No named parameter with the name 'vsync'.

[xfqwdsj]

New Issue Checklist

• I am not disclosing a vulnerability.
• I am not just asking a question.
• I have searched through existing issues.
• I can reproduce the issue with the latest version of Parse Server and the Parse Flutter SDK.

Issue Description

When I built my app, I got an error: parse_server_sdk_flutter-4.0.0/lib/src/utils/parse_live_list.dart(276,9): error GC6690633: No named parameter with the name 'vsync'.

Steps to reproduce

Building Windows app.

Actual Outcome

The build fails with the error No named parameter with the name 'vsync'.

Expected Outcome

The build was successful.

Environment

Parse Flutter SDK

• SDK version: 4.0.0
• Operating system version: Windows 11 Build 22621.1413

Server

• Parse Server version: 6.0.0

Logs

parse_server_sdk_flutter-4.0.0/lib/src/utils/parse_live_list.dart(276,9): error GC6690633: No named parameter with the name 'vsync'.

Additional content

My Flutter version is Channel flutter-3.9-candidate.15, 3.9.0-15.0.pre, in this version, vsync parameter seems to be removed, I can manually delete the property specification of vsync in the downloaded SDK to fix this problem. This means that the solution to this problem can be as simple as removing a few lines of code from the SDK.

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[Nidal-Bakir]

Can you test this on the Flutter stable channel? it seems that the bug is related to the Flutter framework, not the SDK

[xfqwdsj]

Can you test this on the Flutter stable channel? it seems that the bug is related to the Flutter framework, not the SDK

In the documentation for Flutter's AnimatedSize Class, the vsync property no longer exists, so this is an API change. I guess the SDK should no longer provide that property to AnimatedSize.

[mtrezza]

What is the range of Flutter SDK versions that the Parse Flutter SDK currently supports?

[xfqwdsj]

What is the range of Flutter SDK versions that the Parse Flutter SDK currently supports?

Sorry, I admit I was a little presumptuous and impatient. But this property was indeed removed from Flutter - or will be. I also noticed that there is a comment in the code for ignoring deprecation warnings that there are indications that this property will be removed. Anyway, I think removing it now would be useful, even if it's too early.

[mtrezza]

Usually how this works is that certain features are only made available based on the underlying framework version. Not sure if that is possible in Flutter? Could we detect the Flutter SDK version inside our code and just remove the property if the version doesn't fit?

Also where do we specify the Flutter SDK version compatibility? I think we need a compatibility table?

[Nidal-Bakir]

No need to do anything about this property removal it was deprecated since Flutter 2.2.xx Apr 15 21
and the latest stable release of Flutter is 3.7.8 Mar 22 23

More than 2 years of deprecation, plus no one uses Flutter 2.x.x the whole community migrated to Flutter >=3.0.0

From the source code of flutter:

@deprecated(
'This field is now ignored. '
'This feature was deprecated after v2.2.0-10.1.pre.'
)

So, the only affected users are those who are still using Flutter versions <2.2.0, which is not common in the Flutter community and is discouraged. I think in nodejs I guess it is normal to use node 16 while node 17 or 18 is out because my friend still uses node 16 for some projects. on the other hand in the Flutter world, it is not normal at all to not use the latest stable release of the framework.

Also where do we specify the Flutter SDK version compatibility?

In the pubspec.yaml file under the environment section:
the current environment constraint is on the SDK only (Dart)

environment:
  sdk: ">=2.12.0 <3.0.0"

This implies that we can use any Flutter version that uses any Dart SDK version that is less than 3.0.0 and greater than or equal to 2.12.0

If we need to constraint the Flutter version we need to add a constraint entry like this:

environment:
  sdk: ">=2.12.0 <3.0.0"
  flutter: ">=3.0.0 <4.0.0" # any flutter version greater than or equal to 3.0.0 but less than 4.0.0

[mtrezza]

So, the only affected users are those who are still using Flutter versions <2.2.0, which is not common in the Flutter community and is discouraged.

If it is technically possible that there is an app out there that uses Flutter <2.2.0 and the vsync property via the Parse Flutter SDK, then we need to consider the removal of the property a breaking change.

If we need to constraint the Flutter version we need to add a constraint entry like this

I think it makes sense to add this constraint. Adding the constraint is a breaking change in itself. With that we'll release Flutter 5.x.

[Nidal-Bakir]

I think it makes sense to add this constraint. Adding the constraint is a breaking change in itself. With that we'll release Flutter 5.x.

Sure, we can do that

here is what we need to add:

environment:
  sdk: ">=2.17.0 <3.0.0" # any Dart version that is greater than or equal to 2.17.0 and less than 3.0.0
  flutter: ">=3.0.0"  # any Flutter version that is greater than or equal to 3.0.0

These are the recommended constraints from the flutter tame. these constraints are used by default when creating a Flutter package. When we add these constraints the SDK will not be compatible with Flutter <3.0.0

If we need to do that for the Flutter package then we should do the same thing for the Dart package like this:

environment:
  sdk: ">=2.17.0 <3.0.0" 
 

[mtrezza]

Current values:

Parse-SDK-Flutter/packages/dart/pubspec.yaml

Lines 6 to 7 in d7339cd

	environment:
	sdk: ">=2.12.0 <3.0.0"

Parse-SDK-Flutter/packages/flutter/pubspec.yaml

Lines 6 to 7 in d7339cd

	environment:
	sdk: ">=2.12.0 <3.0.0"

If we change the range in the dart package then we'll also have to release dart 5.0. What is the reason for bumping the lower bound of the range from >=2.12.0 to >=2.17.0?

Does the Dart SDK / Flutter SDK have release cycles? Do they plan when to deprecate older versions, or how does that work?

[Nidal-Bakir]

What is the reason for bumping the lower bound of the range from >=2.12.0 to >=2.17.0?

The main reason for raising the minimum required version of the language is to make new language features available. For example, suppose feature X was introduced in Dart version 2.17.0. Even if our code's version constraints are wide, such as '>=2.12.0 <3.0.0', we cannot use feature X because what if the code runs on a Dart version earlier than 2.17.0? This is because the Dart compiler cannot know which Dart versions the code will run on. Therefore, if our minimum Dart version is lower than 2.17.0, the compiler will NOT allow us to use a feature added in 2.17.0. And this thing applies to the Flutter constraints.

Does the Dart SDK / Flutter SDK have release cycles? Do they plan when to deprecate older versions, or how does that work?

Yes, there is. see releases
but you see there is no release cycle for bug fixes for example those have a special release cycle maybe every two weeks or mouth something like that.

Well, at the end of the day, it's up to us to decide if we still want to support older versions of the framework.
what do I mean by that? if someone opens an issue about a bug in the SDK with Flutter 2.2.x and Dart 2.13.0 what should do?

Please keep in mind that supporting older versions of the framework and language is not ideal because we can not see the new additional features and if the Flutter team removes deprecated APIs, it can cause problems for us because we still supporting an older version that had the API before it was deprecated, while also needing to support a newer version that no longer has the API.

If there is anything that I need to explain more, please let me know and I will be more than happy to provide additional details.