@abandonware/noble/lib/noble.js

A Node.js BLE (Bluetooth Low Energy) central library.

const debug = require('debug')('noble');

const events = require('events');
const util = require('util');

const Peripheral = require('./peripheral');
const Service = require('./service');
const Characteristic = require('./characteristic');
const Descriptor = require('./descriptor');

function Noble (bindings) {
  this.initialized = false;

  this.address = 'unknown';
  this._state = 'unknown';
  this._bindings = bindings;
  this._peripherals = {};
  this._services = {};
  this._characteristics = {};
  this._descriptors = {};
  this._discoveredPeripheralUUids = {};

  this._bindings.on('stateChange', this.onStateChange.bind(this));
  this._bindings.on('addressChange', this.onAddressChange.bind(this));
  this._bindings.on('scanParametersSet', this.onScanParametersSet.bind(this));
  this._bindings.on('scanStart', this.onScanStart.bind(this));
  this._bindings.on('scanStop', this.onScanStop.bind(this));
  this._bindings.on('discover', this.onDiscover.bind(this));
  this._bindings.on('connect', this.onConnect.bind(this));
  this._bindings.on('disconnect', this.onDisconnect.bind(this));
  this._bindings.on('rssiUpdate', this.onRssiUpdate.bind(this));
  this._bindings.on('servicesDiscover', this.onServicesDiscover.bind(this));
  this._bindings.on('servicesDiscovered', this.onServicesDiscovered.bind(this));
  this._bindings.on('includedServicesDiscover', this.onIncludedServicesDiscover.bind(this));
  this._bindings.on('characteristicsDiscover', this.onCharacteristicsDiscover.bind(this));
  this._bindings.on('characteristicsDiscovered', this.onCharacteristicsDiscovered.bind(this));
  this._bindings.on('read', this.onRead.bind(this));
  this._bindings.on('write', this.onWrite.bind(this));
  this._bindings.on('broadcast', this.onBroadcast.bind(this));
  this._bindings.on('notify', this.onNotify.bind(this));
  this._bindings.on('descriptorsDiscover', this.onDescriptorsDiscover.bind(this));
  this._bindings.on('valueRead', this.onValueRead.bind(this));
  this._bindings.on('valueWrite', this.onValueWrite.bind(this));
  this._bindings.on('handleRead', this.onHandleRead.bind(this));
  this._bindings.on('handleWrite', this.onHandleWrite.bind(this));
  this._bindings.on('handleNotify', this.onHandleNotify.bind(this));
  this._bindings.on('onMtu', this.onMtu.bind(this));

  this.on('warning', (message) => {
    if (this.listeners('warning').length === 1) {
      console.warn(`noble: ${message}`);
    }
  });

  // lazy init bindings on first new listener, should be on stateChange
  this.on('newListener', (event) => {
    if (event === 'stateChange' && !this.initialized) {
      this.initialized = true;

      process.nextTick(() => {
        try {
          this._bindings.init();
        } catch (error) {
          this.emit('warning', 'Initialization of USB device failed: ' + error.message);
        }
      });
    }
  });

  // or lazy init bindings if someone attempts to get state first
  Object.defineProperties(this, {
    state: {
      get: function () {
        if (!this.initialized) {
          this.initialized = true;

          this._bindings.init();
        }
        return this._state;
      }
    }
  });
}

util.inherits(Noble, events.EventEmitter);

Noble.prototype.onStateChange = function (state) {
  debug(`stateChange ${state}`);

  this._state = state;

  this.emit('stateChange', state);
};

Noble.prototype.onAddressChange = function (address) {
  debug(`addressChange ${address}`);

  this.address = address;
};

Noble.prototype.setScanParameters = function (interval, window, callback) {
  if (callback) {
    this.once('scanParametersSet', callback);
  }
  this._bindings.setScanParameters(interval, window);
};

Noble.prototype.onScanParametersSet = function () {
  debug('scanParametersSet');
  this.emit('scanParametersSet');
};

const startScanning = function (serviceUuids, allowDuplicates, callback) {
  if (typeof serviceUuids === 'function') {
    this.emit('warning', 'calling startScanning(callback) is deprecated');
  }

  if (typeof allowDuplicates === 'function') {
    this.emit('warning', 'calling startScanning(serviceUuids, callback) is deprecated');
  }

  const scan = function (state) {
    if (state !== 'poweredOn') {
      const error = new Error(`Could not start scanning, state is ${state} (not poweredOn)`);

      if (typeof callback === 'function') {
        callback(error);
      } else {
        throw error;
      }
    } else {
      if (callback) {
        this.once('scanStart', filterDuplicates => {
          callback(null, filterDuplicates);
        });
      }

      this._discoveredPeripheralUUids = {};
      this._allowDuplicates = allowDuplicates;

      this._bindings.startScanning(serviceUuids, allowDuplicates);
    }
  };

  // if bindings still not init, do it now
  if (!this.initialized) {
    this.initialized = true;

    this._bindings.init();

    this.once('stateChange', scan.bind(this));
  } else {
    scan.call(this, this._state);
  }
};

Noble.prototype.startScanning = startScanning;
Noble.prototype.startScanningAsync = function (serviceUUIDs, allowDuplicates) {
  return util.promisify((callback) => this.startScanning(serviceUUIDs, allowDuplicates, callback))();
};

Noble.prototype.onScanStart = function (filterDuplicates) {
  debug('scanStart');
  this.emit('scanStart', filterDuplicates);
};

const stopScanning = function (callback) {
  if (callback) {
    this.once('scanStop', callback);
  }
  if (this._bindings && this.initialized) {
    this._bindings.stopScanning();
  }
};

Noble.prototype.stopScanning = stopScanning;
Noble.prototype.stopScanningAsync = util.promisify(stopScanning);

Noble.prototype.onScanStop = function () {
  debug('scanStop');
  this.emit('scanStop');
};

Noble.prototype.reset = function () {
  this._bindings.reset();
};

Noble.prototype.onDiscover = function (uuid, address, addressType, connectable, advertisement, rssi, scannable) {
  let peripheral = this._peripherals[uuid];

  if (!peripheral) {
    peripheral = new Peripheral(this, uuid, address, addressType, connectable, advertisement, rssi, scannable);

    this._peripherals[uuid] = peripheral;
    this._services[uuid] = {};
    this._characteristics[uuid] = {};
    this._descriptors[uuid] = {};
  } else {
    // "or" the advertisment data with existing
    for (const i in advertisement) {
      if (advertisement[i] !== undefined) {
        peripheral.advertisement[i] = advertisement[i];
      }
    }

    peripheral.connectable = connectable;
    peripheral.scannable = scannable;
    peripheral.rssi = rssi;
  }

  const previouslyDiscoverd = this._discoveredPeripheralUUids[uuid] === true;

  if (!previouslyDiscoverd) {
    this._discoveredPeripheralUUids[uuid] = true;
  }

  if (this._allowDuplicates || !previouslyDiscoverd || (!scannable && !connectable)) {
    this.emit('discover', peripheral);
  }
};

Noble.prototype.connect = function (peripheralUuid, parameters) {
  this._bindings.connect(peripheralUuid, parameters);
};

Noble.prototype.onConnect = function (peripheralUuid, error) {
  const peripheral = this._peripherals[peripheralUuid];

  if (peripheral) {
    peripheral.state = error ? 'error' : 'connected';
    peripheral.emit('connect', error);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid} connected!`);
  }
};

Noble.prototype.cancelConnect = function (peripheralUuid, parameters) {
  this._bindings.cancelConnect(peripheralUuid, parameters);
};

Noble.prototype.disconnect = function (peripheralUuid) {
  this._bindings.disconnect(peripheralUuid);
};

Noble.prototype.onDisconnect = function (peripheralUuid, reason) {
  const peripheral = this._peripherals[peripheralUuid];

  if (peripheral) {
    peripheral.state = 'disconnected';
    peripheral.emit('disconnect', reason);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid} disconnected!`);
  }
};

Noble.prototype.updateRssi = function (peripheralUuid) {
  this._bindings.updateRssi(peripheralUuid);
};

Noble.prototype.onRssiUpdate = function (peripheralUuid, rssi) {
  const peripheral = this._peripherals[peripheralUuid];

  if (peripheral) {
    peripheral.rssi = rssi;

    peripheral.emit('rssiUpdate', rssi);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid} RSSI update!`);
  }
};

/// add an array of service objects (as retrieved via the servicesDiscovered event)
Noble.prototype.addServices = function (peripheralUuid, services) {
  const servObjs = [];

  for (let i = 0; i < services.length; i++) {
    const o = this.addService(peripheralUuid, services[i]);
    servObjs.push(o);
  }
  return servObjs;
};

/// service is a ServiceObject { uuid, startHandle, endHandle,..}
Noble.prototype.addService = function (peripheralUuid, service) {
  const peripheral = this._peripherals[peripheralUuid];

  // pass on to lower layers (gatt)
  if (this._bindings.addService) {
    this._bindings.addService(peripheralUuid, service);
  }

  if (!peripheral.services) {
    peripheral.services = [];
  }
  // allocate internal service object and return
  const serv = new Service(this, peripheralUuid, service.uuid);

  this._services[peripheralUuid][service.uuid] = serv;
  this._characteristics[peripheralUuid][service.uuid] = {};
  this._descriptors[peripheralUuid][service.uuid] = {};

  peripheral.services.push(serv);

  return serv;
};

/// callback receiving a list of service objects from the gatt layer
Noble.prototype.onServicesDiscovered = function (peripheralUuid, services) {
  const peripheral = this._peripherals[peripheralUuid];

  if (peripheral) { peripheral.emit('servicesDiscovered', peripheral, services); } // pass on to higher layers
};

Noble.prototype.discoverServices = function (peripheralUuid, uuids) {
  this._bindings.discoverServices(peripheralUuid, uuids);
};

Noble.prototype.onServicesDiscover = function (peripheralUuid, serviceUuids) {
  const peripheral = this._peripherals[peripheralUuid];

  if (peripheral) {
    const services = [];

    for (let i = 0; i < serviceUuids.length; i++) {
      const serviceUuid = serviceUuids[i];
      const service = new Service(this, peripheralUuid, serviceUuid);

      this._services[peripheralUuid][serviceUuid] = service;
      this._characteristics[peripheralUuid][serviceUuid] = {};
      this._descriptors[peripheralUuid][serviceUuid] = {};

      services.push(service);
    }

    peripheral.services = services;

    peripheral.emit('servicesDiscover', services);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid} services discover!`);
  }
};

Noble.prototype.discoverIncludedServices = function (peripheralUuid, serviceUuid, serviceUuids) {
  this._bindings.discoverIncludedServices(peripheralUuid, serviceUuid, serviceUuids);
};

Noble.prototype.onIncludedServicesDiscover = function (peripheralUuid, serviceUuid, includedServiceUuids) {
  const service = this._services[peripheralUuid][serviceUuid];

  if (service) {
    service.includedServiceUuids = includedServiceUuids;

    service.emit('includedServicesDiscover', includedServiceUuids);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid}, ${serviceUuid} included services discover!`);
  }
};

/// add characteristics to the peripheral; returns an array of initialized Characteristics objects
Noble.prototype.addCharacteristics = function (peripheralUuid, serviceUuid, characteristics) {
  // first, initialize gatt layer:
  if (this._bindings.addCharacteristics) {
    this._bindings.addCharacteristics(peripheralUuid, serviceUuid, characteristics);
  }

  const service = this._services[peripheralUuid][serviceUuid];
  if (!service) {
    this.emit('warning', `unknown service ${peripheralUuid}, ${serviceUuid} characteristics discover!`);
    return;
  }

  const characteristics_ = [];
  for (let i = 0; i < characteristics.length; i++) {
    const characteristicUuid = characteristics[i].uuid;

    const characteristic = new Characteristic(
      this,
      peripheralUuid,
      serviceUuid,
      characteristicUuid,
      characteristics[i].properties
    );

    this._characteristics[peripheralUuid][serviceUuid][characteristicUuid] = characteristic;
    this._descriptors[peripheralUuid][serviceUuid][characteristicUuid] = {};

    characteristics_.push(characteristic);
  }
  service.characteristics = characteristics_;
  return characteristics_;
};

Noble.prototype.onCharacteristicsDiscovered = function (peripheralUuid, serviceUuid, characteristics) {
  const service = this._services[peripheralUuid][serviceUuid];

  service.emit('characteristicsDiscovered', characteristics);
};

Noble.prototype.discoverCharacteristics = function (peripheralUuid, serviceUuid, characteristicUuids) {
  this._bindings.discoverCharacteristics(peripheralUuid, serviceUuid, characteristicUuids);
};

Noble.prototype.onCharacteristicsDiscover = function (peripheralUuid, serviceUuid, characteristics) {
  const service = this._services[peripheralUuid][serviceUuid];

  if (service) {
    const characteristics_ = [];

    for (let i = 0; i < characteristics.length; i++) {
      const characteristicUuid = characteristics[i].uuid;

      const characteristic = new Characteristic(
        this,
        peripheralUuid,
        serviceUuid,
        characteristicUuid,
        characteristics[i].properties
      );

      this._characteristics[peripheralUuid][serviceUuid][characteristicUuid] = characteristic;
      this._descriptors[peripheralUuid][serviceUuid][characteristicUuid] = {};

      characteristics_.push(characteristic);
    }

    service.characteristics = characteristics_;

    service.emit('characteristicsDiscover', characteristics_);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid}, ${serviceUuid} characteristics discover!`);
  }
};

Noble.prototype.read = function (peripheralUuid, serviceUuid, characteristicUuid) {
  this._bindings.read(peripheralUuid, serviceUuid, characteristicUuid);
};

Noble.prototype.onRead = function (peripheralUuid, serviceUuid, characteristicUuid, data, isNotification) {
  const characteristic = this._characteristics[peripheralUuid][serviceUuid][characteristicUuid];

  if (characteristic) {
    characteristic.emit('data', data, isNotification);

    characteristic.emit('read', data, isNotification); // for backwards compatbility
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid}, ${serviceUuid}, ${characteristicUuid} read!`);
  }
};

Noble.prototype.write = function (peripheralUuid, serviceUuid, characteristicUuid, data, withoutResponse) {
  this._bindings.write(peripheralUuid, serviceUuid, characteristicUuid, data, withoutResponse);
};

Noble.prototype.onWrite = function (peripheralUuid, serviceUuid, characteristicUuid) {
  const characteristic = this._characteristics[peripheralUuid][serviceUuid][characteristicUuid];

  if (characteristic) {
    characteristic.emit('write');
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid}, ${serviceUuid}, ${characteristicUuid} write!`);
  }
};

Noble.prototype.broadcast = function (peripheralUuid, serviceUuid, characteristicUuid, broadcast) {
  this._bindings.broadcast(peripheralUuid, serviceUuid, characteristicUuid, broadcast);
};

Noble.prototype.onBroadcast = function (peripheralUuid, serviceUuid, characteristicUuid, state) {
  const characteristic = this._characteristics[peripheralUuid][serviceUuid][characteristicUuid];

  if (characteristic) {
    characteristic.emit('broadcast', state);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid}, ${serviceUuid}, ${characteristicUuid} broadcast!`);
  }
};

Noble.prototype.notify = function (peripheralUuid, serviceUuid, characteristicUuid, notify) {
  this._bindings.notify(peripheralUuid, serviceUuid, characteristicUuid, notify);
};

Noble.prototype.onNotify = function (peripheralUuid, serviceUuid, characteristicUuid, state) {
  const characteristic = this._characteristics[peripheralUuid][serviceUuid][characteristicUuid];

  if (characteristic) {
    characteristic.emit('notify', state);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid}, ${serviceUuid}, ${characteristicUuid} notify!`);
  }
};

Noble.prototype.discoverDescriptors = function (peripheralUuid, serviceUuid, characteristicUuid) {
  this._bindings.discoverDescriptors(peripheralUuid, serviceUuid, characteristicUuid);
};

Noble.prototype.onDescriptorsDiscover = function (peripheralUuid, serviceUuid, characteristicUuid, descriptors) {
  const characteristic = this._characteristics[peripheralUuid][serviceUuid][characteristicUuid];

  if (characteristic) {
    const descriptors_ = [];

    for (let i = 0; i < descriptors.length; i++) {
      const descriptorUuid = descriptors[i];

      const descriptor = new Descriptor(
        this,
        peripheralUuid,
        serviceUuid,
        characteristicUuid,
        descriptorUuid
      );

      this._descriptors[peripheralUuid][serviceUuid][characteristicUuid][descriptorUuid] = descriptor;

      descriptors_.push(descriptor);
    }

    characteristic.descriptors = descriptors_;

    characteristic.emit('descriptorsDiscover', descriptors_);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid}, ${serviceUuid}, ${characteristicUuid} descriptors discover!`);
  }
};

Noble.prototype.readValue = function (peripheralUuid, serviceUuid, characteristicUuid, descriptorUuid) {
  this._bindings.readValue(peripheralUuid, serviceUuid, characteristicUuid, descriptorUuid);
};

Noble.prototype.onValueRead = function (peripheralUuid, serviceUuid, characteristicUuid, descriptorUuid, data) {
  const descriptor = this._descriptors[peripheralUuid][serviceUuid][characteristicUuid][descriptorUuid];

  if (descriptor) {
    descriptor.emit('valueRead', data);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid}, ${serviceUuid}, ${characteristicUuid}, ${descriptorUuid} value read!`);
  }
};

Noble.prototype.writeValue = function (peripheralUuid, serviceUuid, characteristicUuid, descriptorUuid, data) {
  this._bindings.writeValue(peripheralUuid, serviceUuid, characteristicUuid, descriptorUuid, data);
};

Noble.prototype.onValueWrite = function (peripheralUuid, serviceUuid, characteristicUuid, descriptorUuid) {
  const descriptor = this._descriptors[peripheralUuid][serviceUuid][characteristicUuid][descriptorUuid];

  if (descriptor) {
    descriptor.emit('valueWrite');
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid}, ${serviceUuid}, ${characteristicUuid}, ${descriptorUuid} value write!`);
  }
};

Noble.prototype.readHandle = function (peripheralUuid, handle) {
  this._bindings.readHandle(peripheralUuid, handle);
};

Noble.prototype.onHandleRead = function (peripheralUuid, handle, data) {
  const peripheral = this._peripherals[peripheralUuid];

  if (peripheral) {
    peripheral.emit(`handleRead${handle}`, data);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid} handle read!`);
  }
};

Noble.prototype.writeHandle = function (peripheralUuid, handle, data, withoutResponse) {
  this._bindings.writeHandle(peripheralUuid, handle, data, withoutResponse);
};

Noble.prototype.onHandleWrite = function (peripheralUuid, handle) {
  const peripheral = this._peripherals[peripheralUuid];

  if (peripheral) {
    peripheral.emit(`handleWrite${handle}`);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid} handle write!`);
  }
};

Noble.prototype.onHandleNotify = function (peripheralUuid, handle, data) {
  const peripheral = this._peripherals[peripheralUuid];

  if (peripheral) {
    peripheral.emit('handleNotify', handle, data);
  } else {
    this.emit('warning', `unknown peripheral ${peripheralUuid} handle notify!`);
  }
};

Noble.prototype.onMtu = function (peripheralUuid, mtu) {
  const peripheral = this._peripherals[peripheralUuid];
  if (peripheral && mtu) peripheral.mtu = mtu;
};

module.exports = Noble;