What is MVVM pattern?

What is MVVM pattern?

Ans. MVVM stands for Model-View-View Model. This pattern supports two-way data binding between view and View model. This enables automatic propagation of changes, within the state of view model to the View. Typically, the view model uses the observer pattern to notify changes in the view model to model.

Model - The Model represents a set of classes that describes the business logic and data. It also defines business rules for data means how the data can be changed and manipulated.

View - The View represents the UI components like CSS, jQuery, html etc. It is only responsible for displaying the data that is received from the controller as the result. This also transforms the model(s) into UI.

View Model - The View Model is responsible for exposing methods, commands, and other properties that helps to maintain the state of the view, manipulate the model as the result of actions on the view, and trigger events in the view itself.

This pattern is commonly used by the WPF, Silverlight, Caliburn, nRoute etc.

Key Points about MVVM Pattern

1. User interacts with the View.
2. There is many-to-one relationship between View and ViewModel means many View can be mapped to one ViewModel.
3. View has a reference to ViewModel but View Model has no information about the View.
4. Supports two-way data binding between View and ViewModel.

What is MVVM pattern?

What is MVP pattern?

What is MVP pattern?

Ans. This pattern is similar to MVC pattern in which controller has been replaced by the presenter. This design pattern splits an application into three main aspects: Model, View and Presenter.

Model - The Model represents a set of classes that describes the business logic and data. It also defines business rules for data means how the data can be changed and manipulated.

View - The View represents the UI components like CSS, jQuery, html etc. It is only responsible for displaying the data that is received from the presenter as the result. This also transforms the model(s) into UI.

Presenter - The Presenter is responsible for handling all UI events on behalf of the view. This receive input from users via the View, then process the user's data with the help of Model and passing the results back to the View. Unlike view and controller, view and presenter are completely decoupled from each other’s and communicate to each other’s by an interface.
Also, presenter does not manage the incoming request traffic as controller.

This pattern is commonly used with ASP.NET Web Forms applications which require to create automated unit tests for their code-behind pages. This is also used with windows forms.

Key Points about MVP Pattern
1. User interacts with the View.
2. There is one-to-one relationship between View and Presenter means one View is mapped to only one Presenter.
3. View has a reference to Presenter but View has not reference to Model.
4. Provides two way communication between View and Presenter.

What is MVP pattern?

Explain MVC design pattern?

Explain MVC design pattern?

Ans. MVC design pattern splits an application into three main aspects: Model, View and Controller
Model - The Model represents a set of classes that describe the business logic i.e. business model as well as data access operations i.e. data model. It also defines business rules for data means how the data can be changed and manipulated.
View - The View represents the UI components like CSS, jQuery, html etc. It is only responsible for displaying the data that is received from the controller as the result. This also transforms the model(s) into UI.
Controller - The Controller is responsible to process incoming requests. It receives input from users via the View, then process the user's data with the help of Model and passing the results back to the View. Typically, it acts as the coordinator between the View and the Model.

Today, this pattern is used by many popular framework like as Ruby on Rails, Spring Framework, Apple iOS Development and ASP.NET MVC.

Explain MVC design pattern?

What is MVC?

What is MVC?

Ans. MVC stands for Model-View-Controller. It is a software design pattern which was introduced in 1970s. Also, MVC pattern forces a separation of concerns, it means domain model and controller logic are decoupled from user interface (view). As a result maintenance and testing of the application become simpler and easier.

What is MVC?

What is Domain Driven Design and Development?

What is Domain Driven Design and Development?

Ans. Domain-Driven Design (DDD) is a collection of principles and patterns that help developers to take design decisions to develop elegant systems for different domains. It is not a technology or methodology.

The main components of DDD are: Entity, Value Object, Aggregate, Service and Repository.
Entity- An object that has an identity- it is unique within the system, like Customer, Employee etc.
Value Object- An object that has no identity within the system like Rate, State etc.
Note: A value object can become an entity depending on the situation.
Aggregate: An aggregate root is a special kind of entity that consumers refer to directly. All consumers of the aggregate root are called as aggregate. The aggregate root guarantees the consistency of changes being made within the aggregate.
Service- A service is a way of dealing with actions, operations and activities within your application.
Repository- A repository is responsible to store and to retrieve your data. It is not a concern how and where data will be persist. So, it can be SQL server, oracle, xml, text file or anything else. Repository is not a Data Access Layer but it refers to a location for storage, often for safety or preservation.

What is Domain Driven Design and Development?