As a part of the course work we were supposed to prepare a seminar on any topic of Interest, So we tried to demystify MVC as a Design pattern.

1. Model View Controller
Design Pattern
Guided By: Submitted By :
Dr. Avinash Panwar Abhishek Yadav
Shashwat S Mehta
Sourabh Jain

2. HOW
MVC ?
WHAT’s
MVC ?
WHY
MVC ?

3. Overview:
1. Design Patterns
2. Why MVC
3. What is MVC
4. Alternative Patterns
5. Implementation Frameworks
6. Benefits and Disadvantages
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4. Problem
Without Separation of concerns a
developer has to rely and wait for
the feeds of others to complete his
tasks. Productivity --
Solution
With separation of concerns by
MVC, he can build applications
faster, Unit test them easily
without any involvement of other
developers. Productivity ++
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5. MVC
Pattern? Architecture? Framework?
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6. Pattern:
“ Each pattern is a three-part rule, which expresses a relation
between a certain context (design context), a certain system of
forces which occurs repeatedly in that context (recurring
design problem), and a certain software configuration which
allows these forces to resolve themselves (solution). “
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7. Architectural Pattern:
Fundamental structural organization for software systems.
Architectural patterns are high-level strategies that concerns large-scale
components, the global properties and mechanisms of a system.
“At the highest level, there are the architecture patterns that define the
overall shape and structure of software applications. Down a level is the
architecture that is specifically related to the purpose of the software
application. Yet another level down resides the architecture of the modules
and their interconnections. This is the domain of design patterns, packages,
components, and classes.”
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8. Framework:
A software framework is a universal, reusable software platform used to
develop applications, products and solutions.
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9. A Generic MVC Framework
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10. Model
• represents an application’s data and contains the logic for accessing
and manipulating that data
• groups related data and operations for providing a specific service
• services accessed by the controller for querying or effecting a change
in the model state.
• The model notifies the view when a state change occurs in the model.
• The Model layer represents the part of your application that
implements the business logic
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11. View
• responsible for rendering the state of the model
• forwards user input to the controller
• View renders a presentation of modeled data
• can be used to deliver a wide variety of formats depending on your
needs
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12. Controller
• responsible for intercepting and translating user input into actions
to be performed by the model
• responsible for selecting the next view based on user input and the
outcome of model operations
• handles requests from users
• can be seen as managers taking care that all needed resources for
completing a task are delegated to the correct workers
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13. Example
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14. Alternatives
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15. THE
MODEL-VIEW-PRESENTER
(MVP)
PATTERN
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16. The Taligent Model-View-Presenter
Pattern
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17. Components
• Model refers to the data and business functionality of the application
• Selections are components which specify what portion of the data within
the Model is to be operated upon
• Commands are components which define the operations which can be
performed on the data
• View is the visual representation of the Model and is comprised of the
screens and widgets used within an application
• Interactors are components which address how user events are mapped
onto operations performed on the Model
• Presenter is a component which orchestrates the overall interaction of the
other components within the application
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18. The Dolphin Smalltalk Model-
View-Presenter Pattern
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19. Components
• The Model refers to the data and business functionality of the
application.
• The View is the visual representation of the Model and is comprised
of the screens and widgets used within an application.
• The Presenter is a component which contains the presentation
logic which interacts with the Model.
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20. The Supervising Controller Pattern
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21. Components
• The View is the visual components used within an application such
as screens and widgets.
• The Controller is a component which processes user events and
the complex presentation logic within an application.
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22. The Passive View Pattern
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23. Components
• The View is the visual components used within an application such
as screens and widgets
• The Controller is a component which processes user events and
the presentation logic within an application
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24. The
Presentation-Abstraction-Control
(PAC)
Pattern
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25. 25

26. Components
• The Presentation is the visual representation of a
particular abstraction within the application
• The Abstraction is the business domain functionality
within the application
• The Control is a component which maintains consistency
between the abstractions within the system and their
presentation to the user in addition to communicating with
other Controls within the system
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27. MVC
Implementations
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28. MVC Implementation in J2EE
Used for separating business layer
functionality represented by JavaBeans or EJBs
(the model) from the presentation layer
functionality represented by JSPs (the view)
using an intermediate servlet based
controller.
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29. 29

30. 30

31. Model 1 and Model 2
In the design of Java Web applications, there are two
commonly used design models, referred to as Model 1
and Model 2
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32. Model 1 Architecture
• a request is made to a JSP or servlet
• JSP or servlet handles all responsibilities for the
request
• commonly used in smaller, simple task applications
• not conducive to large-scale application development
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33. Model 2 Architecture
• separates the display of content from the logic used to obtain
and manipulate the content
• requests from the client browser are passed to the controller
• controller performs any logic necessary to obtain the correct
content for display
• places the content in the request
• view then renders the content passed by the controller
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34. ASP.NET MVC features
• Separation of application tasks, testability, and test-driven development by default
• An extensible and pluggable framework
• powerful URL-mapping component lets you build applications that have
comprehensible and searchable URLs
• Support for existing ASP.NET features
• MVC’s model works through URL routing to specific controller methods and any
operation routes back to a specific method in the controller.
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35. GUI Frameworks
• XPages – for IBM Lotus Notes/Domino
• GTK+ provides models and views, while clients implement the controllers through
signals
• Microsoft Foundation Class Library (MFC) – called the document/view
architecture
• ASP.NET MVC Framework – reusing jQuery libraries and proprietary Microsoft
Ajax libraries
• Microsoft Composite UI Application Block – part of the Microsoft Enterprise
Library
• Oracle Application Development Framework – Oracle ADF
• Java Swing
• Adobe Flex
• Wavemaker – open source, browser-based development tool based on MVC
• Visual FoxExpress is a Visual FoxPro MVC framework
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36. Web Frameworks
• XForms has an integrated MVC architecture with an integral dependency graph, frees
the programmer from specifically having to perform either push or pull operations.
• Ruby on Rails
• Django - A complete Python web application framework, prefers to call its MVC
implementation MTV, for model-template-view.
• Zend Framework - An open-source PHP 5-based framework featuring a MVC layer
and a broad-spectrum of loosely coupled components.
• Joomla - free and open source content management system (CMS) for publishing
content on the World Wide Web and intranets and a MVC Web application framework
that can also be used independently.
• CodeIgniter - simple, light, fast, open source MVC framework for building websites
using PHP.
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37. • CakePHP - A web application framework modeled after the concepts of
Ruby on Rails.
• ASP.NET MVC Framework
• Swing - uses a model-delegator pattern, where the view and controller
are combined, but the model is separate
• Java Hibernate
• Spring MVC Framework
• Struts
• Java Server Faces (JSF)
• Web Dynpro for ABAP & Java
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38. Benefits
• Supports Test Driven Development
• Supports multiple views
• Accommodates change
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39. Disadvantages
• Complexity
• Cost of frequent updates
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40. References:
1. A Timeless Way of Hacking: R Gabriel, in Core J2EE Patterns, Pearson Education.
2. Erich Gamma, Richard Helm, Ralph Johnson and John Vlissides in Design Patterns:
Elements of Reusable Object-Oriented Software,AddisonWesley Professional,
November 10, 1994
3. Roger S Pressman in Software Engineering: A Practitioner's Approach (International
Edition),McGraw-Hill, January 20, 2009
4. Understanding Model-View-Controller in CakePHP cookbook 2.x, Available:
http://book.cakephp.org/2.0/en/cakephp-overview/understanding-model-view-
controller.html
5. David Lloyd, Expresso Developer's Guide, What is MVC, Available:
http://www.jcorporate.com/expresso/doc/edg/edg_WhatIsMVC.html
6. Wikipedia, Model View Controller, Available:
http://en.wikipedia.org/wiki/Model%E2%80%93view%E2%80%93controller
7. Microsoft ASP.NET Team, ASP.NET MVC Overview, Available:
http://www.asp.net/mvc/tutorials/overview/asp-net-mvc-overview
8. MSDN, Model View Controller, Available http://msdn.microsoft.com/en-
us/library/ff649643.aspx
9. John T.Emmatty, Differences between MVC and MVP for Beginners, Available:
http://www.codeproject.com/Articles/288928/Differences-between-MVC-and-MVP-for-
Beginners
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41. Thank you !!