fix(ui): migrate to file_picker 12

melos.yaml

@@ -52,7 +52,7 @@ command:
       # upper bounds once FlutterFire ships a fixed release.
       firebase_crashlytics: '>=5.2.0 <5.2.5'
       firebase_messaging: '>=16.0.0 <16.4.2'
-      file_picker: ^11.0.0
+      file_picker: '>=12.0.0 <14.0.0'
       file_selector: ^1.1.0
       app_badge_plus: ^1.3.2
       flutter_local_notifications: ^21.0.0

packages/stream_chat_flutter/CHANGELOG.md

@@ -1,5 +1,9 @@
 ## Upcoming
 
+🛑️ Breaking
+
+- `PlatformFileX.toAttachmentFile` and `PlatformFileX.toAttachment` are now asynchronous, returning `Future<AttachmentFile>` and `Future<Attachment>`. `file_picker` 12 removed `PlatformFile`'s eagerly-loaded `bytes` and `size` getters, so the content is read on demand; this matches the existing `XFileX` extensions. Any `PlatformFile` you hold came from `FilePicker.pickFiles()`, whose return type also changed in `file_picker` 12, so that call site needs rewriting anyway and the added `await` goes in the same edit.
+
 ✅ Added
 
 - Added `StreamMessageItem.semanticsLabel`, which replaces the announcement composed for a message row, and `StreamMessageItem.excludeFromSemantics`, which leaves the row unlabeled so the bubble and footer announce their own parts.
@@ -8,6 +12,9 @@
 
 ⚠️ Changed
 
+- Bumped `file_picker` to `>=12.0.0 <14.0.0`.
+- Deprecated `withData` and `withReadStream` on `StreamAttachmentHandler.pickFile` and `StreamFilePicker`. Content is now read on demand, so both are ignored.
+- Android apps built from a Flutter template older than 3.44 must add `subprojects { project.evaluationDependsOn(":app") }` to their root `android/build.gradle`. Without it the build fails with `cannot find symbol: class FilePickerPlugin`, an error that says nothing about its cause.
 - Video thumbnails now use `stream_thumbnail` on every platform, and the `thumblr`
   dependency is gone.
 - Linux builds now need the FFmpeg and libwebp development packages — on Debian/Ubuntu:
@@ -17,6 +24,7 @@
 
 🐞 Fixed
 
+- Fixed `StreamAttachmentHandler.pickFile` throwing when the picker returned an empty selection: it took `.files.first` unconditionally. It now returns `null`.
 - Fixed `StreamAttachmentHandler` throwing `UnimplementedError` on WebAssembly builds.
 - Improved the screen-reader experience in the message list: each message is announced as a single phrase naming the sender, the body, the time, the edited marker and the delivery status, while the attachments, reaction chips, quoted message and replies row stay reachable one level deeper.
 - Fixed the message body being announced as its markdown source, so link and emphasis syntax is no longer read aloud.

packages/stream_chat_flutter/lib/src/attachment/handler/stream_attachment_handler_base.dart

@@ -32,8 +32,8 @@ abstract class StreamAttachmentHandlerBase {
     List<String>? allowedExtensions,
     Function(FilePickerStatus)? onFileLoading,
     int compressionQuality = 0,
-    bool withData = true,
-    bool withReadStream = false,
+    @Deprecated('Content is read on demand; this no longer has any effect.') bool withData = true,
+    @Deprecated('Content is read on demand; this no longer has any effect.') bool withReadStream = false,
     bool lockParentWindow = true,
   }) {
     throw UnimplementedError('pickFile is not implemented');

packages/stream_chat_flutter/lib/src/attachment/handler/stream_attachment_handler_html.dart

@@ -22,23 +22,22 @@ class StreamAttachmentHandler extends StreamAttachmentHandlerBase {
     List<String>? allowedExtensions,
     Function(FilePickerStatus)? onFileLoading,
     int compressionQuality = 0,
-    bool withData = true,
-    bool withReadStream = false,
+    @Deprecated('Content is read on demand; this no longer has any effect.') bool withData = true,
+    @Deprecated('Content is read on demand; this no longer has any effect.') bool withReadStream = false,
     bool lockParentWindow = true,
   }) async {
-    final result = await FilePicker.pickFiles(
+    final result = await FilePicker.pickFile(
       dialogTitle: dialogTitle,
       initialDirectory: initialDirectory,
       type: type,
       allowedExtensions: allowedExtensions,
       onFileLoading: onFileLoading,
       compressionQuality: compressionQuality,
-      withData: withData,
-      withReadStream: withReadStream,
-      lockParentWindow: lockParentWindow,
+      windowsOptions: WindowsOptions(lockParentWindow: lockParentWindow),
+      linuxOptions: LinuxOptions(lockParentWindow: lockParentWindow),
     );
 
-    return result?.files.first.toAttachment(type: type.toAttachmentType());
+    return await result?.toAttachment(type: type.toAttachmentType());
   }
 
   @override

packages/stream_chat_flutter/lib/src/attachment/handler/stream_attachment_handler_io.dart

@@ -131,23 +131,22 @@ class StreamAttachmentHandler extends StreamAttachmentHandlerBase {
     List<String>? allowedExtensions,
     Function(FilePickerStatus)? onFileLoading,
     int compressionQuality = 0,
-    bool withData = true,
-    bool withReadStream = false,
+    @Deprecated('Content is read on demand; this no longer has any effect.') bool withData = true,
+    @Deprecated('Content is read on demand; this no longer has any effect.') bool withReadStream = false,
     bool lockParentWindow = true,
   }) async {
-    final result = await FilePicker.pickFiles(
+    final result = await FilePicker.pickFile(
       dialogTitle: dialogTitle,
       initialDirectory: initialDirectory,
       type: type,
       allowedExtensions: allowedExtensions,
       onFileLoading: onFileLoading,
       compressionQuality: compressionQuality,
-      withData: withData,
-      withReadStream: withReadStream,
-      lockParentWindow: lockParentWindow,
+      windowsOptions: WindowsOptions(lockParentWindow: lockParentWindow),
+      linuxOptions: LinuxOptions(lockParentWindow: lockParentWindow),
     );
 
-    return result?.files.first.toAttachment(type: type.toAttachmentType());
+    return await result?.toAttachment(type: type.toAttachmentType());
   }
 
   @override

packages/stream_chat_flutter/lib/src/message_input/attachment_picker/options/stream_file_picker.dart

@@ -19,8 +19,8 @@ class StreamFilePicker extends StatelessWidget {
     this.allowedExtensions,
     this.onFileLoading,
     this.compressionQuality = 0,
-    this.withData = false,
-    this.withReadStream = false,
+    @Deprecated('Content is read on demand; this no longer has any effect.') this.withData = false,
+    @Deprecated('Content is read on demand; this no longer has any effect.') this.withReadStream = false,
     this.lockParentWindow = false,
   });
 
@@ -46,9 +46,11 @@ class StreamFilePicker extends StatelessWidget {
   final int compressionQuality;
 
   /// Whether to include the file data in the [Attachment].
+  @Deprecated('Content is read on demand; this no longer has any effect.')
   final bool withData;
 
   /// Whether to include the file read stream in the [Attachment].
+  @Deprecated('Content is read on demand; this no longer has any effect.')
   final bool withReadStream;
 
   /// Whether to lock the parent window when the file picker is open.
@@ -69,8 +71,6 @@ class StreamFilePicker extends StatelessWidget {
           allowedExtensions: allowedExtensions,
           onFileLoading: onFileLoading,
           compressionQuality: compressionQuality,
-          withData: withData,
-          withReadStream: withReadStream,
           lockParentWindow: lockParentWindow,
         );
       });

packages/stream_chat_flutter/lib/src/utils/extensions.dart

@@ -116,19 +116,22 @@ extension IterableExtension<T> on Iterable<T> {
 /// Useful extension for [PlatformFile]
 extension PlatformFileX on PlatformFile {
   /// Converts the [PlatformFile] into [AttachmentFile]
-  AttachmentFile get toAttachmentFile {
+  ///
+  /// Reads the file content on demand, so the result is asynchronous.
+  Future<AttachmentFile> get toAttachmentFile async {
+    final bytes = await readAsBytes();
     return AttachmentFile(
       // Path is not supported on web.
       path: CurrentPlatform.isWeb ? null : path,
       name: name,
+      size: bytes.length,
       bytes: bytes,
-      size: size,
     );
   }
 
   /// Converts the [PlatformFile] to a [Attachment].
-  Attachment toAttachment({required String type}) {
-    final file = toAttachmentFile;
+  Future<Attachment> toAttachment({required String type}) async {
+    final file = await toAttachmentFile;
     final extraDataMap = <String, Object>{};
 
     final mimeType = file.mediaType?.mimeType;

packages/stream_chat_flutter/pubspec.yaml

@@ -30,7 +30,7 @@ dependencies:
   diacritic: ^0.1.6
   dio: ^5.11.0
   ezanimation: ^0.6.0
-  file_picker: ^11.0.0
+  file_picker: '>=12.0.0 <14.0.0'
   file_selector: ^1.1.0
   flutter:
     sdk: flutter

sample_app/android/build.gradle

@@ -25,6 +25,17 @@ subprojects {
 
 }
 
+// Plugin projects evaluate before `:app` by default, but the Flutter Gradle
+// plugin only registers the `flutter` extension on them while `:app` is being
+// configured. A plugin whose build script reads that extension at configuration
+// time — android_file_picker, pulled in by file_picker 12 — fails without this.
+// Present in the current Flutter app template; this module predates it. Kept in
+// its own block, after the one above: forcing evaluation from inside that block
+// would run `:app` before its `afterEvaluate` is registered.
+subprojects {
+    project.evaluationDependsOn(":app")
+}
+
 tasks.register("clean", Delete) {
     delete rootProject.layout.buildDirectory
 }