[cross_file] Updates cross_file to a package separated federated plugin by bparrishMines · Pull Request #11010 · flutter/packages

bparrishMines · 2026-02-12T19:49:37Z

Updates cross_file to a package separated federated plugin. ~~Keeping the package separation is still debatable.~~

Follows the general design outlined at https://flutter.dev/go/flutter-file-system

Fixes flutter/flutter#91869

Implementation is split into

cross_file_io: for use cases supportable by dart:io (all platforms except Web)
cross_file_web: for Web
- Uses Blobs and Blob URLs.
- Supports package:web Files (subclass of Blob.
cross_file_android: for Android Scoped Storage
- Uses the high level abstraction of DocumentFile to interact with content uris.
- Uses Kotlin.
cross_file_darwin: for iOS and macOS App Sandbox
- Creates implementation for security scoped URI that call:
  - Adds support to call URL.startAccessingSecurityScopedResource and URL.stopaccessingsecurityscopedresource.
  - Future Work: Adds support to bookmark URLs following: https://developer.apple.com/documentation/Security/accessing-files-from-the-macos-app-sandbox#Persist-file-access-with-security-scoped-URL-bookmarks
- Creates implementation for accessing an asset with PhotoKit.

Pubspec dependencies have been changed to use ones from git to have runnable example apps while in development and review. Specifically because file_selector uses the current version of cross_file and I didn't want to make this a file_selector + cross_file PR. Can update it to this if preferred.

The reason file_selector is different for the example apps is because I wanted to ensue Android, iOS, macOS still work without copying the file to a file with the Apps sandbox.

Example

dependencies:
  cross_file:
    git:
      url: https://github.com/bparrishMines/packages
      ref: new_crossfile
      path: packages/cross_file/cross_file
  file_selector:
    git:
      url: https://github.com/bparrishMines/packages
      ref: new_file_selector
      path: packages/file_selector/file_selector

The cross_file example will run for all platforms.

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stuartmorgan-g · 2026-05-11T17:23:07Z

+  assets:
+    - assets/hello.txt
+
+dependency_overrides:


Why is this an override and not the actual dependency?

stuartmorgan-g · 2026-05-11T17:29:08Z

+
+/// The common superclass for [XFile] and [XDirectory].
+@immutable
+class XEntity {


Should this maybe XFilesystemEntity to make it clearer what it's for and less likely to collide with other things? That would also be consistent with the Dart IO class names.

stuartmorgan-g · 2026-05-11T18:41:28Z

+  @internal
+  final PlatformXEntity platform;
+
+  /// A string used to reference the resource's location.


Nit: "identifier" rather than "location", since we are using the term "uri".

stuartmorgan-g · 2026-05-11T18:50:48Z

+  /// Provides a nonnull platform class extension.
+  ///
+  /// Will throw an exception if the specified platform extension can not be
+  /// returned.


I've been thinking about this more; under what circumstances would this be safe to call? It's up to the platform implementation what extension (if any) to return, and that's an implementation detail of the platform, so clients shouldn't rely on knowing it.

Should we just have S? getExtension?

stuartmorgan-g · 2026-05-11T18:52:13Z

+  /// the resource.
+  Future<Uint8List> readAsBytes() => platform.readAsBytes();
+
+  /// Reads the entire resource contents as a string using the given Encoding.


[Encoding]

stuartmorgan-g · 2026-07-08T18:29:05Z

+  @override
+  Stream<Uint8List> openRead([int? start, int? end]) {
+    assert(start == null || start >= 0);
+    assert(end == null || end >= (start ?? 0));


Don't these need to throw ArgumentError, rather than just assert in debug?

stuartmorgan-g · 2026-07-08T18:30:27Z

+    void dataReceivedHandler(NSData data) {
+      final Uint8List bytes = _extractBytesToUint8List(data);
+
+      runOnPlatformThread(() {


TODO to remove these once thread merging is non-optional on macOS?

Actually, wait, does this code work on macOS without thread merging? It looks like this is being used to make the Dart code run on the Dart main isolate's thread, which isn't going to be the platform thread in that case.

Maybe we can't implement this code with FFI yet after all?

stuartmorgan-g · 2026-07-08T18:40:38Z

Please add a CONTRIBUTING.md explaining the use of this, as in path_provider_foundation.

stuartmorgan-g · 2026-07-08T18:50:32Z

+`XFile` on the web platform is backed by [Blob](https://api.dart.dev/be/180361/dart-html/Blob-class.html)
+objects and their URLs.
+
+It seems that Safari hangs when reading Blobs larger than 4GB (your app will stop without returning


Isn't this (and the related next paragraph) no longer applicable to this version of the package?

stuartmorgan-g · 2026-07-08T18:50:47Z

+
+[![Data on Global support for Blob URLs](https://caniuse.bitsofco.de/image/bloburls.png)](https://caniuse.com/bloburls)
+
+### Tests


This should move to a CONTRIBING.md

bparrishMines added 30 commits January 21, 2026 13:17

export extensions and add exception docs

dd280a2

half of file tests

0373d5e

dart unit tests for file

38eb1d9

directory tests

51a74e2

add stuff and stuff

97f60a6

cross file impl

bfb9e0a

add context for android example

ae1aaf3

Merge branch 'main' of github.com:flutter/packages into new_crossfile

aac47fe

update to new impl

e419342

generally rewrite readme

295ea46

default implementations for cross file implementations

39d4bbc

add tests for default impl

fa7f420

update docs

b88d137

add base test files

e57c8bb

fix platform implementations

cf7239e

directory tests

4201466

scoped storage tests

16c61f7

Merge branch 'main' of github.com:flutter/packages into new_crossfile

4ae04b7

update replace

da418ab

remove unused path dep

55c6078

flutter create init

410451f

add txt file

d4bb9c8

update pubspec but no work

224ac8c

update to github dependencies

f91cc32

example version solved

3420f3d

delet e cross_file_ios

e825b1a

compiling code

5a773b1

undo file_selector changes

abb58f2

fix failing unit tests

1fe476d

some lints

3179eae

license

6613d68

github-actions Bot removed the CICD Run CI/CD label Jun 17, 2026

bparrishMines added the CICD Run CI/CD label Jun 17, 2026

bparrishMines added 6 commits June 17, 2026 12:58

use --platform

6a68362

dash

aa6e666

add darwin dep

5c26447

remove configs

6c5f597

fix license

eba22d5

Merge branch 'main' of github.com:flutter/packages into new_crossfile

77a6224

github-actions Bot removed the CICD Run CI/CD label Jun 17, 2026

bparrishMines added the CICD Run CI/CD label Jun 17, 2026

bparrishMines requested a review from stuartmorgan-g June 18, 2026 14:11

bparrishMines added 5 commits June 18, 2026 12:51

fix web test requiring SIGKILL

43b9fb0

Merge branch 'main' of github.com:flutter/packages into new_crossfile

0f3283c

update to use ffigen

49ae634

use ffigen

a2d34bd

Merge branch 'main' of github.com:flutter/packages into new_crossfile

a7de454

github-actions Bot removed the CICD Run CI/CD label Jun 23, 2026

add flutter deps

8517b1b

flutter-dashboard Bot added the CICD Run CI/CD label Jun 23, 2026

bparrishMines added 9 commits June 23, 2026 16:12

add dart test yaml

44e0676

rename to actual file name

356487a

delete

1b2f361

fix integration test macos

50cffbe

remove chrome requirement

ace90a2

move tests to integration tests

a0a4c85

Merge branch 'main' of github.com:flutter/packages into new_crossfile

44d1df6

add test for range filter

d37cb36

Merge branch 'main' of github.com:flutter/packages into new_crossfile

1627c9f

stuartmorgan-g requested changes Jul 8, 2026

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[cross_file] Updates cross_file to a package separated federated plugin #11010

[cross_file] Updates cross_file to a package separated federated plugin #11010
bparrishMines wants to merge 362 commits into
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bparrishMines commented Feb 12, 2026 •

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		[![Data on Global support for Blob URLs](https://caniuse.bitsofco.de/image/bloburls.png)](https://caniuse.com/bloburls)

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bparrishMines commented Feb 12, 2026 •

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