Check out example codes for "ionic loading". It will help you in understanding the concepts better.

Code Example 1

import { Component } from '@angular/core';
import { LoadingController } from '@ionic/angular';

@Component({
  selector: 'loading-example',
  templateUrl: 'loading-example.html',
  styleUrls: ['./loading-example.css']
})
export class LoadingExample {
  constructor(public loadingController: LoadingController) {}

  async presentLoading() {
    const loading = await this.loadingController.create({
      message: 'Please wait...',
      duration: 2000
    });
    await loading.present();

    const { role, data } = await loading.onDidDismiss();
    console.log('Loading dismissed!');
  }

  async presentLoadingWithOptions() {
    const loading = await this.loadingController.create({
      spinner: null,
      duration: 5000,
      message: 'Click the backdrop to dismiss early...',
      translucent: true,
      cssClass: 'custom-class custom-loading',
      backdropDismiss: true
    });
    await loading.present();

    const { role, data } = await loading.onDidDismiss();
    console.log('Loading dismissed with role:', role);
  }
}

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