Omar AL Zabir blog on ASP.NET Ajax and .NET 3.5

Ajax Portal using VS 2008 and .NET 3.5

I have built an Ajax Web Portal (just like Sharepoint or Google IG) using Linq to SQL, Linq to XML, Workflow Foundation and ASP.NET AJAX 3.5. Although it's no where close to any real Portal, but it works as a great example to show how web applications can implement a widget enabled architecture just like Sharepoint. It also showcases how these hot technologies can play together in a complete web application.

Full source code is in Visual Studio 2008 using .NET 3.0 and .NET 3.5.

CodePlex site
http://www.codeplex.com/dropthings

Production site
http://www.dropthings.com

Code Project article that explains the architecture and development steps
http://www.codeproject.com/Ajax/MakingGoogleIG.asp

Technologies

• ASP.NET 3.5
• ASP.NET AJAX (.NET 3.5)
• Linq to Sql
• Linq to Xml
• Workflow Foundation (.NET 3.0)
• Visual Studio 2008 and SQL Server 2005

Technology Stack

What is an AJAX Portal
A portal refers to a page that allows users to customize their own homepage by dragging and dropping widgets onto the page. This approach gives users complete control over what content they see on their Start Page, where they want to see it, and how they want to interact with it.
A widget is a discrete piece on a Web page that performs a particular function and comes with its own UI and set of features. Examples of widgets include a to-do-list, an address book, a contact list, an RSS feed, or even a clock, calendar, playlist, stock ticker, weather report, traffic report, dictionary, game, or almost anything you can imagine that can be packaged up and dropped on a Web page. In a corporate environment, widgets can connect to internal systems, such as an Expense Tracker widget that interacts directly with the internal Accounting System. If you are familiar with Sharepoint Portal, then you already know about Widgets. They are called Web parts in Sharepoint’s term and also in ASP.NET 2.0.
Portals are powerful RSS aggregation platform. You can put as many RSS widgets as you like on your page and get fresh content delivered to you as soon as it is published.
An Ajax-powered portal is specifically a portal that uses Ajax technologies to create richer experiences for its users. It is one step ahead of previous generation portals like My Yahoo or MSN.com, because it gives you state-of-the-art UI that behaves more like a Windows client application -- with widgets, animations, popups, client side data grids, and other effects not usually found on a non-Ajax Web portal.

How to run the project

1. Install Visual Studio 2008 (VS 2005 won't work)
2. Install SQL Server 2005
3. Download latest code from CodePlex site.
4. Restore the database from database\dashboard.zip
5. Update web.config from the web project and set proper connection string
6. Build and Run

How is ASP.NET AJAX used in this project?
It is an N-tier application, with a user interface (UI) layer, a business layer, and a data access layer. I have used ASP.NET AJAX to implement the UI layer of the portal application which includes the homepage and the widgets’ UI. ASP.NET AJAX provides the framework for loading widgets onto the Start page, updating widgets without doing any postbacks (via UpdatePanel), and changing page layout by dragging and dropping widgets on the page. It also provides a rich collection of Control Extenders, that add cool effects like fade in/fade out, smooth transitions, and client side animations . You can add to the rich client-side experience by providing auto-completion behavior on text boxes, asynchronous data loading via webservice calls, and client-side paging, sorting and many more.

How is .NET 3.5 used in this project
The business layer of the application is built with the Workflow Foundation in .NET 3.0 . Major operations like a first-time user visit, a subsequent user visit, adding a new widget, and creating a new page are all orchestrated using workflow . The workflows contain all the business rules and activities needed to complete each operation. For example, the "New User Visit" workflow creates the user account, populates the user profile with default values, creates some default pages, populates them with specific widgets, etc. Such compound operations are very easy to build with Workflows , which enables you to break the complete workflow operation into smaller chunks named Activities. Each Activity does a very small amount of work. It talks to the data access layer and performs the task. The data access layer is built with .NET 3.5 , utilizing LINQ to SQL .
The web project and the widgets make good use of .NET 3.5 by utilizing lambda expressions , LINQ to SQL, and LINQ to XML. You will use Linq queries to work with collections and database rows. Widgets make good use of Linq to Xml in order to consume XML from external data sources.

The above figure shows an workflow that creates the default homepage for a new user.

You are invited to participate in continued development of the project. If you want to develop widgets, you can download the code, develop the widget offline and then send me the widget related files. I will put them up on the production site. If you want to participate in core development, let me know and I will make you a developer on the codeplex project. Then you can check out code, work on it and then check in when you are done.

Warning: Dropthings.com is a very simple, open-source example of what can be done with AJAX and Microsoft technologies.  It is intended for educational purposes only.  Dropthings.com has absolutely nothing to do with pageflakes.com, and has no code or technology in common.  Trust me, you could not possibly build a product as advanced, scalable and complex as Pageflakes using the examples here, and you’d be insane to try :-) But this project does a good job to show you how all these technologies work together in a working web application.