"Exploring the world of Ionic 2: uncovering its public variables

I'm facing an issue with Ionic 2, specifically with Angular. My concern revolves around a variable called "isConnected". I am unable to access it from an internal function within a function as it gives me an error saying "can't define property of undefined". How can I successfully access my variable "isConnected" from an internal function? I attempted to use this: BleProvider.prototype.isConnected but to no avail. Could someone kindly explain to me how to make this work?

export class BleProvider {

 public isConnected = false;
 public mDevice;

 constructor(public http: Http) {}

 connectToDevice(device){
  console.log('Connecting to device...');

  this.mDevice = device;
  setTimeout(
   ble.connectToDevice(
    device,
    onConnected,
    onDisconnected,
    onConnectError),
   500);

  function onConnected(device) {
    console.log("Connected to device: " + device.name);
    this.isConnected = true;
    console.log("isConnected variable status: " + this.isConnected);
  }
  function onDisconnected(device) {
    console.log('Disconnected from device: ' + device.name);
  }
  function onConnectError(error) {
    console.log('Connect error: ' + error);
  }
}

Answer №1

If you're looking to optimize your code, consider implementing arrow functions for improved performance:

export class BluetoothProvider {

    public isConnected = false;
    public device;

    constructor(public http: Http) { }

    connectToDevice(device) {
        console.log('Establishing connection with device...');

        this.device = device;

        // Enhance callbacks using arrow functions () => {...}
        let onConnected = (device) => {
                console.log("Device connected: " + device.name);
                this.isConnected = true;
                console.log("Connection status: " + this.isConnected);
            },
            onDisconnected = (device) => {
                console.log('Device disconnected: ' + device.name);
            },
            onConnectError = (error) => {
                console.log('Connection error: ' + error);
            }

        // Utilize arrow functions in setTimeout as well! :)
        setTimeout(() => {
            ble.connectToDevice(device, onConnected, onDisconnected, onConnectError);
        }, 500);

    }
}

Instead of a traditional function, arrow functions maintain the original context of this within your component instance, ensuring consistency with properties like isConnected.

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