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    @ledgerhq/react-native-hw-transport-ble

    5.49.0 • Public • Published

    Github, Ledger Devs Slack

    @ledgerhq/react-native-hw-transport-ble

    Ledger Hardware Wallet Bluetooth BLE transport for React Native.

    yarn add @ledgerhq/react-native-hw-transport-ble
    

    Pre-requisite

    Troubleshootings

    Bad BLE link between the Phone and the device

    It can sometimes happen that the phone have a broken link, it is in this case recommended to users to go to their phone settings and manually Forget the Nano X. There is at the moment no other ways: there is no programmatic way to unpair a bonded device but you can however have a button that opens that phone settings Bluetooth section.

    undefined is not a function(evaluating '\_iterator[typeof Symbol === "function"?Symbol.iterator:"@@iterator"]()')

    Read again our Pre-requisites, you must set up jsc-android, alternatively you can figure out what polyfills are required. https://github.com/facebook/react-native/issues/15902

    Minimal getting started

    @ledgerhq/react-native-hw-transport-ble works like any of our @ledgerhq/hw-transport libraries.

    The difference here is that the listen() is costy and you likely don't want to always scan for devices, you would better save a selected device as "known" to suggest it to user later.

    Important: you will also have to deal with specifics of Bluetooth BLE, for instance, you need to request the LOCATION permission on Android!

    Here is a gist of the most important parts required.

    Check for Bluetooth state

    import TransportBLE from "@ledgerhq/react-native-hw-transport-ble";
    
    const subscription = TransportBLE.observeState({
      next: e => syncWithUI(e.available),
      complete: () => {},
      error: () => {}
    });

    when Bluetooth is available we can continue to...

    Scan for devices

    const subscription = TransportBLE.listen({
      complete: () => {
        this.setState({ refreshing: false });
      },
      next: e => {
        if (e.type === "add") {
          const device = e.descriptor;
          addDeviceToTheUI(device);
        }
      },
      error: error => {
        this.setState({ error, refreshing: false });
      }
    });
    
    // NB we also recommend the use of RxJS, you can just wrap it like so:
    // Observable.create(TransportBLE.listen).subscribe({ ... })
    // In the future of ledgerjs, we might directly returns Observable.

    This is the basic idea, obviously you need to call this code in your logic and implement addDeviceToTheUI(device).

    In that device object, you can typically use two fields:

    • device.id: a unique identifier of the device that can later be given to TransportBLE.open(id)
    • device.name: the name of the device (e.g. NanoX A4F5)

    With this device we can now...

    Connect to known device

    const transport = await TransportBLE.open(device);
    // OR
    const transport = await TransportBLE.open(deviceId); // deviceId can come from persisted state. It's unique per device

    and now we can just use the transport like any other Ledger transport!

    API

    Table of Contents

    BluetoothTransport

    Extends Transport

    react-native bluetooth BLE implementation

    Parameters

    • device Device
    • writeCharacteristic Characteristic
    • notifyObservable Observable<Buffer>
    • deviceModel DeviceModel

    Examples

    import BluetoothTransport from "@ledgerhq/react-native-hw-transport-ble";

    exchange

    communicate with a BLE transport

    Parameters

    Returns Promise<Buffer>

    isSupported

    Returns Promise<boolean>

    setLogLevel

    Parameters
    • level any

    observeState

    TODO could add this concept in all transports observe event with { available: bool, string } // available is generic, type is specific an event is emit once and then listened

    Parameters
    • observer any

    listen

    Scan for bluetooth Ledger devices

    Parameters
    • observer any

    open

    Open a BLE transport

    Parameters
    • deviceOrId any

    disconnect

    Globally disconnect a BLE device by its ID

    Parameters
    • id any

    Install

    npm i @ledgerhq/react-native-hw-transport-ble

    DownloadsWeekly Downloads

    67

    Version

    5.49.0

    License

    Apache-2.0

    Unpacked Size

    164 kB

    Total Files

    47

    Last publish

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