Model View Controller
                     Design Pattern


Guided By:                            Submitted By :
Dr. Avinash Panwar                    Abhishek Yadav
                                      Shashwat S Mehta
                                      Sourabh Jain
HOW
MVC ?


WHAT’s
MVC ?



WHY
MVC ?
Overview:
 1.   Design Patterns
 2.   Why MVC
 3.   What is MVC
 4.   Alternative Patterns
 5.   Implementation Frameworks
 6.   Benefits and Disadvantages




                                   3
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 ++

                                                     4
MVC
Pattern? Architecture? Framework?




                          5
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). “




                                                6
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.”




                                                           7
Framework:


A software framework is a universal, reusable software platform used to
develop applications, products and solutions.




                                                         8
A Generic MVC Framework
                          9
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


                                                       10
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




                                                     11
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



                                                      12
Example

      13
Alternatives
         14
THE
MODEL-VIEW-PRESENTER
       (MVP)
      PATTERN


               15
The Taligent Model-View-Presenter
              Pattern




                         16
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



                                                           17
The Dolphin Smalltalk Model-
   View-Presenter Pattern




                      18
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.




                                                     19
The Supervising Controller Pattern




                         20
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.




                                                   21
The Passive View Pattern




                    22
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




                                                   23
The
Presentation-Abstraction-Control
             (PAC)
             Pattern

                       24
25
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


                                               26
MVC
Implementations

            27
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.


                                  28
29
30
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




                                        31
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


                                             32
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


                                                33
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.




                                                                    34
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


                                                               35
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.


                                                                36
• 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
                                                       37
Benefits


 • Supports Test Driven Development


 • Supports multiple views


 • Accommodates change

                                 38
Disadvantages

 • Complexity

 • Cost of frequent updates




                              39
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


                                                               40
Thank you !!

MVC Seminar Presantation

  • 1.
    Model View Controller Design Pattern Guided By: Submitted By : Dr. Avinash Panwar Abhishek Yadav Shashwat S Mehta Sourabh Jain
  • 2.
  • 3.
    Overview: 1. Design Patterns 2. Why MVC 3. What is MVC 4. Alternative Patterns 5. Implementation Frameworks 6. Benefits and Disadvantages 3
  • 4.
    Problem Without Separation ofconcerns 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 ++ 4
  • 5.
  • 6.
    Pattern: “ Each patternis 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). “ 6
  • 7.
    Architectural Pattern: Fundamental structuralorganization 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.” 7
  • 8.
    Framework: A software frameworkis a universal, reusable software platform used to develop applications, products and solutions. 8
  • 9.
    A Generic MVCFramework 9
  • 10.
    Model • represents anapplication’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 10
  • 11.
    View • responsible forrendering 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 11
  • 12.
    Controller • responsible forintercepting 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 12
  • 13.
  • 14.
  • 15.
    THE MODEL-VIEW-PRESENTER (MVP) PATTERN 15
  • 16.
  • 17.
    Components • Modelrefers 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 17
  • 18.
    The Dolphin SmalltalkModel- View-Presenter Pattern 18
  • 19.
    Components • The Modelrefers 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. 19
  • 20.
  • 21.
    Components • The Viewis 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. 21
  • 22.
    The Passive ViewPattern 22
  • 23.
    Components • The Viewis 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 23
  • 24.
  • 25.
  • 26.
    Components • The Presentationis 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 26
  • 27.
  • 28.
    MVC Implementation inJ2EE 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. 28
  • 29.
  • 30.
  • 31.
    Model 1 andModel 2 In the design of Java Web applications, there are two commonly used design models, referred to as Model 1 and Model 2 31
  • 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 32
  • 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 33
  • 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. 34
  • 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 35
  • 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. 36
  • 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 37
  • 38.
    Benefits • SupportsTest Driven Development • Supports multiple views • Accommodates change 38
  • 39.
    Disadvantages • Complexity • Cost of frequent updates 39
  • 40.
    References: 1. A TimelessWay 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 40
  • 41.