[Help]: Exception handling

[enseitankad0]

Requirements

• [X] I've looked at the README 'Common Problems' section

Have you checked this problem on the example app?

Yes

FlutterBluePlus Version

1.31.19

Flutter Version

3.16.0

What OS?

macOS

OS Version

14.1.1

Bluetooth Module

Norfic NRF52840

What is your problem?

I want to catch all exception and map them into a well defined classes. E.g

If I'm connecting to device id which does not exist I can check for:

e is PlatformException
e.code == 'connect'
e.message?.contains('is not a valid Bluetooth address')

and based on those rules I can return DeviceNotFoundError

I can also check platform and code of FlutterBluePlusException

e is FlutterBluePlusException
e.platform == ErrorPlatform.apple
e.code == 15

and base on it determine InsufficientEncryptionError

Question:

1. How to map similar exceptions into one common class to easily recognize them on UI? I know that all Exceptions thrown by FBP are very helpful in logs and in debug, but what if I want to present more specific error to the user?

Logs

no logs

[chipweinberger]

I recommend you use your app like a normal user to determine which errors occur

then catch them and add nicer messages

most exceptions should never occur in normal usage

[chipweinberger]

I dont have a comprehensive list of errors because iOS and Android do not provide a full list of errors

but you can look online to try and find it. maybe there are some resources online

[chipweinberger]

for example, here is the documentation for connect on iOS

https://developer.apple.com/documentation/corebluetooth/cbcentralmanager/connect(_:options:)

notice: they do not list the errors that can be thrown

[enseitankad0]

Thank you for quick reply. Basically I'm migrating my project from Flutter Reactive Ble to FBP. Previously I could just read excpection's message and based on it I could determine e.g., wrong pairing (bonding) issue, if exception contains "Writing is not permitted".

Based on that, I could tell user to go to settings and to remove pairing manually. It was necessary because sometimes w/o this step, I couldn't reconnect to the device after the update on Nordic chip was performed.

The problem is, if I would receive the same effect I should check all possibilities (for Android and iOS) and based on that, return appropriate error.

[chipweinberger]

yes.

you do do the same thing with FBP

i dont understand the problem.

[enseitankad0]

So for this specific error I've mentioned, should I check whether e is FlutterBluePlusException + apple-code: 3 | Writing is not permitted. or android-code: 3 | GATT_WRITE_NOT_PERMITTED, and based on that, create my custom error?

Or the check should be done based on: e is PlatformException && e.code == 'writeCharacteristic ?

[chipweinberger]

up to you.

id probably check for e.function == 'writeCharacteristic and e.code == 3