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[local_auth] Suggestion for changes in error handling for LocalAuthentication().authenticate() #151513

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flutter/packages
#9981
Closed
[local_auth] Suggestion for changes in error handling for LocalAuthentication().authenticate()#151513
flutter/packages
#9981
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stuartmorgan-g
Labels
P2Important issues not at the top of the work listc: proposalA detailed proposal for a change to Flutterp: local_authPlugin for local authentificationpackageflutter/packages repository. See also p: labels.platform-iosiOS applications specificallyplatform-macosBuilding on or for macOS specificallyr: fixedIssue is closed as already fixed in a newer versionteam-iosOwned by iOS platform teamtriaged-iosTriaged by iOS platform team

Description

@TakuyaHida
TakuyaHida
opened on Jul 10, 2024

Use case

I'd like to suggest some changes to the error handling for the biometric authentication features provided by the local_auth library.
Currently, there are some differences in how errors are handled on iOS and Android.
I'm particularly focused on one specific situation on iOS: when iOS biometric authentication is voluntarily cancelled by the user.

Proposal

  • For cases when iOS biometric authentication is voluntarily cancelled by the user:

Currently, when a user voluntarily cancels the iOS biometric authentication, a PlatformException with error PlatformException(NotAvailable, Authentication canceled., com.apple.LocalAuthentication, null) is returned on Flutter's end. 

Simulator Screenshot - iPhone SE (3rd generation) - 2024-07-10 at 11 45 40

This PlatformException is indistinguishable from the PlatformException(NotAvailable, Authentication failure., com.apple.LocalAuthentication, null) returned when biometric authentication fails consecutively.
This makes it difficult to properly handle each exception.

However, on Android, when a user voluntarily cancels the authentication, the return value of LocalAuthentication().authenticate() is false.
Therefore, to make it easier to differentiate between the two exceptions, I propose that for voluntarily cancelled iOS biometric authentication, like Android, the return value of LocalAuthentication().authenticate() should be false.
I believe that this can be achieved by adding kLAErrorUserCancel to the iOS source code.

I believe that the issue could be resolved by writing a code as follows.
スクリーンショット 2024-07-09 18 57 11

Activity

  1. danagbemava-nc
    added
    in triagePresently being triaged by the triage team
    platform-iosiOS applications specifically
    platform-macosBuilding on or for macOS specifically
    p: local_authPlugin for local authentification
    packageflutter/packages repository. See also p: labels.
    c: proposalA detailed proposal for a change to Flutter
    fyi-ecosystemFor the attention of Ecosystem team
    team-iosOwned by iOS platform team
    and removed
    in triagePresently being triaged by the triage team
    on Jul 10, 2024
  2. stuartmorgan-g
    changed the title [-]local_auth: Suggestion for changes in error handling for LocalAuthentication().authenticate()[/-] [+][local_auth] Suggestion for changes in error handling for LocalAuthentication().authenticate()[/+] on Jul 16, 2024
  3. stuartmorgan-g
    added
    triaged-ecosystemTriaged by Ecosystem team
    on Jul 16, 2024

  4. stuartmorgan-g commented on Jul 16, 2024

    @stuartmorgan-g
    stuartmorgan-g
    on Jul 16, 2024
    Contributor

    In general we want to unify error handling across all platforms in our plugins (tracking issue for local_auth), which is a large project, but this looks like a case where we could incrementally make this specific change without a breaking change, so would be good to do in the short term.

  5. flutter-triage-bot
    removed
    fyi-ecosystemFor the attention of Ecosystem team
    triaged-ecosystemTriaged by Ecosystem team
    on Jul 16, 2024
  6. hellohuanlin
    added
    P2Important issues not at the top of the work list
    triaged-iosTriaged by iOS platform team
    on Jul 31, 2024
  7. stuartmorgan-g
    self-assigned this
    on Sep 4, 2025
  8. auto-submit
    closed this as completedin packages#9981on Oct 16, 2025
  9. pull
    added a commit that references this issue on Oct 16, 2025

    [local_auth] Adopt structured errors, and remove `useErrorDialogs` (f…

    61b3c54
  10. danagbemava-nc
    added
    r: fixedIssue is closed as already fixed in a newer version
    on Oct 17, 2025

  11. github-actions commented on Oct 31, 2025

    @github-actions
    github-actionsbot
    on Oct 31, 2025 – with GitHub Actions

    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.

  12. github-actions
    locked as resolved and limited conversation to collaborators on Oct 31, 2025
  13. creatorpiyush
    added a commit that references this issue on Jun 10, 2026

    [local_auth] Adopt structured errors, and remove `useErrorDialogs` (f…

    aaf9449
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P2Important issues not at the top of the work listc: proposalA detailed proposal for a change to Flutterp: local_authPlugin for local authentificationpackageflutter/packages repository. See also p: labels.platform-iosiOS applications specificallyplatform-macosBuilding on or for macOS specificallyr: fixedIssue is closed as already fixed in a newer versionteam-iosOwned by iOS platform teamtriaged-iosTriaged by iOS platform team

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