MVC Questions

Source MSDN

1	What is MVC
	MVC is a standard design pattern that many developers are familiar with. The Model-View-Controller (MVC) architectural pattern separates an application into three main components: the model, the view, and the controller. The ASP.NET MVC framework provides an alternative to the ASP.NET Web Forms pattern for creating Web applications. The MVC pattern helps you create applications that separate the  different aspects of the application (input logic, business logic, and UI logic), while providing a loose coupling between these elements. The pattern specifies where each kind of logic should be located in  the application. The UI logic belongs in the view. Input logic belongs in the controller. Business logic  belongs in the model. This separation helps you manage complexity when you build an application, because it enables you to focus on one aspect of the implementation at a time. For example, you can  focus on the view without depending on the business logic. The loose coupling between the three main components of an MVC application also promotes parallel development. For example, one developer can work on the view, a second developer can work on the controller logic, and a third developer can focus on the business logic in the model.
2	In which assembly is MVC framework defined?
	System.Web.Mvc
3	Various Components of MVC?
	The MVC framework includes the following components: Models. Model objects are the parts of the application that implement the logic for the application's data  domain. Often, model objects retrieve and store model state in a database. For example, a Product object might retrieve information from a database, operate on it, and then write updated information back to a Products table in a SQL Server database. In small applications, the model is often a conceptual separation instead of a physical one. For example,  if the application only reads a dataset and sends it to the view, the application does not have a physical  model layer and associated classes. In that case, the dataset takes on the role of a model object.Views. Views are the components that display the application's user interface (UI). Typically, this UI is created from the model data. An example would be an edit view of a Products table that displays text boxes,  drop-down lists, and check boxes based on the current state of a Product object.Controllers. Controllers are the components that handle user interaction, work with the model, and ultimately select a view to render that displays UI. In an MVC application, the view only displays information; the controller handles  and responds to user input and interaction. For example, the controller handles query-string values, and passes these values to the model, which in turn might use these values to query the database.
4	How does MVC supports Test-Driven development?
	MVC pattern makes it easier to test applications than it is to test a Web Forms-based ASP.NET Web application. For example, in a Web Forms-based ASP.NET Web application, a single class is used both to display output and to respond to user input. Writing automated tests for Web Forms-based ASP.NET  applications can be complex, because to test an individual page, you must instantiate the page class, all its child controls, and additional dependent classes in the application. Because so many classes are  instantiated to run the page, it can be hard to write tests that focus exclusively on individual parts of the application. Tests for Web Forms-based ASP.NET applications can therefore be more difficult to implement than tests in an MVC application. Moreover, tests in a Web Forms-based ASP.NET application  require a Web server. The MVC framework decouples the components and makes heavy use of interfaces, which makes it possible to test individual components in isolation from the rest of the  framework. 5 Advantages of MVC based applications? The ASP.NET MVC framework offers the following advantages: •It makes it easier to manage complexity by dividing an application into the model, the view, and the  controller. •It does not use view state or server-based forms. This makes the MVC framework ideal for developers who want full control over the behavior of an application. •It uses a Front Controller pattern that processes Web application requests through a single controller. This enables you to design an application that supports a rich routing infrastructure. For more information, see Front Controller on the MSDN Web site. •It provides better support for test-driven development (TDD). •It works well for Web applications that are supported by large teams of developers and Web designers who need a high degree of control over the application behavior. 6 Advantages of web-based applications? The Web Forms-based framework offers the following advantages: •It supports an event model that preserves state over HTTP, which benefits line-of-business Web application development. The Web Forms-based application provides dozens of events that are  supported in hundreds of server controls. •It uses a Page Controller pattern that adds functionality to individual pages. For more information,  see Page Controller on the MSDN Web site. •It uses view state or server-based forms, which can make managing state information easier. •It works well for small teams of Web developers and designers who want to take advantage of the large number of components available for rapid application development. •In general, it is less complex for application development, because the components (the Page class, controls, and so on) are tightly integrated and usually require less code than the MVC model.  7  Basic Features of MVC framework? The ASP.NET MVC framework provides the following features:Separation of application tasks (input logic, business logic, and UI logic), testability, and test-driven development (TDD). All core contracts in  the MVC framework are interface-based and can be tested by using mock objects, which are simulated  objects that imitate the behavior of actual objects in the application. You can unit-test the application without having to run the controllers in an ASP.NET process, which makes unit testing fast and flexible. You can use any unit-testing framework that is compatible with the .NET Framework.An extensible and pluggable framework. The components of the ASP.NET MVC framework are designed so that they  can be easily replaced or customized. You can plug in your own view engine, URL routing policy, action-method parameter serialization, and other components. The ASP.NET MVC framework also supports the use of Dependency Injection (DI) and Inversion of Control (IOC) container models. DI  enables you to inject objects into a class, instead of relying on the class to create the object itself.  IOC specifies that if an object requires another object, the first objects should get the second object from an outside source such as a configuration file. This makes testing easier.Extensive support for  ASP.NET routing, which is a powerful URL-mapping component that lets you build applications that have comprehensible and searchable URLs. URLs do not have to include file-name extensions, and are  designed to support URL naming patterns that work well for search engine optimization (SEO) and representational state transfer (REST) addressing.Support for using the markup in existing ASP.NET  page (.aspx files), user control (.ascx files), and master page (.master files) markup files as view templates. You can use existing ASP.NET features with the ASP.NET MVC framework, such as nested master pages, in-line expressions (<%= %>), declarative server controls, templates, data-binding,  localization, and so on.Support for existing ASP.NET features. ASP.NET MVC lets you use features  such as forms authentication and Windows authentication, URL authorization, membership and roles,  output and data caching, session and profile state management, health monitoring, the configuration system, and the provider architecture. 8  What is REST model? Representational State Transfer, or REST for short? Well, REST is an architectural pattern that defines how network resources should be defined and addressed in order to gain shorter response times, clear separation of concerns between the front-end and back-end of a networked system. REST is based on three following principles: •An application expresses its state and implements its functionality by acting on logical resources •Each resource is addressed using a specific URL syntax •All addressable resources feature a contracted set of operations         9  Difference between ASP.NET and MVC? It is an ASP.NET framework that performs data exchange by using a REST model versus the postback  model of classic ASP.NET. Each page is split into two distinct components -controller and view – that  operate over the same model of data. This is opposed to the classic code-behind model where no  barrier is set that forces you to think in terms of separation of concerns and controllers and views. However, by keeping the code-behind class as thin as possible, and designing the business layer  appropriately, a good developer could achieve separation of concerns even without adopting MVC  and its overhead. MVC, however, is a model superior to a properly-done code-behind for its inherent  support for test-driven development.  10  MVC for ASP.NET programmers? What can be the quickest and most effective way to explain the MVC Framework to ASP.NET  developers. It's like having a central HTTP handler that captures all requests to resources identified with a new extension. This HTTP handler analyzes the syntax of the URL and maps it to a special server  component known as the controller. The controller supports a number of predefined actions. The  requested action is somehow codified in the URL according to an application-specific syntax. The central HTTP handler invokes the action on the controller and the controller will process the request up to generating the response in whatever response format you need. The response is generated through a view component. What here I called the "central HTTP handler" plays the same role that was of the System.Web.UI.Page  class in classic ASP.NET. The Page is the handler responsible for any .aspx request and generates the  markup using the code-behind class and serves it back using postbacks. In the MVC Framework, this  pattern - hard-coded in the ASP.NET runtime and not subject to change until the whole ASP.NET platform is rewritten - is simply implemented using an alternative HTTP handler and an alternative model based on REST and MVC.  11  When to use MVC? I would say one very compelling scenario to use MVC is if you have a group of experienced .NET developers who dont have experience with WebForms. They don't need to go into details and complexity of abstraction and postbacks to use MVC.