iOS: Share Extension (share to Noo) via an App Group inbox

ShareExtension target copies shared files into group.dev.ayushya.noo and leaves a manifest; the app consumes it on launch/activation through the existing share_intent channel into the destination picker. Extension is embedded before Flutter's script phases; versions follow FLUTTER_BUILD_*. Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
2026-10-06 19:23:37 -04:00
parent 8b86aa8f34
commit 525504bc47
10 changed files with 637 additions and 12 deletions
@@ -0,0 +1,92 @@
+import Foundation
+
+/// The App Group both the app and its Share Extension belong to - the one
+/// place they can exchange files.
+enum AppGroup {
+  static let identifier = "group.dev.ayushya.noo"
+
+  static var containerURL: URL? {
+    FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: identifier)
+  }
+}
+
+/// One file the Share Extension copied into the group container.
+struct SharedItem: Codable, Equatable {
+  let path: String
+  let name: String
+  let mimeType: String?
+  let size: Int64
+}
+
+/// Files the Share Extension received, waiting for the app to ask the user
+/// where to upload them. The extension appends; the app consumes (reads and
+/// clears) when it launches or becomes active. Compiled into both targets.
+///
+/// Layout under `<root>/SharedInbox/`: `pending.json` (the manifest) and one
+/// `<batch-id>/` folder per share holding the copied files.
+enum SharedInbox {
+  static let folderName = "SharedInbox"
+  private static let manifestName = "pending.json"
+
+  static func directory(in root: URL) -> URL {
+    root.appendingPathComponent(folderName, isDirectory: true)
+  }
+
+  /// A fresh folder for one share's files.
+  static func makeBatchDirectory(in root: URL) throws -> URL {
+    let dir = directory(in: root).appendingPathComponent(UUID().uuidString, isDirectory: true)
+    try FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
+    return dir
+  }
+
+  static func append(_ items: [SharedItem], in root: URL) throws {
+    guard !items.isEmpty else { return }
+    try withManifestLock(in: root) {
+      let existing = (try? readManifest(in: root)) ?? []
+      try writeManifest(existing + items, in: root)
+    }
+  }
+
+  /// Everything pending, dropping entries whose file has gone missing, and
+  /// clears the manifest so each share is delivered once.
+  static func consume(in root: URL) -> [SharedItem] {
+    var items: [SharedItem] = []
+    try? withManifestLock(in: root) {
+      items = ((try? readManifest(in: root)) ?? []).filter {
+        FileManager.default.fileExists(atPath: $0.path)
+      }
+      try? FileManager.default.removeItem(at: manifestURL(in: root))
+    }
+    return items
+  }
+
+  private static func manifestURL(in root: URL) -> URL {
+    directory(in: root).appendingPathComponent(manifestName)
+  }
+
+  private static func readManifest(in root: URL) throws -> [SharedItem] {
+    let data = try Data(contentsOf: manifestURL(in: root))
+    return try JSONDecoder().decode([SharedItem].self, from: data)
+  }
+
+  private static func writeManifest(_ items: [SharedItem], in root: URL) throws {
+    try FileManager.default.createDirectory(
+      at: directory(in: root), withIntermediateDirectories: true)
+    try JSONEncoder().encode(items).write(to: manifestURL(in: root), options: .atomic)
+  }
+
+  /// The extension and the app are separate processes that can both touch the
+  /// manifest, so read-modify-write goes through a file coordinator.
+  private static func withManifestLock(in root: URL, _ body: () throws -> Void) throws {
+    try FileManager.default.createDirectory(
+      at: directory(in: root), withIntermediateDirectories: true)
+    var coordinationError: NSError?
+    var thrown: Error?
+    NSFileCoordinator().coordinate(
+      writingItemAt: directory(in: root), options: [], error: &coordinationError
+    ) { _ in
+      do { try body() } catch { thrown = error }
+    }
+    if let error = coordinationError ?? thrown.map({ $0 as NSError }) { throw error }
+  }
+}