mastodonController.run(request) { (response) in
-                    switch response {
-                    case let .failure(error):
-                        self.isShowingPostErrorAlert = true
-                        self.postError = error
-
-                    case .success(_, _):
-                        self.postProgress += 1
-                        
-                        DraftsManager.shared.remove(self.draft)
-                        
-                        // wait .25 seconds so the user can see the progress bar has completed
-                        DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(250)) {
-                            self.uiState.delegate?.dismissCompose(mode: .post)
-                        }
-                    }
-                }
-            }
-        }
-    }
-    
-    private func uploadAttachments(_ completion: @escaping (Result<[Attachment], AttachmentUploadError>) -> Void) {
-        let group = DispatchGroup()
-        
-        var attachmentDataResults = [Result<(Data, String), CompositionAttachmentData.Error>?]()
-        
-        for (index, compAttachment) in draft.attachments.enumerated() {
-            group.enter()
-            
-            attachmentDataResults.append(nil)
-            
-            compAttachment.data.getData { (result) in
-                postProgress += 1
-                
-                attachmentDataResults[index] = result
-                group.leave()
-            }
-        }
-        
-        group.notify(queue: .global(qos: .userInitiated)) {
-            
-            var anyFailed = false
-            var uploadedAttachments = [Result<Attachment, Error>?]()
-        
-            // Mastodon does not respect the order of the `media_ids` parameter in the create post request,
-            // it determines attachment order by which was uploaded first. Since the upload attachment request
-            // does not include any timestamp data, and requests may arrive at the server out-of-order,
-            // attachments need to be uploaded serially in order to ensure the order of attachments in the
-            // posted status reflects order the user set.
-            // Pleroma does respect the order of the `media_ids` parameter.
-            
-            let datas: [(Data, String)]
-            do {
-                datas = try attachmentDataResults.map { try $0!.get() }
-            } catch {
-                completion(.failure(AttachmentUploadError(errors: [error])))
             return
         }
         
-            for (index, (data, mimeType)) in datas.enumerated() {
+        let poster = PostService(mastodonController: mastodonController, draft: draft)
-                group.enter()
+        self.poster = poster
         
-                let compAttachment = draft.attachments[index]
+        do {
-                let formAttachment = FormAttachment(mimeType: mimeType, data: data, fileName: "file")
+            try await poster.post()
-                let request = Client.upload(attachment: formAttachment, description: compAttachment.attachmentDescription)
-                self.mastodonController.run(request) { (response) in
-                    switch response {
-                    case let .failure(error):
-                        uploadedAttachments.append(.failure(error))
-                        anyFailed = true
             
-                    case let .success(attachment, _):
+            // wait .25 seconds so the user can see the progress bar has completed
-                        self.postProgress += 1
+            try? await Task.sleep(nanoseconds: 250_000_000)
-                        uploadedAttachments.append(.success(attachment))
+            
+            uiState.delegate?.dismissCompose(mode: .post)
+            
+        } catch let error as PostService.Error {
+            self.isShowingPostErrorAlert = true
+            self.postError = error
+        } catch {
+            fatalError("Unreachable")
         }
         
-                    group.leave()
+        self.poster = nil
-                }
-                
-                group.wait()
-            }
-            
-            
-            if anyFailed {
-                let errors = uploadedAttachments.map { (result) -> Error? in
-                    if case let .failure(error) = result {
-                        return error
-                    } else {
-                        return nil
-                    }
-                }
-                completion(.failure(AttachmentUploadError(errors: errors)))
-            } else {
-                let uploadedAttachments = uploadedAttachments.map {
-                    try! $0!.get()
-                }
-                completion(.success(uploadedAttachments))
-            }
-
-        }
-    }
-}
-
-fileprivate protocol PostError: LocalizedError {}
-
-extension PostError {
-    var localizedDescription: String {
-        if let self = self as? Client.Error {
-            return self.localizedDescription
-        } else if let self = self as? AttachmentUploadError {
-            return self.localizedDescription
-        } else {
-            return "Unknown Error"
-        }
-    }
-}
-
-extension Client.Error: PostError {}
-
-fileprivate struct AttachmentUploadError: PostError {
-    let errors: [Error?]
-    
-    var localizedDescription: String {
-        return errors.enumerated().compactMap { (index, error) -> String? in
-            guard let error = error else { return nil }
-            let description: String
-            // need to downcast to use more specific localizedDescription impl from Pachyderm
-            if let error = error as? Client.Error {
-                description = error.localizedDescription
-            } else if let error = error as? CompositionAttachmentData.Error {
-                description = error.localizedDescription
-            } else {
-                description = error.localizedDescription
-            }
-            return "Attachment \(index + 1): \(description)"
-        }.joined(separator: ",\n")
     }
 }
 

Tusker/Services/PostService.swift

@@ -0,0 +1,122 @@
+//
+//  PostService.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 4/27/22.
+//  Copyright © 2022 Shadowfacts. All rights reserved.
+//
+
+import Foundation
+import Pachyderm
+
+class PostService: ObservableObject {
+    private let mastodonController: MastodonController
+    private let draft: Draft
+    let totalSteps: Int
+    
+    @Published var currentStep = 1
+    
+    init(mastodonController: MastodonController, draft: Draft) {
+        self.mastodonController = mastodonController
+        self.draft = draft
+        // 2 steps (request data, then upload) for each attachment
+        self.totalSteps = 2 + (draft.attachments.count * 2)
+    }
+    
+    @MainActor
+    func post() async throws {
+        guard draft.hasContent else {
+            return
+        }
+        
+        // save before posting, so if a crash occurs during network request, the status won't be lost
+        DraftsManager.save()
+        
+        let uploadedAttachments = try await uploadAttachments()
+        
+        let contentWarning = draft.contentWarningEnabled ? draft.contentWarning : nil
+        let sensitive = contentWarning != nil
+        
+        let request = Client.createStatus(
+            text: draft.textForPosting(on: mastodonController.instanceFeatures),
+            contentType: Preferences.shared.statusContentType,
+            inReplyTo: draft.inReplyToID,
+            media: uploadedAttachments,
+            sensitive: sensitive,
+            spoilerText: contentWarning,
+            visibility: draft.visibility,
+            language: nil,
+            pollOptions: draft.poll?.options.map(\.text),
+            pollExpiresIn: draft.poll == nil ? nil : Int(draft.poll!.duration),
+            pollMultiple: draft.poll?.multiple,
+            localOnly: mastodonController.instanceFeatures.localOnlyPosts ? draft.localOnly : nil
+        )
+        do {
+            let (_, _) = try await mastodonController.run(request)
+            currentStep += 1
+            
+            DraftsManager.shared.remove(self.draft)
+        } catch let error as Client.Error {
+            throw Error.posting(error)
+        }
+    }
+    
+    private func uploadAttachments() async throws -> [Attachment] {
+        var attachments: [Attachment] = []
+        attachments.reserveCapacity(draft.attachments.count)
+        for (index, attachment) in draft.attachments.enumerated() {
+            let data: Data
+            let mimeType: String
+            do {
+                (data, mimeType) = try await getData(for: attachment)
+                currentStep += 1
+            } catch let error as CompositionAttachmentData.Error {
+                throw Error.attachmentData(index: index, cause: error)
+            }
+            do {
+                let uploaded = try await uploadAttachment(data: data, mimeType: mimeType, description: attachment.description)
+                attachments.append(uploaded)
+                currentStep += 1
+            } catch let error as Client.Error {
+                throw Error.attachmentUpload(index: index, cause: error)
+            }
+        }
+        return attachments
+    }
+    
+    private func getData(for attachment: CompositionAttachment) async throws -> (Data, String) {
+        return try await withCheckedThrowingContinuation { continuation in
+            attachment.data.getData { result in
+                switch result {
+                case let .success(res):
+                    continuation.resume(returning: res)
+                case let .failure(error):
+                    continuation.resume(throwing: error)
+                }
+            }
+        }
+    }
+    
+    private func uploadAttachment(data: Data, mimeType: String, description: String?) async throws -> Attachment {
+        let formAttachment = FormAttachment(mimeType: mimeType, data: data, fileName: "file")
+        let req = Client.upload(attachment: formAttachment, description: description)
+        return try await mastodonController.run(req).0
+    }
+    
+    enum Error: Swift.Error, LocalizedError {
+        case attachmentData(index: Int, cause: CompositionAttachmentData.Error)
+        case attachmentUpload(index: Int, cause: Client.Error)
+        case posting(Client.Error)
+        
+        var localizedDescription: String {
+            switch self {
+            case let .attachmentData(index: index, cause: cause):
+                return "Attachment \(index + 1): \(cause.localizedDescription)"
+            case let .attachmentUpload(index: index, cause: cause):
+                return "Attachment \(index + 1): \(cause.localizedDescription)"
+            case let .posting(error):
+                return error.localizedDescription
+            }
+        }
+    }
+}

Tusker/Views/WrappedProgressView.swift

@@ -11,8 +11,8 @@ import SwiftUI
 struct WrappedProgressView: UIViewRepresentable {
     typealias UIViewType = UIProgressView
     
-    let value: Double
+    let value: Int
-    let total: Double
+    let total: Int
     
     func makeUIView(context: Context) -> UIProgressView {
         return UIProgressView(progressViewStyle: .bar)
@@ -20,7 +20,9 @@ struct WrappedProgressView: UIViewRepresentable {
     
     func updateUIView(_ uiView: UIProgressView, context: Context) {
         if total > 0 {
-            uiView.setProgress(Float(value / total), animated: true)
+            let progress = Float(value) / Float(total)
+            print(progress)
+            uiView.setProgress(progress, animated: true)
         } else {
             uiView.setProgress(0, animated: true)
         }