Software Design Patterns

1. Студент : Наджа Аль Кузаи
Группа : 1372
(СПбГЭТУ «ЛЭТИ»)
MVC – Model , View , Controller
MVP – Model , View , Presenter
MVVM – Model , View , View Model
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2. Software Architecture
Software architecture is a technical blueprint explaining how the
system will be structured
• The system architecture describes:
– How the system will be decomposed into subsystems (modules),
– Responsibilities of each module,
– Interaction between the modules,
– Platforms and technologies used,
• Each module could also implement a certain architectural model / pattern.
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3. Multi-Tier Architecture
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DB
ORM
WCF
ASP
.NET
HTML

4. The 3-Tier Architecture
• The 3-tier architecture consists of the following
tiers (layers):
– Front-end (client layer)
• Client software – provides the UI of the system
– Middle tier (business layer)
• Server software – provides the core system logic
• Implements the business processes / services
– Back-end (data layer)
• Manages the data of the system (database / cloud)
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5. The 3-Tier Architecture Model
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Business Logic
Desktop
Client
Mobile
Client
Client
Machine
Database
Data Tier
(Back-End)
Middle Tier
(Business Tier)
Client Tier (Front-End)

6. Typical Layers of the Middle Tier
• The middle tier usually has parts related to the
front-end, business logic and back-end:
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Presentation Logic
Implements the UI of the application (HTML5, Silverlight, WPF, …)
Business Logic
Implements the core processes / services of the application
Data Access Logic
Implements the data access functionality (usually ORM framework)

7. MVC (Model-View-Controller)
What is MVC and How It Works?
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8. Model-View-Controller (MVC)
• MVC is one of three ASP.NET programming models.
• MVC. Presented by Trygve Reenskaug in 1979
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9. Model-View-Controller (MVC)
Model–view–controller (MVC) is a software design pattern
(architectural pattern) for implementing user interfaces . It
divides a software application into three interconnected
parts,
– Separates the business logic from application data and presentation:
• Model
– Keeps the application state (data)
• View
– Displays the data to the user (shows UI) , visible layer
• Controller
– Handles the interaction with the user , manages Views & user interaction
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10. MVC- Environment
• .NET
– ASP.NET MVC, MonoRail
• Java
– JavaServer Faces (JSF), Struts, Spring Web MVC, Tapestry,
JBoss Seam, Swing
• PHP
– CakePHP, Symfony, Zend, Joomla, Yii, Mojavi
• Python
– Django, Zope Application Server, TurboGears
• Ruby on Rails
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11. MVC
MySQL/ NoSQL/MongoDB
PHP / Rubby / Paython
Linux / Windows Server
HTML, Java Script/ CSS
Browser/firefox/Internet explorer
Client
Contains all storage
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12. MVC-Based Frameworks
MODEL:
Adding & receiving items from DB
Processing Data from/to DB
Speaking only with controller
VIEW:
Only this that user sees.
Speaking only with controller
CONTROLLER:
Takes info from user.
Processes info & talks to DB if needed.
Receives info from DB.
Speaks to VIEW to explain presentation.
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13. Model-View-Presenter (MVP)
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14. MVP (Model-View-Presenter)
• Model-View-Presenter (MVP) is UI design pattern
similar to MVC
– Model
• Keeps application data (state)
– View
• Presentation – displays the UI and handles UI events (keyboard,
mouse, etc.)
– Presenter
• Presentation logic (prepares data taken from the model to be
displayed in certain format)
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15. MVVM Model-View-ViewModel
• Model-View-ViewModel (MVVM) is architectural
pattern for modern UI development
Invented by Microsoft for use in WPF and Silverlight
Based on MVC, MVP and Martin Fowler's Presentation
Model pattern
Officially published in the Prism project (Composite
Application Guidance for WPF and Silverlight)
Separates the "view layer" (state and behavior) from the
rest of the application
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16. MVVM Structure
• Model
– Keeps the application data / state representation
– E.g. data access layer or ORM framework
• View
– UI elements of the application
– Windows, forms, controls, fields, buttons, etc.
• ViewModel
– Data binder and converter that changes the Model
information into View information
– Exposes commands for binding in the Views.
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17. MVVM Structure
MVVM is typically used in XAML applications (WPF,
Silverlight, WP7) and supports unit testing.
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18. Comparison
MVC - Model View Controller
• The input is directed at the Controller first.
• Many-to-one relationship between the Controller and the View.
• One-to-one relationship from Controller to View.
• The Controller returns back to the Model, so there is knowledge between the View and the
expected Model being passed into it.
MVP – Model View Presenter
• The input begins with the View, not the Presenter.
• There is a one-to-one relationship between the View and the Presenter.
• The View holds a reference to the Presenter which is aware of the View its associated with.
• The Presenter updates the View based on the requested actions it performs on the Model, but the
View is not Model aware.
MVVM – Model View View Model
• The input begins with the View, not the View Model.
• While the View holds a reference to the View Model, the View Model has no information about the
View.
• One-to-many relationship between multiple Views and one View Model.
• For example, a WPF View and a Silverlight View could share the same View Model.
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19. Вопросы
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20. Спасибо за внимание
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