Software Design Patterns

Software Design Patterns

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  Студент : НаджаАль Кузаи Группа : 1372 (СПбГЭТУ «ЛЭТИ») MVC – Model , View , Controller MVP – Model , View , Presenter MVVM – Model , View , View Model 1
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  Software Architecture Software architectureis 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. 2
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  Multi-Tier Architecture 3 DB ORM WCF ASP .NET HTML
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  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) 4
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  The 3-Tier ArchitectureModel 5 Business Logic Desktop Client Mobile Client Client Machine Database Data Tier (Back-End) Middle Tier (Business Tier) Client Tier (Front-End)
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  Typical Layers ofthe Middle Tier • The middle tier usually has parts related to the front-end, business logic and back-end: 6 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)
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  MVC (Model-View-Controller) What isMVC and How It Works? 7
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  Model-View-Controller (MVC) • MVCis one of three ASP.NET programming models. • MVC. Presented by Trygve Reenskaug in 1979 8
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  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 9
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  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 10
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  MVC MySQL/ NoSQL/MongoDB PHP /Rubby / Paython Linux / Windows Server HTML, Java Script/ CSS Browser/firefox/Internet explorer Client Contains all storage 11
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  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. 12
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  Model-View-Presenter (MVP) 13
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  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) 14
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  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 15
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  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. 16
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  MVVM Structure MVVM istypically used in XAML applications (WPF, Silverlight, WP7) and supports unit testing. 17
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  Comparison MVC - ModelView 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. 18
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  Вопросы 19
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  Спасибо за внимание 20