How to Create Alert Notifications with JavaScript

Introduction

In this post, I will explain how to display a message from Controller in View, using JavaScript alert MessageBox. The message sent from Controller to View will be displayed in JavaScript Alert MessageBox using the ViewBag Object.

Controller

First, we create a new project using Visual Studio. Choose Project template MVC. Now, we create Controller. Controller has two action methods, mentioned below:

Action method for handling GET operation.
Inside this Action method, only the view is returned.
Action method for handling POST operation.
This Action method handles the form submission and it accepts the value of the form element as a parameter.

The name value fetched from the Form collection and the current Server date and time is set to a ViewBag object named “Message”.

Controller Code

using System;  
using System.Collections.Generic;  
using System.Linq;  
using System.Web;  
using System.Web.Mvc;  
  
namespace AlertMessge.Controllers  
{  
    public class HomeController : Controller  
    {  
        public ActionResult Index()  
        {  
            return View();  
        }  
  
        [HttpPost]  
        public ActionResult  Index(string name)  
        {  
            ViewBag.Message = String.Format("Hello{0}.\\ncurrent Date and time:{1}", name, DateTime.Now.ToString());  
            return View();  
        }  
          
    }  
}

VIEW

The View consists of HTML form, which has been created using the Html.BeginForm method with the parameters, as mentioned below:

_ActionName_Name of the Action. In this case, the name is Index.
ControllerName Name of the Controller. In this case, the name is Home.
FormMethod It specifies the Form Method i.e. GET or POST. In this case it will be set to POST.

The Form consists of two elements i.e. a TextBox and a Submit Button.

The ViewBag object named Message is checked for NULL and if it is not NULL, the value of the object is displayed, using JavaScript alert MessageBox.

View Code

@{  
    Layout = null;  
}  
   
<!DOCTYPE html>  
   
<html>  
<head>  
    <meta name="viewport" content="width=device-width"/>  
    <title>Index</title>  
</head>  
<body>  
    @using (Html.BeginForm("Index", "Home", FormMethod.Post))  
    {  
        <input type="text" id="txtName" name="name"/>  
        <input type="submit" id="btnSubmit" value="Get Current Time"/>  
    }  
    @if (ViewBag.Message != null)  
    {  
        <script type="text/javascript">  
            window.onload = function () {  
                alert("@ViewBag.Message");  
            };  
        </script>  
    }  
</body>  
</html>

Output

This is image title

Summary

In this section, I explained the message sent from Controller to View, which will be displayed In JavaScript alert MesssageBox using the ViewBag object.

Thank you for reading !

#javascript #alert #tutorial #developer