Notification Manager to trigger the toast message

CmsNotificationManager.cs

using Sitecore.Events;
using Sitecore.Experiment.Notification.Models;
using Sitecore.Web.UI.Sheer;
using System;

public class CmsNotificationManager
{
	private static bool _initialized;

	private static readonly object globalLock = new object();

	public static void Initialize()
	{
		if (_initialized)
		{
			return;
		}

		lock (globalLock)
		{
			if (_initialized)
			{
				return;
			}

			try
			{
				Event.Subscribe("cms:notify", new EventHandler(CmsNotifier));
			}
			finally
			{
				_initialized = true;
			}
		}
	}

	private static void CmsNotifier(object sender, EventArgs args)
	{
		var parameters = Event.ExtractParameter<NotifierArgs>(args, 0);

		var message = string.Empty;

		switch (parameters.EventName)
		{
			case "package:end":
				{
					message = "The package installation has completed";

					break;
				}
			case "item:save":
				{
					message = "The item has been saved";

					break;
				}
		}

		var script = $"toastr.info('{message}')";

		SheerResponse.Eval(script);
	}
}