Rami Vemula

  Often we write lot of extension methods which helps us in consolidating logic and performing operations on objects in a easy way. In this tutorial I m going to narrate on how to implement IEnumerable<T> on extension methods which helps us in extending our extension method on every object which implements IEnumerable implementation say [...]

In this part of the tutorial, we carry on with the construction of MVP Pattern. First we start with the creation of View interfaces for the UserControls (which we created in PART II). Then we create the presenter classes, which will take the corresponding instances of views and then manipulate the view using Model classes (there by achieving code portability). Once we are done with the presenter classes, we implement the View interfaces in the codebehind of the UserControls. Finally we create a sample ASP.Net web page (typically webform), and use the UserControls for database transactions.

In this part of the tutorial – We first code for the CustomerService.cs by implementing ICustomerService.cs interface. We use LINQ queries to code database transactions. Then we create a host application (here it is a Console application) which operates the WCF service. Then we create a sample website for implementing MVP Pattern to access WCF. In the website, we implement some UserControls for fetching/updating/deleting records from the database.

First we create a database – ‘CustomersDB’ – with a table in it – ‘Customers’. This table Customers holds the basic data related to each and every customer. Then we create the entity model for this CustomersDB using ADO.Net Entity Framework. After that we create a WCF service with minimal end point configuration to access ServiceContracts which do basic database operations. Instead of coding the data access methods (of the class implementing ServiceContract) in traditional ADO.Net queries, we tend to use LINQ for the same. Once the service is ready, we host it using a Console App. With this we complete the backend of the article. Now we implement the MVP pattern for better separation of UI from its code with the help of presenter class. So we create an interface for both model and view and then implement them in their respective class. Finally we create a UI with some UserControls in it for adding/editing/deleting customers from the front end.

In this tutorial, we see how to develop a simple comments section. This comments section is going to be a similar one to what we usually see in our day to day experience. Here we use TinyMCE editor to enable Html Comments. And also catpcha is enabled (with the help of reCaptcha of Google). The basic outline would be – Users provide their general details like name and email, and also they can provide Html Comment (using TinyMCE), and finally they should enter the text showed in the captcha for validating robots. Then we take the Html string, encode it using HtmlEncode(), store it in database. Finally we retrieve the encoded string from the database, we then decode it and display it in the page as Comment.

1) In this tutorial (which is PART – II), we create a small website in ASP.Net 4.0 and we shall use a WebForm (named: PubsServiceTestPage.aspx) as a client to our service (which we created in former tutorial).
2) We Use the inline model of Webform (not the codebehind model).
3) We perform the actions using our client like, Getting all the Authors and display them in the Dropdownlist for selections, Selecting a Author and display his corresponding books using a Repeater, Modify and save the book details back to database etc.
4) To test the Client, we need the service to be running in the server, that can be simply manipulated by starting another instance of VS 2010 and running (Ctrl + F5) the PubsService.svc.cs.

1) In this tutorial we create a simple WCF service which is used to retrieve and save data from Pubs Database (Microsoft sample database).
2) The service also demos on how to use EF 4.0 and LINQ against database coding, with no requirement of writing SQL queries.
3) The continuation of this tutorial shows on how to create a client (say a WebForm in a website) to utilize this service.