How to use

AlertController

in

ionic-angular

login() {
  let loading = this.loadingCtrl.create({
   content: "Please wait..."
  });
  loading.present();
  this.loginService.login(this.username, this.password).subscribe(
   data => {
    // this.statusBar.backgroundColorByHexString("#25312C")
    this.provider.token = data['token'];
    localStorage.setItem('token', this.provider.token);
    this.provider.userData = jwtDecode( data['token']);
    console.log(this.provider.userData)
    this.navCtrl.push(TabsPage);
    loading.dismiss();
   },
   error => {
    console.log(error)
    let alert = this.alertCtrl.create({
     title: "Alert!",
     subTitle: "OOOOPS... Something Went Wrong",
     buttons: ["Dismiss"]
    });
    loading.dismiss();
    alert.present();
   }
  );
 }

data => {
 console.log(data);
 let alert = this.alertCtrl.create({
  title: "Alert!",
  subTitle: "Hi There! You have Sucessfully Signed Up!",
},
error => {
 let alert = this.alertCtrl.create({
  title: "Alert!",
  subTitle: "OOOOPS... Something Went Wrong",

   let alert = this.alertCtrl.create({
    title: "Alert!",
    subTitle: "OOOOPS... No flights found!",
   let alert = this.alertCtrl.create({
    title: "Alert!",
    subTitle: "OOOOPS... Something Went Wrong",
let alert = this.alertCtrl.create({
 title: "Alert!",
 subTitle: "Please enter all information",

let alert = this.alertCtrl.create({
 title: "Confirm Booking",
 message: "Are you sure, you want to book this flight?",
      data => {
       console.log("booked flight", data);
       let alert2 = this.alertCtrl.create({
        title: "Success!",
        subTitle:
      },
      error => {
       let alert3 = this.alertCtrl.create({
        title: "Alert!",
        subTitle:

checkin(bookingid, userid) {
  let alert = this.alertCtrl.create({
   title: "Confirm Checkin",
   message: "Do you want to checkin?",
         .subscribe(
          data2 => {
           let alert = this.alertCtrl.create({
            title: "Success",
            subTitle: "Congrats You Have Successfully Checkedin",
          },
          error => {
           let alert = this.alertCtrl.create({
            title: "OOOPS... Something Went Wrong",
            subTitle: "Please try again later",

let alert = this.alertCtrl.create({
 title: "Alert!",
 subTitle: "OOOOPS... No flights found!",
let alert = this.alertCtrl.create({
 title: "Alert!",
 subTitle: "OOOOPS... Something Went Wrong",

    let alert3 = this.alertCtrl.create({
     title: "Alert!",
     subTitle:
let alert = this.alertCtrl.create({
 title: "Confirm Booking",
 message: "Are you sure, you want to book this flight?",
      data => {
       console.log("booked flight", data);
       let alert2 = this.alertCtrl.create({
        title: "Success!",
        subTitle:
      },
      error => {
       let alert3 = this.alertCtrl.create({
        title: "Alert!",
        subTitle: