B2G/Bluetooth/WebBluetooth-v2/BluetoothDevice

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Overview

BluetoothDevice provides information regarding a given remote bluetooth device.

Interfaces

BluetoothDevice

[CheckPermissions="bluetooth"]
interface BluetoothDevice: EventTarget
{
  readonly attribute DOMString address;
  readonly attribute BluetoothClassOfDevice cod;
  readonly attribute DOMString name;
  readonly attribute boolean paired;
  [Cached, Pure] readonly attribute sequence<DOMString> uuids;
  readonly attribute BluetoothDeviceType type;
  readonly attribute BluetoothGatt? gatt;

           attribute EventHandler onattributechanged;

  [NewObject, Throws] Promise<sequence<DOMString>> fetchUuids();
  [NewObject, Throws] Promise<BluetoothGatt> connectGatt(boolean aAutoConnect);
};

BluetoothDeviceType

enum BluetoothDeviceType
{
  "unknown",
  "classic",
  "le",
  "dual",
}

BluetoothDeviceAttribute

enum BluetoothDeviceAttribute
{
  "unknown",
  "cod",
  "name",
  "paired",
  "uuids"
}

Properties

address

Description
The address property provides the address of the device on the bluetooth micro-network.
Value type
DOMString
Default value
Empty string ("")
Sample
var address = device.address;

cod

Description
The cod property is a BluetoothClassOfDevice object that provides much information about the device's capabilities.
Value type
BluetoothClassOfDevice
Default value
A BluetoothClassOfDevice object whose attributes are default values.
Sample
var cod = device.cod;

var majorDeviceClass = cod.BluetoothMajorDeviceClass;
var majorServiceClass = cod.BluetoothMajorServiceClass;
var minorDeviceClass = cod.BluetoothMinorDeviceClass;

name

Description
The name property is the human readable name of the device.
Value type
DOMString
Default value
Empty string ("")
Sample
var name = device.name;

paired

Description
The paired property indicates whether this remote device is paired to current device's adapter (true) or not (false).
Value type
boolean
Default value
false
Sample
var paired = device.paired;

uuids

Description
[Cached, Pure]
The property stores the cached UUID list of services that the remote device provides. If applications require the up-to-date UUID list is required, call fetchUuids() to update this property. This property is marked with [Cached] because the same JS Array object is returned until a fetchUuids() call happens, and marked with [Pure] rather than [Constant] because uuids is updated once fetchUuids() executes.
Value type
sequence<DOMString>
Default value
An empty array (array with length = 0)
Sample
var uuids = device.uuids;

type

Description
The type property indicates the device type of the remote device.
Value type
BluetoothDeviceType
Default value
BluetoothDeviceType.unknown
Sample
var type = device.type;

gatt

Description
The gatt property is object used to conduct GATT client operations on this remote LE device. Applications have to call connectGatt() to update this property. This property must be null pointer for devices of type classic or unknown.
Value type
BluetoothGatt
Default value
Null pointer
Sample
var gatt = device.gatt;

Event Handlers

onattributechanged

Description
A handler to trigger when on of the remote device's properties has changed. Note access to the changed property in this event handler would get the updated value.
Paramter
aAttributeEvent
The event is a BluetoothAttributeEvent with property attrs that contains changed BluetoothDeviceAttributes.
Sample
device.onattributechanged = function onDeviceAttributeChanged(evt) {
  for (var i in evt.attrs) {
    switch (evt.attrs[i]) {
      case 'name':
        console.log("device name changed to", device.name);
        break;
      case 'paired':
        console.log("device paired changed to", device.paired);
        break;
      default:
        break;
    }
  }
}

Methods

fetchUuids()

Description
The method fetches the up-to-date UUID list of services that the device provides. If the fetchUuids operation succeeds, an onattributechanged would be triggered right before the Promise is resolved to indicate device.uuids has changed.
Return
A Promise to indicate whether the operation is resolved or rejected. If the Promise is resolved, it returns a DOMString array representing the updated list of UUIDs.
Sample
device.fetchUuids().then ( function onResolve(uuids) {
  console.log("Resolved with uuids:");
  for (var i = 0; i < uuids.length; i++) {   
    console.log("uuid", i, "is", uuids[i]);
  }
}, function onReject(aReason) {
  console.log("Rejected with this reason: " + aReason);
});

connectGatt(boolean aAutoConnect)

Description
The method does three things at once:
1) connects to remote LE device,
2) discovers services offered by a remote LE device as well as their characteristics and descriptors, and then
3) creates a BluetoothGatt object for the remote LE device and assigns it to property gatt.
Parameter
aAutoConnect
Whether to directly connect to the remote device (false) or to automatically connect as soon as the remote device becomes available (true).
Return
A Promise to indicate whether the operation is resolved or rejected. If the Promise is resolved, it returns a BluetoothGatt object whose property connectionState is connected. The promise is rejected if 1) the device is not of type le or dual, 2) connection to remote LE device fails, or 3) creation of BluetoothGatt object fails.
Sample
var autoConnect = false;

device.connectGatt(autoConnect).then ( function onResolve(gatt) {
  // gatt.connectionState is connected.
  console.log("Resolved with gatt. Connection state:", gatt.connectionState);
}, function onReject(aReason) {
  console.log("Rejected with this reason: " + aReason);
});

See also

Retrieved from "https://wiki.allizom.org/index.php?title=B2G/Bluetooth/WebBluetooth-v2/BluetoothDevice&oldid=1030745"