Flutter Web throws on Platform.is* #36126

rostopira · 2019-07-13T10:54:56Z

Using master branch

Flutter 1.8.2-pre.30 • channel master • https://github.com/flutter/flutter.git
Framework • revision 13382f41c0 (4 hours ago) • 2019-07-12 23:24:04 -0700
Engine • revision 919e353236
Tools • Dart 2.5.0 (build 2.5.0-dev.1.0 24725a8559)

Sample code:

void main() async {
    var isAndroid = Platform.isAndroid; //Crashes right here
    //...
}

flutter run -d chrome

Uncaught (in promise) Error: Unsupported operation: Platform._operatingSystem
    at Object.throw_ [as throw] (dart_sdk.js:3995)
    at Function._operatingSystem (dart_sdk.js:43981)
    at Function.get operatingSystem [as operatingSystem] (dart_sdk.js:44030)
    at get _operatingSystem (dart_sdk.js:43943)
    at Function.desc.get [as _operatingSystem] (dart_sdk.js:5024)
    at get isAndroid (dart_sdk.js:43964)
    at Function.desc.get [as isAndroid] (dart_sdk.js:5024)
    at main$ (main.dart:11)
    at main$.next (<anonymous>)
    at runBody (dart_sdk.js:28865)
    at Object._async [as async] (dart_sdk.js:28893)
    at Object.main$ [as main] (main.dart:9)
    at main (main_web_entrypoint.dart:6)
    at main.next (<anonymous>)
    at onValue (dart_sdk.js:28846)
    at async._RootZone.new.runUnary (dart_sdk.js:28734)
    at _FutureListener.then.handleValue (dart_sdk.js:24660)
    at handleValueCallback (dart_sdk.js:25127)
    at Function._propagateToListeners (dart_sdk.js:25159)
    at async._AsyncCallbackEntry.new.callback (dart_sdk.js:24913)
    at Object._microtaskLoop (dart_sdk.js:28945)
    at _startMicrotaskLoop (dart_sdk.js:28951)
    at dart_sdk.js:25361

The text was updated successfully, but these errors were encountered:

jonahwilliams · 2019-07-13T18:49:25Z

We definitely need some better documentation describing this issue, but the gist is that dart:io is not really supported when compiling for the web. Instead of using Platform.isAndroid, you will be able to use either defaultTargetPlatform or Theme.platform. I say will, because the browser detection for Android/iOS is not yet implemented for the web (see https://github.com/flutter/flutter/blob/master/packages/flutter/lib/src/foundation/_platform_web.dart).

rostopira · 2019-07-13T19:02:07Z

Well, but could it don't crash at least? Or always return false? Or at least throw exception that could be caught with try/catch?
Even pure dart packages tend to use Platform.is* sometimes

Also, is there are anyway to detect running on web?

jonahwilliams · 2019-07-13T19:10:48Z

Always returning false would be wrong though, you could very well be on an Android phone.

jonahwilliams · 2019-07-13T19:18:48Z

See #36135 for a technique to detect running on the web

yjbanov · 2019-07-18T22:28:47Z

/cc @kevmoo @vsmenon

kevmoo · 2019-07-18T22:41:02Z

Always returning false would be wrong though, you could very well be on an Android phone.

Need to be VERY careful here.

Do we want to introduce an orthogonal concept of isWeb vs isAndroid.

Worth a discussion doc at the least.

kevmoo · 2019-07-18T22:41:47Z

I'd vote for introducing platform.dart in flutter to handle this case and to start migrating folks to it.

I believe this is what we discussed WRT platform-specific code, right @jonahwilliams ?

jonahwilliams · 2019-07-18T23:00:49Z

What we have today is conditional based:

https://github.com/flutter/flutter/blob/master/packages/flutter/lib/src/foundation/_platform_io.dart
https://github.com/flutter/flutter/blob/master/packages/flutter/lib/src/foundation/_platform_web.dart

vsmenon · 2019-07-25T19:42:09Z

Note, we'd prefer disallowing importing dart:io altogether on the Web - i.e., give a compile time error. Today (at least for now), we allow importing, but throw at runtime.

We should be able to prevent imports for Flutter Web at least by editing Flutter's version of libraries.json.

vsmenon · 2019-08-08T18:17:37Z

Upstream issue:

dart-lang/sdk#35969

KodyDevSAGAR · 2019-12-10T10:40:56Z

is there any workaround for the same ? still facing the same problem. Caught error: Unsupported operation: Platform._operatingSystem

TannerYoung · 2019-12-13T14:28:05Z

Just want to add that this is thrown by https://pub.dev/packages/google_sign_in as well if attempted to use with the flutter web beta version 1.13.1-pre.99

bean5 · 2020-02-15T00:45:38Z

Dupe of #50843. This adds more information to the table, but its title doesn't follow the template notation regarding web bugs, so it might get overlooked.

esDotDev · 2020-03-05T16:09:54Z

Is this really a dupe? The other bug is asking about package_info, this is just about the Platform.is booleans. It's pretty crazy that our builds are blowing up just because we're trying to check a static boolean. Why can't this just be set at build time?

Currently there's literally no way to check what platform you are on without blowing up on web. Which is kinda crazy for a platform aiming to be universal.

bean5 · 2020-03-08T14:05:04Z

Precisely why I think this is strange problem to have. In my very effort to support web, my stuff crashes. It might even build. I'm using janky work-arounds that depend on context instead. Very annoying to have to pass context to a static tool I built for detection that would otherwise just call this instead. In other words, I'm not using this because it breaks web support.

esDotDev · 2020-03-08T15:07:49Z

fwiw, either of these packages can be used to workaround the platform detection:
https://pub.dev/packages/universal_io
https://pub.dev/packages/universal_platform

bean5 · 2020-05-08T22:43:22Z

Seems strange to depend on another project for something like this. Maybe when Flutter for web is officially supported it won't be necessary. One can hope.

talhashahab786 · 2020-05-19T07:40:29Z

use kIsWeb

import 'package:flutter/foundation.dart';

if (!kIsWeb) FlutterStatusbarcolor.setStatusBarColor(Color(redLong)); //code that runs for mobile

esDotDev · 2021-03-14T05:24:41Z

You don't need to install any additional package.

Just do this instead to check if flutter is executed in the web browser:
import 'package:flutter/foundation.dart' show kIsWeb;

Usage:
if (kIsWeb) { print('do this'); } else { print('do that'); }

The issue is going the other way... if MacOS do something, or if Windows do something, you then can no longer run the codebase in the browser.

It really defies comprehension that the upstream never tries fixing the strange problem or giving any explicit explanation on development guides since 2019. 😕
Even falling back on "default" or null will be a much more practicable solution.

Agreed it is extremely odd to throw exceptions on a bunch of static bools, and to not simply figure out a practical solution for 2 yrs.

Then again, I wrote UniversalPlatform and it works pretty good :)

tpal-dev · 2021-03-28T00:57:32Z

This code should help in situation when you use windows size plugin for desktop size and on web throw error "Error: Unsupported operation: Platform._operatingSystem..."

in main.dart file you have to check if it is not a web mode, then check if Platform.is..:

import 'dart:io' show Platform;
import 'package:flutter/foundation.dart' show kIsWeb;
import 'package:flutter/material.dart';
import 'package:window_size/window_size.dart';

void main() {
  WidgetsFlutterBinding.ensureInitialized();
  if (!kIsWeb) {
    if (Platform.isWindows || Platform.isLinux || Platform.isMacOS) {
      setWindowMinSize(const Size(400, 600));
      setWindowMaxSize(const Size(800, double.infinity));
      setWindowFrame(Rect.fromLTRB(0, 0, 600.0, 1000.0));
    }
  }

  runApp(MyApp());
}

lukepighetti · 2021-03-29T22:29:12Z

We just had our web app explode because we added a Platform.isWindows check to avoid initializing Firebase services. Is there any solution available for this issue? This is a very unfortunate limitation if not.

EDIT: we did this with if(kIsWeb || !Platform.isWindows) initialize firebase

omartinma · 2021-04-09T09:01:13Z

Any update on that? I have a web app that I need to check if I'm running it on and mobile or desktop browser

escamoteur · 2021-05-12T10:31:10Z

Just ran into this myself. Indeed this should not crash.

FernandoUFS · 2021-06-01T18:22:17Z

And actually I'm not able to create a web version of my app because some dependencies are checking Platform.isAndroid and Platform.isIOS without check kIsWeb. I think this would be important when launching flutter 2.0 with web at "stable" channel. I only have to wait for this to work on web to launch the web version.

creativecreatorormaybenot · 2021-06-01T18:52:25Z

@FernandoUFS You can contribute to the dependencies :)

esDotDev · 2021-06-01T18:55:05Z

And actually I'm not able to create a web version of my app because some dependencies are checking Platform.isAndroid and Platform.isIOS without check kIsWeb. I think this would be important when launching flutter 2.0 with web at "stable" channel. I only have to wait for this to work on web to launch the web version.

That's why I wrote this: https://pub.dev/packages/universal_platform

AdrienLemaire · 2022-08-03T08:33:38Z

The beginner's codelab uses Platform.is* and crashes with the same error

https://codelabs.developers.google.com/codelabs/flutter-boring-to-beautiful#2

source:
https://github.com/flutter/codelabs/blob/main/boring_to_beautiful/step_01/lib/main.dart#L16

It would be nice to have bug-free codelabs :) PR added at flutter/codelabs#1053

danagbemava-nc · 2024-02-20T13:05:51Z

Reproducible on the latest versions of flutter.

Updating labels

flutter doctor -v

[✓] Flutter (Channel stable, 3.19.0, on macOS 14.3.1 23D60 darwin-arm64, locale en-GB)
    • Flutter version 3.19.0 on channel stable at /Users/nexus/dev/sdks/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision bae5e49bc2 (6 days ago), 2024-02-13 17:46:18 -0800
    • Engine revision 04817c99c9
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    • All Android licenses accepted.

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[✓] Chrome - develop for the web
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[✓] VS Code (version 1.86.2)
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[✓] Connected device (4 available)
    • Dean’s iPad (mobile) • 00008103-000825C811E3401E • ios            • iOS 17.3.1 21D61
    • Nexus (mobile)       • 00008020-001875E83A38002E • ios            • iOS 17.3.1 21D61
    • macOS (desktop)      • macos                     • darwin-arm64   • macOS 14.3.1 23D60 darwin-arm64
    • Chrome (web)         • chrome                    • web-javascript • Google Chrome 121.0.6167.184

[✓] Network resources
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• No issues found!

[!] Flutter (Channel master, 3.20.0-10.0.pre.50, on macOS 14.3.1 23D60 darwin-arm64, locale en-GB)
    • Flutter version 3.20.0-10.0.pre.50 on channel master at /Users/nexus/dev/sdks/flutters
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    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 2d422a3261 (7 hours ago), 2024-02-19 21:49:05 -0800
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    • If those were intentional, you can disregard the above warnings; however it is recommended to use "git" directly to perform update checks and upgrades.

[✓] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
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[✓] VS Code (version 1.86.2)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.82.0

[✓] Connected device (5 available)
    • Dean’s iPad (mobile)            • 00008103-000825C811E3401E • ios            • iOS 17.3.1 21D61
    • Nexus (mobile)                  • 00008020-001875E83A38002E • ios            • iOS 17.3.1 21D61
    • macOS (desktop)                 • macos                     • darwin-arm64   • macOS 14.3.1 23D60 darwin-arm64
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[✓] Network resources
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! Doctor found issues in 1 category.

yjbanov · 2024-03-28T20:01:56Z

We did what we could on the Flutter side (#36126 (comment)). The remaining work, if any, is in the Dart SDK (see details in this closed issue: dart-lang/sdk#35969).

Closing as fixed.

github-actions · 2024-04-15T07:00:44Z

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.

jonahwilliams added the platform-web Web applications specifically label Jul 13, 2019

yjbanov added the dependency: dart Dart team may need to help us label Jul 18, 2019

yjbanov added this to the Goals milestone Jul 18, 2019

kasp1 mentioned this issue Sep 12, 2019

Temporary fix for flutter-web compatibility. stryder-dev/flutter_platform_widgets#79

Closed

BondarenkoStas mentioned this issue Oct 17, 2019

[Cloud Firestore] Unsupported operation: Platform._operatingSystem firebase/flutterfire#1257

Closed

jmagman mentioned this issue Oct 28, 2019

defaultTargetPlatform on web thinks it's Android #43633

Closed

mariamhas added the customer: webeap label Jan 28, 2020

This was referenced Mar 28, 2020

Show a SnackBar and copy the url to be shared to Clipboard to support web WorldHealthOrganization/app#507

Closed

Enhanced status bar background text color. WorldHealthOrganization/app#533

Closed

kf6gpe added the P2 Important issues not at the top of the work list label May 29, 2020

This was referenced Jun 11, 2020

[web] Check web before Platform.isX parse-community/Parse-SDK-Flutter#391

Closed

[web] Check web before Platform.isX parse-community/Parse-SDK-Flutter#392

Merged

esDotDev mentioned this issue Jun 16, 2021

Update advice for platform detection flutter/website#5929

Merged

Josehdez96 mentioned this issue Dec 30, 2021

Chrome error: Unsupported operation: Platform._operatingSystem superlistapp/super_editor#372

Closed

CodeIdeal added a commit to CodeIdeal/realworld_flutter that referenced this issue Feb 11, 2022

for solve flutter web issue: flutter/flutter#36126 (comment)

74d69b3

prologikus mentioned this issue Apr 30, 2022

Unsupported operation: Platform.operatingSystem knoxpo/dart_algolia#94

Closed

AdrienLemaire mentioned this issue Aug 3, 2022

fix: codelab example step01 Platform.is* call (#36126) flutter/codelabs#1053

Merged

4 tasks

ghost mentioned this issue Jun 14, 2023

[Web, MacOS] Uncaught Unsupported operation: Platform._operatingSystem miguelpruivo/flutter_file_picker#1307

Closed

flutter-triage-bot bot added multiteam-retriage-candidate team-web Owned by Web platform team triaged-web Triaged by Web platform team labels Jul 8, 2023

danagbemava-nc added found in release: 3.19 Found to occur in 3.19 found in release: 3.20 Found to occur in 3.20 and removed found in release: 1.21 Found to occur in 1.21 found in release: 1.26 Found to occur in 1.26 multiteam-retriage-candidate labels Feb 20, 2024

remonh87 mentioned this issue Mar 2, 2024

Uncaught Unsupported operation: Platform._operatingSystem when deployed to firebase hosting for web flutter-stripe/flutter_stripe#1618

Closed

yjbanov closed this as completed Mar 28, 2024

danagbemava-nc added the r: fixed Issue is closed as already fixed in a newer version label Apr 1, 2024

github-actions bot locked as resolved and limited conversation to collaborators Apr 15, 2024

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Flutter Web throws on Platform.is* #36126

Flutter Web throws on Platform.is* #36126

rostopira commented Jul 13, 2019 •

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yjbanov commented Jul 18, 2019

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vsmenon commented Jul 25, 2019

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omartinma commented Apr 9, 2021

escamoteur commented May 12, 2021

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github-actions bot commented Apr 15, 2024

Flutter Web throws on Platform.is* #36126

Flutter Web throws on Platform.is* #36126

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rostopira commented Jul 13, 2019 • edited Loading

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yjbanov commented Jul 18, 2019

kevmoo commented Jul 18, 2019

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jonahwilliams commented Jul 18, 2019

vsmenon commented Jul 25, 2019

vsmenon commented Aug 8, 2019

KodyDevSAGAR commented Dec 10, 2019

TannerYoung commented Dec 13, 2019

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