February 3rd, 2015

Realtime Voting App with ASP.NET SignalR, React.js and D3.js

This tutorial shows how to build a survey or voting app that displays poll results in real-time using ASP.NET SignalR, React.js and D3.js.

ASP.NET SignalR: to build the real time voting app, then broadcast the live result as votes come in.
D3.js: For data visualization. (Creating Pie chart to show the result)
React.js: To update UI in a very efficient manner for real time changes.

If you are new to React.js, I strongly recommend to read following tutorial:
React.js: Introduction and Hello World with ASP.NET MVC 5

July 6th, 2013

Realtime Maps Based On XML File Changes With SignalR and ASP.NET MVC

This article explores how to implement realtime Google and Bing Maps based on XML file changes by external system. It can be used in many ways like to track and display real-time position of bus, train or flight in the maps.

1. Assuming the external system inserts current location in XML file.
2. The .NET FileSystemWatcher object is used to monitor XML File changes. When a location is inserted, the FileSystemWatcher fires an event to notify that a change has occurred.
3. On change event, the current location is passed to client using SignalR
4. The map is updated by client side code.

June 5th, 2013

Realtime Wall Post and Comment Notifications using SignalR and Knockout

In my previous post, we created Facebook style wall posts and comments system. In this post, we will implement real time notification when any new post or comment is added and display it on notification click using Knockout JS and SignalR. You might think .. Why notification? Why not to display in real time? If we display it in real time, It will irritate users. Suppose you are reading a post middle of the page, suddenly few new posts appear on top then the post you are reading go down and you have to scroll down to find where it is. That’s why in twitter or Stackoverflow,the notification is used when any new post is arrived and you can check them on notification click. We will implement the same thing for both posts and comments.

January 13th, 2013

Database Change Notifications in ASP.NET using SignalR and SqlDependency

This article shows how to display real time sql server database change notification in ASP.NET using SignalR and SqlDependency object which represents a query notification dependency between an application and an instance of SQL Server. Consider your database is updated or synchronized by windows service in background, you have to display real time updated data. This article explains how to implement it.

October 20th, 2012

Real Time Chart With SignalR and ASP.NET MVC

In my recent post, we have implemented Real-Time Chart using HTML5 Push Notification (SSE) and ASP.NET Web API. I got many requests to implement it using SignalR. So In this tutorial, we are going to display real-time updates with SignalR and ASP.NET MVC. SignalR is an async signaling library for ASP.NET to help build real-time, multi-user interactive web applications. It makes easy to push data from the server to the client.