get-devices.js

function populateBluetoothDevices() {
  const devicesSelect = document.querySelector('#devicesSelect');
  log('Getting existing permitted Bluetooth devices...');
  navigator.bluetooth.getDevices()
  .then(devices => {
    log('> Got ' + devices.length + ' Bluetooth devices.');
    devicesSelect.textContent = '';
    for (const device of devices) {
      const option = document.createElement('option');
      option.value = device.id;
      option.textContent = device.name;
      devicesSelect.appendChild(option);
    }
  })
  .catch(error => {
    log('Argh! ' + error);
  });
}

function onRequestBluetoothDeviceButtonClick() {
  log('Requesting any Bluetooth device...');
  navigator.bluetooth.requestDevice({
 // filters: [...] <- Prefer filters to save energy & show relevant devices.
    acceptAllDevices: true
  })
  .then(device => {
    log('> Requested ' + device.name + ' (' + device.id + ')');
    populateBluetoothDevices();
  })
  .catch(error => {
    log('Argh! ' + error);
  });
}

function onForgetBluetoothDeviceButtonClick() {
  navigator.bluetooth.getDevices()
  .then(devices => {
    const deviceIdToForget = document.querySelector('#devicesSelect').value;
    const device = devices.find((device) => device.id == deviceIdToForget);
    if (!device) {
      throw new Error('No Bluetooth device to forget');
    }
    log('Forgetting ' + device.name + 'Bluetooth device...');
    return device.forget();
  })
  .then(() => {
    log('  > Bluetooth device has been forgotten.');
    populateBluetoothDevices();
  })
  .catch(error => {
    log('Argh! ' + error);
  });
}

window.onload = () => {
  populateBluetoothDevices();
};