fix(ui): fix attachment download on web.

Signed-off-by: xsahil03x <xdsahil@gmail.com>

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

@@ -4,9 +4,41 @@ import 'package:dio/dio.dart';
 import 'package:file_selector/file_selector.dart';
 import 'package:stream_chat_flutter_core/stream_chat_flutter_core.dart';
 
-/// Downloads the [attachment] to the device and returns
-/// the path to the file.
-Future<String?> downloadWebOrDesktopAttachment(
+/// Represents the url and bytes of an attachment.
+class AttachmentData {
+  /// Creates a new [AttachmentData] instance.
+  const AttachmentData({
+    required this.bytes,
+    required this.downloadUrl,
+    required this.fileName,
+    this.mimeType,
+  });
+
+  /// The data downloaded from the [downloadUrl].
+  final Uint8List bytes;
+
+  /// The url of the attachment that was used to download the [bytes].
+  final String downloadUrl;
+
+  /// The name of the file to use when saving the [bytes].
+  final String fileName;
+
+  /// The mime type of the attachment.
+  final String? mimeType;
+
+  /// Creates an [XFile] from the [AttachmentData].
+  XFile toXFile({String? path}) {
+    return XFile.fromData(
+      bytes,
+      mimeType: mimeType,
+      name: fileName,
+      path: path,
+    );
+  }
+}
+
+/// Downloads the [attachment] and returns the [AttachmentData].
+Future<AttachmentData> downloadAttachmentData(
   Attachment attachment, {
   ProgressCallback? onReceiveProgress,
   Map<String, dynamic>? queryParameters,
@@ -34,13 +66,14 @@ Future<String?> downloadWebOrDesktopAttachment(
     fileName = attachment.title;
   }
 
-  assert(
-    downloadUrl != null,
-    'Attachment must have an assetUrl or imageUrl or thumbUrl',
-  );
+  if (downloadUrl == null) {
+    throw ArgumentError(
+      'Attachment must have an assetUrl or imageUrl or thumbUrl',
+    );
+  }
 
   final response = await Dio().get<List<int>>(
-    downloadUrl!,
+    downloadUrl,
     onReceiveProgress: onReceiveProgress,
     queryParameters: queryParameters,
     cancelToken: cancelToken,
@@ -49,23 +82,12 @@ Future<String?> downloadWebOrDesktopAttachment(
         Options(responseType: ResponseType.bytes),
   );
 
-  // Open the native file browser so the user can select the download path.
-  final path = await getSavePath(suggestedName: fileName);
+  final bytes = Uint8List.fromList(response.data!);
 
-  if (path == null) {
-    // Operation was canceled by the user.
-    return null;
-  }
-
-  // Create an XFile for proper file saving
-  final file = XFile.fromData(
-    Uint8List.fromList(response.data!),
+  return AttachmentData(
+    bytes: bytes,
+    downloadUrl: downloadUrl,
+    fileName: fileName!,
     mimeType: attachment.mimeType,
-    name: fileName,
-    path: path,
   );
-
-  // Save the file to the user's selected path.
-  await file.saveTo(path);
-  return path;
 }

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

@@ -50,13 +50,21 @@ class StreamAttachmentHandler extends StreamAttachmentHandlerBase {
     Map<String, dynamic>? queryParameters,
     CancelToken? cancelToken,
     Options? options,
-  }) {
-    return downloadWebOrDesktopAttachment(
+  }) async {
+    final data = await downloadAttachmentData(
       attachment,
       onReceiveProgress: onReceiveProgress,
       queryParameters: queryParameters,
       cancelToken: cancelToken,
       options: options,
     );
+
+    // Create an XFile for proper file saving.
+    final file = data.toXFile();
+
+    // Save the file. We are not using the path parameter because it is not
+    // supported on web.
+    await file.saveTo('');
+    return null;
   }
 }

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

@@ -1,8 +1,7 @@
 import 'dart:io';
-import 'dart:typed_data';
 
-import 'package:dio/dio.dart';
 import 'package:file_picker/file_picker.dart';
+import 'package:file_selector/file_selector.dart';
 import 'package:image_picker/image_picker.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:stream_chat_flutter/src/attachment/handler/common.dart';
@@ -21,14 +20,29 @@ class StreamAttachmentHandlerDesktop extends StreamAttachmentHandler {
     Map<String, dynamic>? queryParameters,
     CancelToken? cancelToken,
     Options? options,
-  }) {
-    return downloadWebOrDesktopAttachment(
+  }) async {
+    final data = await downloadAttachmentData(
       attachment,
       onReceiveProgress: onReceiveProgress,
       queryParameters: queryParameters,
       cancelToken: cancelToken,
       options: options,
     );
+
+    // Open the native file browser so the user can select the download path.
+    final path = await getSavePath(suggestedName: data.fileName);
+
+    if (path == null) {
+      // Operation was canceled by the user.
+      return null;
+    }
+
+    // Create an XFile for proper file saving.
+    final file = data.toXFile(path: path);
+
+    // Save the file to the user's selected path.
+    await file.saveTo(path);
+    return path;
   }
 }
 
@@ -160,53 +174,20 @@ class StreamAttachmentHandler extends StreamAttachmentHandlerBase {
     CancelToken? cancelToken,
     Options? options,
   }) async {
-    final type = attachment.type;
-
-    String? downloadUrl;
-    String? fileName;
-    /* ---IMAGES/GIFS--- */
-    if (type == 'image') {
-      downloadUrl = attachment.imageUrl ?? attachment.assetUrl;
-      fileName = attachment.title;
-      fileName ??= 'attachment.${attachment.mimeType ?? 'png'}';
-    }
-    /* ---GIPHY's--- */
-    else if (type == 'giphy') {
-      downloadUrl = attachment.thumbUrl;
-      fileName = '${attachment.title}.gif';
-    }
-    /* ---FILES AND VIDEOS--- */
-    else if (type == 'file' || type == 'video') {
-      downloadUrl = attachment.assetUrl;
-      fileName = attachment.title;
-    }
-
-    assert(
-      downloadUrl != null,
-      'Attachment must have an assetUrl or imageUrl or thumbUrl',
-    );
-
-    final response = await Dio().get<List<int>>(
-      downloadUrl!,
+    final data = await downloadAttachmentData(
+      attachment,
       onReceiveProgress: onReceiveProgress,
       queryParameters: queryParameters,
       cancelToken: cancelToken,
-      // set responseType to `bytes`
-      options: options?.copyWith(responseType: ResponseType.bytes) ??
-          Options(responseType: ResponseType.bytes),
+      options: options,
     );
 
     final appDir = await getTemporaryDirectory();
-    final ext = Uri.parse(downloadUrl).pathSegments.last;
+    final ext = Uri.parse(data.downloadUrl).pathSegments.last;
     final path = '${appDir.path}/${attachment.id}.$ext';
 
-    // Create an XFile for proper file saving
-    final file = XFile.fromData(
-      Uint8List.fromList(response.data!),
-      mimeType: attachment.mimeType,
-      name: fileName,
-      path: path,
-    );
+    // Create an XFile for proper file saving.
+    final file = data.toXFile(path: path);
 
     // Save the file to the user's selected path.
     await file.saveTo(path);