MVC Application Using n-tier Architecture

Introduction

This article explains how to create a real time MVC Web Application using n-tier architecture. The complete article goes through a sample customer information solution.

Modules

1. Create a SampleCustomerInformation database using SQL Server.
   
   
2. Create an empty MVC web application (Presentation Layer) using Visual Studio 2013.
   
   a. Creating controllers, views and respective HTML and JavaScript required.
   
   
3. Adding another project to the solution for processing the data from SQL Server. Create a C# library project (Data Access Layer).
   
   a. Add an entity data model to connect to the database.
   b. Create classes to process all the requests from Business Service Layer
   c. Write necessary methods to process the requests in business service layer.
   
   
4. Add another project to the solution for writing business logic. Create a WCF Service Library:
   
   a. Add necessary service parameters to the project required to write business logic
   b. Write necessary operation contracts to make available for Presentation Layer
   c. Use all the available methods from Data Access Layer to process data in Service Layer.
   
   
5. Add necessary references to the projects in the solution.
   
   
6. Add a Service Reference to Presentation Layer.
   
   a. Use all the available methods from service layer and process the requests.

Technologies Used

1. ASP.NET MVC 5
2. SQL Server 2014
3. C# v5
4. jQuery 2.14
5. HTML5
6. CSS3

IDE: Visual Studio 2013

Using the code

Module 1:

Module 2:

Create an empty MVC web application (Presentation Layer) using Visual Studio 2013, creating controllers, views and respective HTML and JavaScript required. Here, I used ajax jQuery to send data from View to Controller.

Some of many properties which can be used on ajax request,

1. Method: Specify the type of operation (ex-GET, POST).
2. Url: specify the path of the method.
3. Data: specify the data which needs to transferred from View to Controller for processing.
4. Success: Can specify set of statements needs to be done when success.
5. Failure: Can specify set of statements needs to be done when failure.

More information about jQuery Ajax can be found here: jQuery Ajax

HTML

JavaScript
Module 3:

Adding another project to the solution for processing the data from SQL Server. Create a C# library project (Data Access Layer),

• Create classes to process all the requests from Business Service Layer.
• Write necessary methods to process the requests in business service layer.
  
  1. public class RegisterCustomerDataAccessLayer {#region Register Customer
  2. public bool RegisterCustomer(string firstName, string lastName, string email, string phoneNumber, string password)
  3. {
  4. try {
  5. using(var dbContext = new SampleCustomerInformationEntities())
  6. {
  7. CustomerInformation newCustomer = new CustomerInformation();
  8. newCustomer.CustomerID = 2;
  9. newCustomer.First_Name = firstName;
  10. newCustomer.Last_Name = lastName;
  11. newCustomer.Email = email;
  12. newCustomer.Phone = phoneNumber;
  13. newCustomer.Password = password;
  14. newCustomer.User_Name = email;
  15. dbContext.CustomerInformations.Add(newCustomer);
  16. dbContext.SaveChanges();
  17. return true;
  18. }
  19. } catch (Exception ex)
  20. {
  21. throw new Exception(ex.Message);
  22. }
  23. }#endregion
  24. }
  26. public class CustomerLoginDataAccessLayer
  27. {#region Customer Login
  28. public bool LoginCustomer(string userName, string loginPassword)
  29. {
  30. try {
  31. using(var dbContext = new SampleCustomerInformationEntities())
  32. {
  33. CustomerInformation customer = new CustomerInformation();
  34. customer = dbContext.CustomerInformations.FirstOrDefault(x => x.User_Name == userName && x.Password == loginPassword);
  35. if (customer != null)
  36. return true;
  37. else
  38. return false;
  39. }
  40. } catch (Exception ex)
  41. {
  42. throw new Exception(ex.Message);
  43. }
  44. }#endregion
  45. }

Module 4:

Add another project to the solution for writing business logic. Create a WCF Service Library.

A Service Contract defines what all the methods or operations available to the client from service endpoint. A service contract is an interface and it tells the client what service can do.

An Operation Contract is defined within the service contract and it has return type and parameters. Those operation contracts are implemented in the class which extends the service interface. Client can use this method to do operations.

A Data Contract describes the information which needs to be exchanged and it can be used in any operation contract as a parameter or return type. Based on the parameters and return types the data will be serialized/de-serialized to or from (Binary ó XML).

A Data Member attribute needs to be applied all the members of the data contract to indicate it as a data member, which means it should be serialized.

More information about Service Contracts can be found here: Designing Service Contracts.
More information about Data Contracts can be found here: Using Data Contracts.

• Write necessary operation contracts to make available for Presentation Layer.
• Use all the available methods from Data Access Layer to process data in Service Layer.

Module 6: Add a Service Reference to Presentation Layer,

To add a service reference,

• Right click on the references folder in the client side.
• Click Add Service Reference.
• Service reference can be found by entering the endpoint url or by clicking Discover.
• Select the necessary service references and all the service contracts and operation contracts available can be accessed.
  
  Detailed information about consuming web service can be found here: Consuming Web Service.

Controller: Use all the available methods from service layer and process the requests,