Refactor Permission Handling for Improved Readability

[michaelnabil230]

This PR introduces a new style for checking permission status.

Before:

Future<bool> askPermission() async {
  PermissionStatus status = await Permission.contacts.request();
  if (status.isDenied) {
    // Your code
  } else if (status.isGranted) {
    // Your code
  } else if (status.isRestricted) {
    // Your code
  }
}

After:

Future<bool> askPermission() async {
  await Permission.contacts
    .onDeniedCallback(() {
      // Your code
    })
    .onGrantedCallback(() {
      // Your code
    })
    .onRestrictedCallback(() {
      // Your code
    })
    .request();
}

In this updated code, the permission status checks have been replaced with a more concise style that leverages the PermissionCallbacks extension. This change simplifies the code and makes it more readable.

Pre-launch Checklist

• I made sure the project builds.
• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or this PR is does not need version changes.
• I updated CHANGELOG.md to add a description of the change.
• I updated/added relevant documentation (doc comments with ///).
• I rebased onto main.
• I added new tests to check the change I am making, or this PR does not need tests.
• I made sure all existing and new tests are passing.
• I ran dart format . and committed any changes.
• I ran flutter analyze and fixed any errors.

[codecov]

Codecov Report

Attention: 10 lines in your changes are missing coverage. Please review.

Files	Coverage Δ
permission_handler/lib/permission_handler.dart	71.42% <47.36%> (-28.58%)	⬇️

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[mvanbeusekom]

Hi @michaelnabil230,

This is a really interesting addition that we would love to support. I have two requests that I hope you could help update:

1. The different callbacks currently accept a function of type VoidCallback, I can imagine that some developers would like to run asynchronous tasks in side the callback (e.g. fetching a location once location permission is granted). I think it would be beneficial to update these callbacks to support a Future<void> (or possible a FutureOr<void>) method.
2. With the current changes there are two methods to start the permission request, request and ask. I think this might lead to confusion as it will be possible to register callbacks and then use request which doesn't use the registered callbacks. Since this is not a breaking change, why not add the callbacks to the current PermissionAction extension and call them from the request method?

[michaelnabil230]

Hi @mvanbeusekom

Thank you for your instruction.
Now, you have the opportunity to merge the PR so that everyone can reap the benefits of this feature.

[mvanbeusekom]

Hi @michaelnabil230,

I have noticed one more issue that I feel should be addressed.

[michaelnabil230]

Hi @mvanbeusekom

Thanks for the update! It's awesome to hear that the code is ready to merge. Let's proceed with the merging process.

[mvanbeusekom]

LGTM, thank you for this contribution.

P.S. maybe you could create another PR updating the documentation and explain this alternative route, so people are informed about this new feature.