DBus: Receive singal and get wifi SSID

dbus-wifi-connect.js

import DBus from 'dbus'
import Promise from 'bluebird'

const dbus = new DBus()

const bus = dbus.getBus('system')

const NM_SERVICE = 'org.freedesktop.NetworkManager'
const NM_OBJECT = '/org/freedesktop/NetworkManager'
const NM_INTERFACE = NM_SERVICE
const NM_ACTIVE_CONN_INTERFACE = 'org.freedesktop.NetworkManager.Connection.Active'

Promise.fromCallback(
  (cb) => bus.getInterface(NM_SERVICE, NM_OBJECT, NM_INTERFACE, cb)
).then((iface) => {
  // DBus interface doc: https://developer.gnome.org/NetworkManager/0.9/spec.html#org.freedesktop.NetworkManager
  return new Promise((resolve) => {
    const propChangeListener = ({ PrimaryConnection, PrimaryConnectionType = '', State = 0 }) => {
      if (PrimaryConnectionType.includes('wireless') && State === 70 /* NM_STATE_CONNECTED_GLOBAL: Conntected, with global network */) {
        iface.removeListener('PropertiesChanged', propChangeListener)
        // Get active connection's interface
        resolve(Promise.fromCallback(
          (cb) => bus.getInterface(NM_SERVICE, PrimaryConnection, NM_ACTIVE_CONN_INTERFACE, cb)
        ))
      }
    }
    // Listen to signal
    iface.on('PropertiesChanged', propChangeListener)
  })
}).then((iface) => {
  // doc: https://developer.gnome.org/NetworkManager/0.9/spec.html#org.freedesktop.NetworkManager.Connection.Active
  // Actually, prop `Id` is the connection config's name
  // But it is same as SSID by default
  return Promise.fromCallback(
    (cb) => iface.getProperty('Id', cb)
  )
}).then((ssid) => {
  console.log(`Connect to ${ssid}`)
}).catch((err) => {
  console.error(err)
})