Mvc

MVC or Model View Controller is a design pattern. This design pattern has been present in software applications for several decades. The Model View Controller pattern was invented in a Smalltalk context for decoupling the graphical interface of an application from the code that actually does the work.

* Model-Consist of Application data and the business rules. It contains the code to manipulate the data (From Database or any data source) & Also the Objects that retrieve the data. It represent the state of particular aspect of the application. Eg: Model Maps to Database Table and entries in table represent the state of the application. Model is responsible for actual data processing, like database connection, querying database, implementing business rules etc. It feeds data to the view without worrying about the actual formatting and look and feel.

* Controller- Handles user interaction, Reads data from view, Controls Input & Send input data to the model. Handles Inputs and update the model to reflect the change in state of the application. It also pass information to the view. Controller is responsible for Notice of action. Controller responds to the mouse or keyboard input to command model and view to change. Controllers are associated with views. User interaction triggers the events to change the model, which in turn calls some methods of model to update its state to notify other registered views to refresh their display.

* View-Is an output, It could be a webpage or a printout. In short views are used to display the data. Most of the time we create views from the model data. It accepts information from the controller and displays it. View is the graphical data presentation (outputting) irrespective of the real data processing. View is the responsible for look and feel, some custom formatting, sorting etc. View is completely isolated from actual complex data operations.

1. Separation of Concerns

2. Better Support for Test Driven Development

3. Clean URL

4. Better for Search Engine Optimization

5. Full Control over the User Interface or the HTML

6. Loosely coupled so Each Component can be tested independently.

Controllers and Action Methods in ASP.NET MVC Applications

Before entering to the coding side we must have some basic knowledge about MVC that is what MVC is,, what are its applications and what are the advantages of using MVC architecture etc..

ASP.NET MVC is the Microsoft's Web application frame work and the other one is the web form frame work.

As the name specifies MVC contains

1. Model

2.View

3.Controller

MVC Frameworks maps the URLs to Controllers (or controller action methods.). And the controller processes the input or incoming request and calls a View (That is our html output).Model does the business logics in the projects that needed by the View to populates the output and controller used the model to save data, update data etc.

Controller class is responsible for

1. Locating the action methods.

2. Getting the arguments for action method.

3. Processing the action method and handles the errors during the processing phase.

4. Call the appropriate View (Html output) pages

Action Methods

User gives request to the controller via URL. And the Controller processes the requests using the

action methods defined by the Controller. For example the given below is the HomeController for a

new project. Index and About are the action method of HomeController.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Mvc;

namespace MvcApplication2.Controllers

{

public class HomeController : Controller

{ public ActionResult Index()

{ ViewBag.Message = "Welcome to ASP.NET MVC!";

return View(); }

public ActionResult About()

{ return View(); } }}

To invoke the Index method of the HomeController, the URL is

http: xxxxx/Home or http: xxxxx/Home/Index

Because of Index is the default method there is no need to Specify /Home/Index.

And to invoke About method

http://localhost:3471/Home/About

ActionResult Return Type

There are different types of results that are available to you in ASP.NET MVC 3. When creating new

controllers, they will come with one or more actions by default.The Empty controller includes an

Index action with a return value of type ActionResult. ActionResult class is the base class for all

action results.There are different ActionResult types are there,briefly explained below.

ActionResult Helper Method Description

ViewResult View Renders a view as a web page

PartialViewResult PartialViewSection of a view,that can be rendered inside

another view

RedirectResult Redirect Redirect to another action method

RedirectToRouteResult RedirectToRoute Redirect to another action method

ContentResult Content Returns a user-defined content type

JsonResult Json Retuns a serialized JSON object

JavaScriptResult JavaScript Returns a script that can be executed on the client

FileResult File Returns a binary output to write to the response

EmptyResult (None) returns a null result

Action Methods Parameters

Request and Reaponse methods can be called from the action method of the controller.If the

http://localhost:3471/Home/About

parameter to an action method is passing through the URL, there are several ways to access it into

our action method.

The below code explains how to use Request object to access the query-string value.

public void Register()

{ int ID = Convert.ToInt32(Request["ID "]);}

This Tutorial is intended for people who are not familiar with assembly language or assembler at all.

This tutorial will take u though step by step instructions to start creating programs in assembly

language. Even if you are familiar with assembly language this website would be handy if you would

like to go though 8086 instructions or interrupts. We would focus mostly on the coding aspect than

theory.

Non-Action Methods All action methods in a Controller are defined as public method.If you want some method as non

action method,mark the method with NonAction Attribute

[NonAction]

private void function_name()

{ // Method logic.}

Views and UI rendering in ASP.NET MVC

The ASP.NET MVC framework supports view engine to generate views (UI).

Default view page Index.cshtml

@{ ViewBag.Title = "Home Page";}

<h2>@ViewBag.Message</h2>

<p>

To learn more about ASP.NET MVC visit <a href="http://asp.net/mvc"

title="ASP.NET MVC Website">http://asp.net/mvc</a>.

</p>

<!DOCTYPE html>

<html>

<head>

<title>@ViewBag.Title</title>

<link href="@Url.Content("~/Content/Site.css")" rel="stylesheet"

type="text/css" />

<script src="@Url.Content("~/Scripts/jquery-1.5.1.min.js")"

type="text/javascript"></script>

</head>

<body>

<div class="page">

<div id="header">

<div id="title">

<h1>New Project</h1>

</div>

<div id="logindisplay">

@Html.Partial("_LogOnPartial")

</div>

<div id="menucontainer">

<ul id="menu">

<li>@Html.ActionLink("Home", "Index", "Home")</li>

<li>@Html.ActionLink("About", "About", "Home")</li>

</ul>

</div>

</div>

<div id="main">

@RenderBody()

</div>

<div id="footer">

</div>

</div>

</body>

</html>

Automatic Mapping of Action Method Parameters and Incoming Request

Consider our action method have some parameters,mapping of user request data to the parameter

is done automatically in MVC framework.MVC framework examines the user request that if there is

an HTTP request value with same name,then it maps the value automatically to the parameter of

action method.

Consider an examle,Suppose we have a Controller 'Register' and an action method 'Add' in

'Register' Controller.

public ActionResult Add(int id)

{ ViewData["RegisterNumber"] = id;

return View();}

We can also embed the parameter with the URL itself instead of as query-string values.

For example we the URL may be ../Register/Add/5

The default route mapping rule has the format ../{Controller}/{action}/{id}

Helper Classes

There are several Helper classes in MVC frame work.

1.Form Helper- Radio buttons, textboxes,list boxes etc.

2.URL helpers

3.HTML helpers- Encode, Decode, AttributeEncode, and RenderPartial.

Rendering Form using HTML Helpers

Some of the commonly used HTML helpers are

* ActionLink : Link to an action method

@Html.ActionLink("About MVC", "About", "Home")

When We click on th link 'About MVC' it links to the 'About' method in the 'HomeController'.

*TextBox

name: @Html.TextBox("name")

*BeginForm- Marks the start of a form and links to the action method that renders the form.

@using (Html.BeginForm("AddDetails", "admin", FormMethod.Post, new

{ enctype = "multipart/form-data" }))

{

-----Form Content-----

}

When the from submits the data goes to 'AddDetails' action method in the 'adminController'.

*DropDownList- Renders a drop-down list.

The code for the 'Countries' Action method

public ActionResult Countries()

{

List countryList = new List();

countryList.Add("India");

countryList.Add("Pakistan");

countryList.Add("USA");

countryList.Add("Afghanistan");

countryList.Add("China");

countryList.Add("France");

countryList.Add("Japan");

ViewBag.countries = new SelectList(countryList);

return View(); }

The View page of 'Countries' will Contain

Countries :@Html.DropDownList("countries ")

* RadioButton

Select your Country:

@Html.RadioButton("country", "India", true)India

@Html.RadioButton("country", "Pakistan", false)Pakistan

@Html.RadioButton("country", "USA", false)USA

@Html.RadioButton("country", "Afghanistan", false)Afghanistan

@Html.RadioButton("country", "China", false)China

@Html.RadioButton("country", "France", false)France

@Html.RadioButton("country", "Japan", false)Japan

* CheckBox

@Html.CheckBox("country")

* TextArea-Multi-line text box.

URL Helper classes

URL Helper class provide the following methods.

1. Action- Generates a URL that maps to an action method.

Overload Lists.

*Action(String)

*Action(String, Object)

*Action(String, String)

*Action(String, RouteValueDictionary)

*Action(String, String, Object)

*Action(String, String, RouteValueDictionary)

*Action(String, String, Object, String)

*Action(String, String, RouteValueDictionary, String, String)

Syntax for Action(String)

public string Action( string actionName)

2.RouteUrl-Generates a URL that maps to a route.

Overload Lists.

*RouteUrl(Object)

*RouteUrl(String)

*RouteUrl(RouteValueDictionary)

*RouteUrl(String, Object)

*RouteUrl(String, RouteValueDictionary)

*RouteUrl(String, Object, String)

*RouteUrl(String, RouteValueDictionary, String, String)

Syntax for RouteUrl(Object)

public string RouteUrl( Object routeValues)

3.Content-Generates a URL path to a resource, based on the virtual (relative) path of the resource.

Syntax

public string Content( string contentPath)

4.Encode- This method encodes special characters in the specified URL into character-entity

equivalents.

Syntax

public string Encode( string url)

HTML Helper classes

MVC include HTML Helpers like links and HTML form elements.

Links include HTML.ActionLink() helper.

Razor syntax of ActionLink is

@Html.ActionLink("About MVC", "About", "Home")

The Html.ActionLink() helper above, outputs the following HTML:

<a href="/Home/About">About MVC</a>

HTML Form Elements

*Html.BeginForm() *Html.CheckBox() *Html.DropDownList() *Html.EndForm()

*Html.Hidden() *Html.ListBox() *Html.Password() *Html.RadioButton() *Html.TextArea()

*Html.TextBox()

@Html.ValidationSummary("Create was unsuccessful. Please correct the

errors and try again.")

@using (Html.BeginForm()){

<p>

<label for="FirstName">First Name:</label>

@Html.TextBox("FirstName")

@Html.ValidationMessage("FirstName", "*")

</p>

<p>

<label for="LastName">Last Name:</label>

@Html.TextBox("LastName")

@Html.ValidationMessage("LastName", "*")

</p>

<p>

<label for="gender">Gender:</label>

@Html.RadioButton("gender", "Male", true) Male

@Html.RadioButton("gender", "Female", false) Female

</p>

<p>

<label for="Password">Password:</label>

@Html.Password("Password")

@Html.ValidationMessage("Password", "*")

</p>

<p>

<label for="Password">Confirm Password:</label>

@Html.Password("ConfirmPassword")

@Html.ValidationMessage("ConfirmPassword", "*")

</p>

<p>

<label for="Profile">Profile:</label>

Action Link

Action Link helper method is used to link to an action method.

Syntax of ActionLinkHelper method

@Html.ActionLink("Show list", "Index", "Country")

it links to 'Index' method in 'CountryController'.

Output the following HTML

<a href="Country/Index">Show list</a>

Begin Form - BeginForm helper class help to POST the form content to action method.

Syntax of BeginForm Helper method

@using (Html.BeginForm("AddDetails", "Home", FormMethod.Post, new

{ enctype = "multipart/form-data" }))

{ -----Form Content-----}


<form action="Home/AddDetails" method=POST>

Radio Button Syntax of Radio Button Helper method

@Html.RadioButton("gender", "Male", true) Male

@Html.RadioButton("gender", "Female", false) Female


<input type="radio" value="Male" name="gender" />Male

<input type="radio" value="Female" name="gender" />Female

Check Box Helper

Syntax of Razor CheckBox helper

@Html.CheckBox("ReceiveNewsletter")I agree

Output the HTML

<input type="checkbox" name="ReceiveNewsletter" />I agree

ViewBag - 'ViewBag' and 'ViewData' have the same functionalities.It can store data.ViewBag is

used to pass data from controller to view

The action method contain

List color = new List();

color.Add("blue");

color.Add("green");

color.Add("red");

ViewBag.Colors= color;

ViewBag.name = "ABC";

ViewBag.age = 25;

The View contains

My name is

@ViewBag.name

Age:@ViewBag.age

Color:@Html.DropDownList("Colors")

Default Home Controller -When we start to create a new project,a default home controller with

Index(),About() action method will provided.

HomeController

using System;


using System.Linq;

using System.Web;



{ public class HomeController : Controller


{ ViewBag.Message = "Welcome to ASP.NET MVC!";

return View(); }

public ActionResult About()

{ return View(); } }}

Master Pages In ASP .NET MVC or Using Layout For Common Site Elemnts

Layout for Common site Elements

Layout page is used to add some common site elements.

Go to Views>>Shared>>_Layout.cshtml

<!DOCTYPE html>

<html>

<head>

<title>@ViewBag.Title</title>

<link href="@Url.Content("~/Content/Site.css")" rel="stylesheet"

type="text/css" />

<script src="@Url.Content("~/Scripts/jquery-1.5.1.min.js")"

type="text/javascript"></script>

</head>

<body>

<div class="page">

<div id="header">

<div id="title">

<h1>My MVC Application</h1>

</div>

<div id="logindisplay">

@Html.Partial("_LogOnPartial")

</div>

<div id="menucontainer">

<ul id="menu">

<li>@Html.ActionLink("Home", "Index", "Home")</li>

<li>@Html.ActionLink("About", "About", "Home")</li>

</ul>

</div>

</div>

<div id="main">

@RenderBody()

</div>

<div id="footer">

</div>

</div>

</body>

</html>

Run the default project...

Change the layout page according to our needs..Suppose we want another link,'Contact us' ... add

the following code in _Layout.cshtml..

<li>@Html.ActionLink("Contact us", "Contact", "Home")</li>

Add Home controller action method(Contact()) and View for that action method.Then run the project.

Next change the heading My MVC Application to New Project

Introduction to DbContext and DbSet

DbContext :Simplfied alternative to ObjectContext and is the primary object for interacting with a

database using a specific model.

DbSet : Simplified alternative to ObjectSet and is used to perform CRUD operations against a

specific type from the model.

DbContext and DbSet is used for the CodeFirst appraoch.Which enables a very clean and rapid

development workflow.

Suppose we want to create a database called 'NewDatabase' and two tables in that called 'State'

and 'Country'.Then write the Model classes..

Goto Models rigtht click on Models>>Add>>Class

Add a model class and name it as Country.cs.

using System;


using System.Linq;

using System.Text;

using System.ComponentModel.DataAnnotations;

namespace MvcApplication2.Models

{

public class Country

{ [Key]

public virtual int country_id {get; set; }

[Required ]

public virtual string country_name { get; set;} }}

Similarly add another class and named it as State.cs.

using System;


using System.Linq;

using System.Text;



{ public class State

{ [Key]

public virtual int state_id {get; set; }

[Required ]

public virtual string state_name { get; set;} }}

Add another Model class 'NewDatabase.cs'

using System;


using System.Linq;

using System.Web;

using System.Data.Entity;


{ public class NewDatabase:DbContext

{

public DbSet Country { get; set; }

public DbSet State { get; set; } }}

Goto HomeController

Goto Views>>Index.cshtml

Accessing Models Data from Controller

The below given example shows how to acces Models Data from Controller.

Create new project,add Context class 'NewDatabase.cs' and Model class 'Country.cs'

NewDatabase.cs

using System;


using System.Linq;

using System.Web;

using System.Data.Entity;


{ public class NewDatabase:DbContext

{ public DbSet<country>Country { get; set; } }}

Country.cs

using System;


using System.Linq;

using System.Text;



{ public class Country

{ [Key]

public virtual int country_id {get; set; }

[Required ]

public virtual string country_name { get; set;} }}

Add a Controller 'CountryController'

CountryController.cs

using System;


using System.Linq;

using System.Web;


using MvcApplication2.Models;


{ public class CountryController : Controller

{ // // GET: /Country/

NewDatabase db = new NewDatabase();

public ActionResult Index()

{ //Shows Country details

var model = db.Country;

return View(model); }

public ActionResult AddCountry()

{ return View(); }

[HttpPost]

public ActionResult AddCountry(Country model)

{

// Attempt to add the country name

db.Country.Add(model);

db.SaveChanges();

return View(model); } }}

Run the Project

Using a Model to pass data to our View

Basically a view template is an HTML output for viewers,if we want to create dynamic web pages we

need to pass informations from controller to views.Model class represents to the tables in our

database and Model classes can be used to access database values,these Model data passes to

views to create webpages,that is done by the controller.

Let us go through the example....

Create Context class 'Newdatabase' and model class for representing Country table in our database,

'Country.cs' as explained earlier in Accessing Model Data From Controller

Add ActionMethod in CountryController...

public ActionResult countryDetails(int id)

{ Country country = db.Country.Find(id);

return View(country); }

Add a View for the action method..Right Click inside 'countryDetails' >>Add View

http://mvc4beginner.com/Tutorial/ASP-.NET-MVC-Accessing-Models-Data-From-Controller.html

countryDetails.cs

@model MvcApplication2.Models.Country

@{ ViewBag.Title = "countryDetails";}

<h2>countryDetails</h2>

Country name: @Html.DisplayFor(model => model.country_name)

Run the project with Url: ../Country/countryDetails/1

Changing Views and Layout

We can change the Layout page and view page of our project.

Let us start with an example....Create a new project,named it as 'Countries'.

The default project will run like this..

We want to change the heading 'My Mvc Application' which is common to all pages to 'Country Lists'

Goto Views>>Shared>>_Layout.cshtml

Change the title to 'Country Lists'

run the project

Change the Content....

Run the project to see the changes...

to Change the message 'Welcome to ASP.NET MVC'..,Goto HomeController>>Index method

Change the ViewBag Data.

Partial Views

A partial view enables you to define a view that will be rendered inside a parent view. Partial views

are implemented as ASP.NET user controls (.ascx).

When a partial view is instantiated, it gets its own copy of the ViewDataDictionary object that is

available to the parent view. The partial view therefore has access to the data of the parent view.

However, if the partial view updates the data, those updates affect only the partial view's ViewData

object. The parent view's data is not changed. By using partial view we can render a view inside a

parental view and to create reusable content in the project.

Go through the given example .Create a Model class for partial view named it as 'PartialModel2.cs'

PartialModel2.cs

using System;


using System.Linq;

using System.Web;


{ public partial class PartialModel2

{ public string Name { get; set; }

public int Age { get; set; }

public string Address { get; set; } }

public partial class PartialModel2

{ public List<PartialModel2> partialModel { get; set; } }}

Add the following methods in HomeController.

HomeController.cs

using System;


using System.Linq;

using System.Web;


using MvcApplication2.Models;


{ public class HomeController : Controller


{

ViewBag.Message = "Welcome to ASP.NET MVC!";

return View(new PartialModel2() { partialModel =

Sampledetails() });

}

private List<partialmodel2> Sampledetails()

{ List<partialmodel2> model = new List<partialmodel2>();

model.Add(new PartialModel2()

{ Name = "Rima", Age = 20, Address="Kannur" });


{ Name = "Rohan", Age = 23, Address = "Ernakulam" });


{Name = "Reshma", Age = 22, Address = "Kannur" });

return model; } }}

Add Partial View

Views>>Right click on 'Home'>>Add>>View

Name the View as'PartialView1' and Check on the checkbox 'Create as a partial view',the click on

'Add' button.

PartialView1.cshtml

@model IEnumerable<MvcApplication2.Models.PartialModel2 >

@using MvcApplication2.Models

@if (Model != null)

{ <div class="grid">

<table cellspacing="0" width="80%">

<thead> <tr> <th>Name </th> <th>Age</th>

<th>Address</th>

</tr>

</thead>

<tbody>

@foreach (var item in Model)

{

<tr>

<td align="left">

@item.Name

</td>

<td align="left">

@item.Age

</td>

<td align="left">

@item.Address

</td> </tr>}</tbody></table></div>}

Render the partial view into Index(parental) view.

Index.cshtml

@model MvcApplication2 .Models.PartialModel2

@{ ViewBag.Title = "Home Page";}

<p> <div>@Html.Partial("PartialView1", Model.partialModel) </div></p>

Run the project

MVC ViewDataDictionary Represents a container that is used to pass data between a controller and a view.

Accessing Data From View to Controller

The Properties of the ViewDataDictrionary are

> Count | Gets the number of elements in the collection.

> IsReadOnly

> Item

> Keys

> Model | Gets or sets the model that is associated with the view data.

> ModelMetadata

> ModelState

> TemplateInfo

> Values | Gets a collection that contains the values in this dictionary.

Request.Form[“CountryCode”]

NonActionAttribute in mvc

Partial View

MVC Helper

Passing Data Between Action Methods

MVC ActionFilter Like [Authozie]

By default mvc treats all public methods in a controller as action methods. U can mark some

of the methods as non action methods using the NonActionAttribute attribute.Eg.

[NonAction]

private void DoSomething()

{

}

> Action Methods might have to pass data to another action.

> An action method can store data in the controller's TempDataDictionary object

before it calls the controller's RedirectToAction method to invoke the next action.

The TempData property value is stored in session state. Any action method that is

called after the TempDataDictionary value is set can get values from the object and

then process or display them. The value of TempData persists until it is read or

until the session times out. Persisting TempData in this way enables scenarios

such as redirection, because the values in TempData are available beyond a single

request.

How to publish the mvc solution u have created to a website

HTML Helpers

> Html.Raw

TagBuilder

Helper MVCHtmlString

When u want to return non htmlencoded helpers

PartialView

Html.Action

[ChildActionOnly]

DefaultModelBinder

JQuery

JQuery is a javascript library .Is used to add client side features to the application.

JqueryUI

Is a jquery Plugin

This library includes a number of animation effects, Widgets Like Dialogs , Sliders,

Accordians, Tabs, Autocomplete,

UnObtrusive Javascript

Custom Action Filters

Create a Class . Eg HelloWorldAttribute

Derieve it from Action Filter Attribute

Override Methods Like ActionExecuting, ActionExecuted etc .

[HelloWorld] can be given controller wide or for an Action Method

To Make it effective application wide. Open global.asax.cx and add filters.add(new

HellowWorldAttribute() ); in the Register Global Filters

This can be used logging .

View Where Data is rendred from different action Methods

http://muruganad.com/ASP.NET/MVC/Create-Mvc-view-by-rendering-data-from-differenet-

action-methods.html

1. Build the solution.

2. Right click on the project in Solution Explorer . Select Publish option.

3. if the webserver doesnot have MVC installed, copy the folloing dlls to the bin folder of your

website before building the solution.

dlls to be copied to the bin folder:

a. System.Web.MVC.dll

b. System.Web.Routing.dll c. System.Web.Extensions.dll

The dlls can be found by checking the physical folder path of these dlls in the reference

folder.

do the steps 1 and 2 above.

Copy the files from the Publish folder to the destination folder on your website.

MVC Get Dropdown Selected Text

asp .net mvc populate a dropdownlist from DataSet

LIST OF ATTRIBUTES

1. ActionMethodSelectorAttribute

2. ActionNameAttribute

3. ActionNameSelectorAttribute : Represents an attribute that affects the

selection of an action method.

4. AllowHtmlAttribute : Allows a request to include HTML markup during

model binding by skipping request validation for the property. (It is

strongly recommended that your application explicitly check all models

where you disable request validation in order to prevent script

exploits.)

5. AllowAnonymousAttribute : Represents an attribute that marks

controllers and actions to skip the AuthorizeAttribute during

authorization.

6. AuthorizeAttribute : Represents an attribute that is used to restrict

access by callers to an action method.

7. BindAttribute : Represents an attribute that is used to provide

details about how model binding to a parameter should occur.

There is no way to directly get value from a Html.DropDownList .

The alternative is to make a hidden fieled. thats get populated by javascript

on click of a button or selectedindex change of dropdownlist.

// Controller CODE.

List list = new List { };

foreach(DataRow oDataRow in oCountry.DataSetCountry.Tables[0].Rows)

{

SelectListItem oSelectListItem = new SelectListItem { Value =

(String)oDataRow["CountryCode"],Text = (String)oDataRow["CountryName"]};

list.Add(oSelectListItem);

}

ViewData["DDLCountry"] = list;

8. ChildActionOnlyAttribute : Represents an attribute that is used to

indicate that an action method should be called only as a child action.

9. CompareAttribute : Provides an attribute that compares two properties

of a model.

10. CustomModelBinderAttribute : Represents an attribute that invokes a

custom model binder.

11. FilterAttribute : Represents the base class for action and result

filter attributes.

System.Object

System.Attribute

System.Web.Mvc.FilterAttribute

System.Web.Mvc.ActionFilterAttribute

System.Web.Mvc.AuthorizeAttribute

System.Web.Mvc.ChildActionOnlyAttribute

System.Web.Mvc.HandleErrorAttribute

System.Web.Mvc.RequireHttpsAttribute

System.Web.Mvc.ValidateAntiForgeryTokenAttribute

System.Web.Mvc.ValidateInputAttribute

12. HandleErrorAttribute : Represents an attribute that is used to handle

an exception that is thrown by an action method.

13. HiddenInputAttribute : Represents an attribute that is used to

indicate whether a property or field value should be rendered as a hidden

input element.

14. HttpDeleteAttribute : Represents an attribute that is used to

restrict an action method so that the method handles only HTTP DELETE

requests.

15. HttpGetAttribute : Represents an attribute that is used to restrict

an action method so that the method handles only HTTP GET requests.

16. HttpHeadAttribute : Specifies that the HTTP request must be the HTTP

HEAD method.

17. HttpOptionsAttribute : Represents an attribute that is used to

restrict an action method so that the method handles only HTTP OPTIONS

requests.

18, HttpPatchAttribute : Represents an attribute that is used to restrict

an action method so that the method handles only HTTP PATCH requests.

19. HttpPostAttribute : Represents an attribute that is used to restrict

an action method so that the method handles only HTTP POST requests.

20. HttpPutAttribute : Represents an attribute that is used to restrict

an action method so that the method handles only HTTP PUT requests.

21. ModelBinderAttribute : Represents an attribute that is used to

associate a model type to a model-builder type.

22. NoAsyncTimeoutAttribute : Provides a convenience wrapper for the

AsyncTimeoutAttribute attribute.

23. NonActionAttribute : Represents an attribute that is used to indicate

that a controller method is not an action method.

24. OutputCacheAttribute : Represents an attribute that is used to mark

an action method whose output will be cached.

25. RemoteAttribute : Provides an attribute that uses the jQuery

validation plug-in remote validator.

26. RequireHttpsAttribute : Represents an attribute that forces an

unsecured HTTP request to be re-sent over HTTPS.

27. SessionStateAttribute : Specifies the session state of the

controller.

28. ValidateInputAttribute : Represents an attribute that is used to mark

action methods whose input must be validated.

You can write your own attributes by directly or indirectly inheriting from System.Attribute .

For example you can see sample below where MyAFActionFilters in herits ActionFilterAttribute

which again is inherited. Shown Below Inheritance Chain.

System.Attribute

System.Web.Mvc.FilterAttribute

System.Web.Mvc.ActionFilterAttribute

MyAFActionFilters : ActionFilterAttribute

Action Filters are used in cases where we need to perform some logic either before an action

method is called or after an action method runs.

Action Filters : How to use them

Action Filters can be applied to a controller action or an entire controller. The Best known example of

an action filter is the [Authorize] Attribute.

LIST OF ACTION FILTERS

1. OutputCache : This action filter caches the output of a controller

action for a specified amount of time.

2. HandleError : This action filter handles errors raised when a

controller action executes.

3. Authorize : This action filter enables you to restrict access to a

particular user or role.

Action Filters : How to create an Action Filter Filters are custom classes that provide both a declarative and programmatic means to add pre-

action and post-action behavior to controller action methods.

Types of Action Filters

1. Authorization filters Implements the IAuthorizationFilter attribute.

This filter is always executed first.

2. Action filters Implements the IActionFilter attribute.You can use

this filter to modify the viewdata that an action returns.

3. Result filters Implements the IResultFilter attribute. Eg You might

want to modify the view result before view is redered to the browser.

4. Exception filters Implements the IExceptionFilter attribute. Can be

used to log errors, raised by your controller action or controller action

results

Action Filters : Code Sample Writing an Action filter is very simple. All you need is to create a class with Name

WhatEverNameActionFilter

Inherit ActionFilterAttribute class override the action methods and you are done.

using System;


using System.Linq;

using System.Web;


using System.Web.Routing;

using System.Diagnostics;

namespace CampusIndya.Models

{ public class MyAFActionFilters : ActionFilterAttribute

{ public override void OnActionExecuted(ActionExecutedContext

filterContext)

{ MyAF("OnActionExecuting",

filterContext.RouteData); }

public override void OnActionExecuting(ActionExecutingContext

filterContext)

{ base.OnActionExecuting(filterContext); }

public override void OnResultExecuted(ResultExecutedContext

filterContext)

{ base.OnResultExecuted(filterContext); }

public override void OnResultExecuting(ResultExecutingContext

filterContext)

{ base.OnResultExecuting(filterContext); }

private void MyAF(string methodName, RouteData routeData)

{ var controllerName = routeData.Values["controller"];

var actionName = routeData.Values["action"];

var message = String.Format("{0} controller:{1} action:{2}",

methodName, controllerName, actionName);

Debug.WriteLine(message, "Action Filter Log"); } }}

You can see that in the Solution Explorer the Visual Studio has created some files and folders

Application Information Properties :

References :

Application Folders

App_Data Folder : Used for storing application data

Content Folder : Used for storing static files like

stylesheets icons & images

Scripts Folder : Put the javascript files in here.

By default it contains mvc , ajax &

jquery files.

Models Folder : Contains a Folder for every Controller,

its used to store the view (.cshtml)

files

Views Folder : Contains Model Class which represent

the application models.Model Classes

are used for data manipulation

Controllers Folder : Contains Controller Class which is

responsible for handling user input

and responses

Configuration Files

Global.asax : Its an optional file, This is where u

write logic at the application leavel

or define objects with session or

application

wide scope . Example of practical use

Eg. "Error Handling" .

You can define event handlers in the

application wide or session wide scope.

Packages.confuguration :

Web.config :

Request Flow handles the request from the user ( client ) and send it to the server. Lets look into

details on the function flow internally when client raises a request. This is what happens when u type

an asp .net mvc application URL into the address bar of a web browser & clicks on enter.

Request -->Routing --> Handler -->Controller --> Action --> View --> Response

Detailed Look at the Request Flow

1. Request comes into ASP.NET

2. ASP.NET Routing finds the route match by calling

RouteCollection.GetRouteData

3. This in turn calls RouteBase.GetRouteData on each route until it

finds a match

4. The IRouteHandler for the matching route has its GetHttpHandler

method called

5. The MvcHandler runs (ProcessRequest is called)

6. The MVC controller factory locates and creates the controller in

CreateController

7. The ControllerActionInvoker determines which action to run in

InvokeAction

8. The AuthorizationFilter stage executes (this includes the

authorization method on the controller itself)

9. The ActionExecuting stage executes

10. The requested action method is executed

11. The ActionExecuted stage executes

12. If there is a result object then the ResultExecuting stage executes

13. If the result wasn't cancelled then the ActionResult's

ExecuteResult method is executed

14. The ResultExecuted stage executes

15. If an error occured then the Exception stage executes

Let Look at the Errors

Since the return type is View MVC Does the Following

-> Check to see in the Views -> Home ( Controller Name ) -> Index.aspx,

ascx

( Index is the Action Method Name , Note : if the action methods name

is

hello it would search for hello.aspx)

-> After Checking in the View's Home Folder For Action Method.aspx it

searches the shared folders for view named index.ascx

-> It searches for .cshtml or vbhtml file types in views->controller

folder

followed views->shared

-> finally if the actionmethod.ascx in this case index.ascx is not found

it thows an error like above.

-> the solution to solve the error is simple, just add a vew for the

Controlelrs Action Method

Creating the barebone hello world application with only the routing & controller helps to learn whats

the bare minimum thats required to run an mvc application.

Step 1 : Create A New Project Step 2 : Delete All Selected Files Except Configutatoin ( Global.asax, Web.Config & Packages.Config ) Step 3 : Add New Folder "Controllers"

Step 4 : Add New Controller : "Home Controller"

Step 4 : Change return type to Content

Run the application

The Above Program is the smallest or a breabone program you can write which outputs some text.

As you can see this program has only the Controller and has NO View or Models

NOW A PROGRAM WITH ONLY CONTROLLER & VIEW

Step 1 : Change Return Type to View & Run the Program

Let Look at the Errors

Since the return type is View MVC Does the Following

-> Check to see in the Views -> Home ( Controller Name ) -> Index.aspx,

ascx

( Index is the Action Method Name , Note : if the action methods name

is

hello it would search for hello.aspx)

-> After Checking in the View's Home Folder For Action Method.aspx it

searches the shared folders for view named index.ascx

-> It searches for .cshtml or vbhtml file types in views->controller

folder

followed views->shared

-> finally if the actionmethod.ascx in this case index.ascx is not found

it thows an error like above.

-> the solution to solve the error is simple, just add a vew for the

Controlelrs Action Method

Step 2 : Add A View Page

To do this right click on the action method index

Uncheck everything & Click on add

In the newly careted page . add text to display as shown above

Step 3 : Run the application

Step 4: Modify the program by Passing Data From Controller To View

Step 5 : Run the application

The Above Program is the smallest or a breabone program you can write which outputs some text. As you can see this program has only the Controller and has NO View or Models

NOW A PROGRAM WITH ONE MORE ELEMENT MODEL to create Your Model View Controller Application

Step 1 : Add New Folder ModelsStep 2 : Add New Model Named CountryStep 3 : Add Properties Country Code & Country NameStep 4 : Home Controller Create an Instance of Country , populate data and pass it in ViewStep 5 : Create A Strongly Typed View

We will delete the index in view file as it already exist else it will theow an already exist error

Step 5 : Modify View to Display the object value & Run the application

This is your barebone Hello World Controller Application

LETS MODIFY THE PROGRAM TO DISPLAY A LIST OF COUNTRIES

Step 1 : Modify the Home Controller so that we can data of type List to the ViewStep 2 : Delete Existing Index View & Create A New Stronly Typed View With A Scaffold Template type ListStep 3 : Run the Application Step 4 :Clean Up The View A Bit : Delete SelectedStep 5 : Run the Application

There are different Scaffold Template Types you can use to create the view, This would emilinate the need for us having to write HTML. You can expirement with different Template types.The ASP.NET Routing module is responsible for mapping incoming browser requests to particular MVC controller actions.

ASP .NET Routing is setup in two places

Web.Config : ASP .NET Routing is enabled in your web.config file

There are 4 sections in the configuratio file that

are relavent to routing

1. system.web.httpModules section

2. system.web.httpHandlers section

3. system.webserver.modules section

4. system.webserver.handlers section.

Note : Without the above sections the routing will not work, do donot

delete them.

Global.asax : This is a file which contain event handlers for

application life cycle events.

for A Route table is created in the application's global.asax file, which

is created during the applications start event.

Exploring the Global.asax file

In the application Application_Start function we can see a call to RegisterRoutes

You can see a default route map in the figure.

The Route name could be anything unique.

There is a predefined route map which maps to Controller/Action/id

When you add additional routes kindly remember that the order is importnat, they neededs to be

added on top of the default route.

We will add a New Route Search

The Above Route Search/ID maps to Controller = Home/ Action Method = Search / ID

Add Action Method Search To Home Controller

Run the Application

You can define your own custom routes. Remember that the order is important as the the first route

that satisfys the condition is called.

Entity Framrwork ( EF ) is an object relational mapper that enables .Net developers to work with

relational data. It eliminates the need for most of the data access code that the developers need to

write.

What is Entity Framework ?

ADO.NET Entity Framework (EF) is an open source object-relational mapping (ORM) framework for

the .NET Framework.In EF developers work with the data in terms of class, objects and properties

and forget about the underlying database tables & coloumns. In the example code I will show you

how database its tables & coloumns is generated from objects in code. Goal is to reduce the amount

of code and data mantinance for data centric applications.

ADVANTAGES

1. Development with EF is fast and streamlined

2. Less coding required to accomplish complex tasks

3. Database Independant (Free from hardcoded dependencies on a

particular data engine or storage schema)

4. Extensible

5. Mappings between the conceptual model and the storage-specific schema

can change without changing the application code.

6. Developers can work with a consistent application object model that

can be mapped to various storage schemas, possibly implemented in

different database management systems.

7. Multiple conceptual models can be mapped to a single storage schema.

8. Language-integrated query (LINQ) support provides compile-time

syntax validation for queries against a conceptual model.

Entity Framework Architecture

Documents

Mvc