This presentation will help you to understand the best design methodologies that are used in the industry

1. .NET Solutions DSK Chakravarthy http://dskc.blogspot.com

11. Design Patterns an Example Problem: You are building a Quote Application, which contains a class that is responsible for managing all the quotes in the system. It is important that all quotes interact with one and only one instance of this class. How do you structure your design so that only one instance of this class is accessible with in the application? Solution: A simple solution to this problem is to create a QuoteManager class with a private constructor so that no other class can instantiate it. This class contains a static instance of QuoteManager that is returned with a static method named GetInstance () . Can you design the code for the same?

12. Design Patterns an Example public class QuoteManger { // NOTE: For single threaded application only private static QuoteManagaer _Instance = null; private QuoteManager () {} private static QuoteManager GetInstance () { if (_Instance==null) { _Instance = new QuoteManager (); } return _Instance; } } NOTE: This kind of Pattern is said as “Singleton Pattern”

14. Services n Integration Specialisation means not doing the Extraordinary things, but doing Ordinary things Extraordinarily well... So, What are you doing?

16.  How do I resolve? # You can implement communication between them by using message-based technologies # You can implement message communication by i) Explicitly – By writing code to send and receive Message Queuing Messages. Ex. MSMQ ii) Implicitly – By using Infrastructure components that manage communication. Ex. A Web service proxy by VS.NET Services n Integration ?s

17.  How are the services differ from Components? # Services exists in their own trust boundary and manage their own data, out side your application  What is crucial between Services & Application integration? # Establishing a secure, authenticated connection  What should I be aware, while using a service? # The internal implementation is irrelevant to your design # But need to know the business functionality that the service provides # Also the details of the contract you must adhere to in order to communicate with it such as i) Communication Format ii) Data Schema iii) Authentication Mechanism etc., Services n Integration ?s

18.  What a service contain? # The same kind of components that any traditional application do # You can categorise them as i) Logic Components : That orchestrate the tasks they do ii) Business Components : That implement the actual BL iii) Data Access Components : that access the service’s data store iv) Interfaces : That expose the functionality  What happens when I integrate a service? # Your application will also call other services through “ Service agents ”, which communicate with service on behalf of the calling client application Services n Integration ?s

20. A small scenario A Retail application Sequence Diagram

21. Components and Tiers in Application Imagination is more important than knowledge

24. Component design A Retail application Component Diagram You might design the one like this . . .

25. Simplified View Here comes the simplified view of any general application and it’s layers

26. A Detailed View The previous scenario for the detailed design would look like . . . .

28. Tea Break

29. Components - In detail Knowing the path to failure is as important as Knowing the path to success

30. Component Types Note : The term component is used in the sense of a piece or part of the overall solution. This includes compiled software components such as Microsoft .NET assemblies, and other software artifacts such as Web pages and Microsoft BizTalk Server schedules

32. Designing Presentation Layers

34. Designing UI Components ShowProducts() { // Code to // get product // data } Controller When a user interacts with a user interface element, an event is raised that calls code in a controller function, which inturn calls business components, data access logic components (or) user process components to implement the desired action and retrieve any necessary data..

35. A Small Scenario You are designing a web-based quote application containing a great deal of business and presentation logic, which, in turn, depends on numerous platform software components to provide a suitable execution environment. How do you organise your system at a high level to be flexible, loosely coupled, and yet highly cohesive? Can you rearrange wrf to Layers? CustomerManagement Inventory Management CustomerWebPages Utility Quote WebPages Quote Management Price Engine ADO.NET QuoteDataAccess

36. Solution Scenario Can you rearrange any? The solution could be as.. .. .. .. CustomerManagement Inventory Management CustomerWebPages Utility Quote WebPages Quote Management Price Engine ADO.NET QuoteDataAccess Quote Presentation Layer Quote Business Layer Quote Data Access Layer

41. These help the user interactions synchronize with the UI Components , it is a best practise to drive the process using separate User Process Components User process components are typically implemented as .NET classes that expose methods that can be called by user interfaces. Each method encapsulates the logic necessary to perform a specific action in the UP The user interfaces creates instances of the user process component and uses it to transition through the steps of process You should design them with globalization in mind to allow for localization to be implemented in the User Interface Note : User process components co-ordinate the display of user interface elements Task for You : Can you design common ProcessComponent for the previous Retail application ? UP Components

42. UP Components Example namespace PurchaseUserProcess{ public class PurchaseUserProcess{ public PurchaseUserProcess(){ userActivityID= System.Guid.NewGuid(); } private int intCustomerID; private DataSet dsOrderData; private DataSet dsPaymentData; private Guid userActivityID; public bool webUI; public void ShowOrder() { if(webUI){ System.Web.HttpContext.Current.Response.Redirect("http://www.myserver.com/orderDetails.aspx"); } else{ OrderDetails = new OrderDetailsForm(); OrderDetails.Show(); } } public void EnterPaymentDetails() { // code to display the Payment details page or window goes here } public void ShowConfirmation() { // code to place the order goes here } public void Finish() { // code to go back to the main page or window goes here } public void SaveToDataBase() { // code to save order and payment info in the private variables to a database } public void ResumeCheckOut(System.Guid ProcessID) { // code to reload the process state from the Database } public void Validate() { // code to make sure the process instance variables have the right information for the current step } } }