alert.service.ts

import {Injectable} from '@angular/core';
import {ToastyService, ToastyConfig, ToastyComponent, ToastOptions, ToastData} from 'ng2-toasty';
import {Subject, Observable, Subscription} from 'rxjs/Rx';

@Injectable()
export class AlertService {
    
    getTitle(num: number): string {
        return 'Countdown: ' + num;
    }

    getMessage(num: number): string {
        return 'Seconds left: ' + num;
    }
    
    constructor(private toastyService:ToastyService) { }
    
    addToast() {
        let interval = 1000;
        let timeout = 5000;
        let seconds = timeout / 1000;
        let subscription: Subscription;
        
        let toastOptions: ToastOptions = {
            title: this.getTitle(seconds),
            msg: this.getMessage(seconds),
            showClose: true,
            timeout: timeout,
            onAdd: (toast: ToastData) => {
                console.log('Toast ' + toast.id + ' has been added!');
                // Run the timer with 1 second iterval
                let observable = Observable.interval(interval).take(seconds);
                // Start listen seconds beat
                subscription = observable.subscribe((count: number) => {
                    // Update title of toast
                    toast.title = this.getTitle(seconds - count - 1);
                    // Update message of toast
                    toast.msg = this.getMessage(seconds - count - 1);
                });

            },
            onRemove: function(toast: ToastData) {
                console.log('Toast ' + toast.id + ' has been removed!');
                // Stop listenning
                subscription.unsubscribe();
            }
        };

        switch (this.options.type) {
            case 'default': this.toastyService.default(toastOptions); break;
            case 'info': this.toastyService.info(toastOptions); break;
            case 'success': this.toastyService.success(toastOptions); break;
            case 'wait': this.toastyService.wait(toastOptions); break;
            case 'error': this.toastyService.error(toastOptions); break;
            case 'warning': this.toastyService.warning(toastOptions); break;
        }
    }
}