@ledgerhq/hw-transport implements the generic interface of a Ledger Hardware Wallet transport.
Type: {unsubscribe: function (): void}
unsubscribefunction (): void
Type: Object
type: add or remove event descriptor: a parameter that can be passed to open(descriptor) deviceModel: device info on the model (is it a nano s, nano x, ...) device: transport specific device info
Type: {type: ("add" | "remove"), descriptor: Descriptor, deviceModel: DeviceModel??, device: Device?}
type("add"|"remove")descriptorDescriptordeviceModelDeviceModel??deviceDevice?
Type: $ReadOnly<{next: function (event: Ev): any, error: function (e: any): any, complete: function (): any}>
Transport defines the generic interface to share between node/u2f impl A Descriptor is a parametric type that is up to be determined for the implementation. it can be for instance an ID, an file path, a URL,...
low level api to communicate with the device This method is for implementations to implement but should not be directly called. Instead, the recommanded way is to use send() method
Type: function (apdu: Buffer): Promise<Buffer>
apduthe data to send
Returns any a Promise of response data
set the "scramble key" for the next exchanges with the device. Each App can have a different scramble key and they internally will set it at instanciation.
Type: function (key: string): void
keythe scramble key
close the exchange with the device.
Type: function (): Promise<void>
Returns any a Promise that ends when the transport is closed.
Listen to an event on an instance of transport. Transport implementation can have specific events. Here is the common events:
"disconnect": triggered if Transport is disconnected
Stop listening to an event on an instance of transport.
Enable or not logs of the binary exchange
Set a timeout (in milliseconds) for the exchange call. Only some transport might implement it. (e.g. U2F)
exchangeTimeoutnumber
wrapper on top of exchange to simplify work of the implementation.
clanumberinsnumberp1numberp2numberdataBuffer (optional, defaultBuffer.alloc(0))statusListArray<number> is a list of accepted status code (shorts). [0x9000] by default (optional, default[StatusCodes.OK])
Returns Promise<Buffer> a Promise of response buffer
Statically check if a transport is supported on the user's platform/browser.
Type: function (): Promise<boolean>
List once all available descriptors. For a better granularity, checkout listen().
Type: function (): Promise<Array<Descriptor>>
TransportFoo.list().then(descriptors => ...)Returns any a promise of descriptors
Listen all device events for a given Transport. The method takes an Obverver of DescriptorEvent and returns a Subscription (according to Observable paradigm https://github.com/tc39/proposal-observable )
a DescriptorEvent is a { descriptor, type } object. type can be "add" or "remove" and descriptor is a value you can pass to open(descriptor).
each listen() call will first emit all potential device already connected and then will emit events can come over times,
for instance if you plug a USB device after listen() or a bluetooth device become discoverable.
Type: function (observer: Observer<DescriptorEvent<Descriptor>>): Subscription
observeris an object with a next, error and complete function (compatible with observer pattern)
const sub = TransportFoo.listen({
next: e => {
if (e.type==="add") {
sub.unsubscribe();
const transport = await TransportFoo.open(e.descriptor);
...
}
},
error: error => {},
complete: () => {}
})Returns any a Subscription object on which you can .unsubscribe() to stop listening descriptors.
attempt to create a Transport instance with potentially a descriptor.
Type: function (descriptor: Descriptor, timeout: number): Promise<Transport<Descriptor>>
descriptor: the descriptor to open the transport with.timeout: an optional timeout
TransportFoo.open(descriptor).then(transport => ...)Returns any a Promise of Transport instance
create() allows to open the first descriptor available or throw if there is none or if timeout is reached. This is a light helper, alternative to using listen() and open() (that you may need for any more advanced usecase)
TransportFoo.create().then(transport => ...)