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ASP.NET MVC Hosting - HostForLIFE.eu :: ASP.NET MVC 5 Create Shared Razor Layout And ViewStart

clock October 25, 2019 09:18 by author Peter

In article, I have shared a way to create a Layout Razor and ViewStart in ASP.NET MVC 5.
 
Views/Shared
You need to create a shared folder, "Shared" in the Views directory.
 
Go Views/Shared directory and create new _LayoutPage1.cshtml file and write the following below code.
    <!DOCTYPE html> 
     
    <html> 
    <head> 
        <meta name="viewport" content="width=device-width" /> 
        <title>@ViewBag.Title</title> 
    </head> 
    <body> 
        <div> 
            @RenderBody() 
        </div> 
    </body> 
    </html> 


The @RenderBody()
Use display content in multiple controllers to View.

Example you can have a fixed header and footer in the page. Only change will be the content of the RenderBody() called in the code.
    <html> 
    <head> 
        <meta name="viewport" content="width=device-width" /> 
        <title>@ViewBag.Title</title> 
    </head> 
    <body> 
        <div class="header"> 
            <!--code header fixed--> 
        </div> 
        <div> 
            @RenderBody() 
        </div> 
        <div class="footer"> 
            <!--code footer fixed--> 
        </div> 
    </body> 
    </html> 


So you have fixed the (header/footer) for the website.
 
Okay, you need using _LayoutPage1.cshtml, so you to Views/Home/index.cshtml. Open it, pass the following below code.
    @{ 
        ViewBag.Title = "Index"; 
        Layout = "~/Views/Shared/_LayoutPage1.cshtml"; 
    } 


_ViewStart.cshtml used to define the layout for the website. You can set the layout settings as well, if HomeController is using Layout.
 
_LayoutHome.cshtml or AdminController is _LayoutAdmin.cshtml
    //Views/ViewStart.cshtml 
    @{ 
        Layout = "~/Views/Shared/_LayoutPage1.cshtml"; 
    } 


You can configuration _ViewStart.cshtml the following below code.
    @{ 
     
        string CurrentName = Convert.ToString(HttpContext.Current.Request.RequestContext.RouteData.Values["Controller"]); 
        string clayout = ""; 
        switch (CurrentName) 
        { 
            case "Home": 
                clayout = "~/Views/Shared/_LayoutHome.cshtml"; 
                break; 
            default: 
                //Admin layout   
                clayout = "~/Views/Shared/_LayoutAdmin.cshtml"; 
                break; 
        } 
        Layout = clayout; 
     
    } 

This gives you an idea, how to use a Razor layout in various pages.

 



ASP.NET MVC Hosting - HostForLIFE.eu :: Preventing Cross Site Request Forgery In MVC

clock September 26, 2019 11:14 by author Peter

What is Cross-Site Request Forgery
Cross-Site Request Forgery (CSRF) is a process in which a user first signs on to a genuine website (e.g. facebook.com) and after successful login, the user opens another website (malicious website) in the same browser.
 
Both websites are opened in the same browser. Malicious website will display some links to the user and asks the user to click on those links. User clicks on the links displayed on a malicious website, the malicious website sends a request using the existing session of genuine website. Web server of genuine website treats this request as a valid request and assumes that it is coming from a valid user so it executes the request and provides a proper response. A malicious website can perform harmful operations on genuine website.
 
In order to solve this problem, we expect the Action Method of genuine website to recognize the source of the request, whether the request is coming from genuine website or from a malicious website. This can be achieved by using the [ValidateAntiForgeryToken] attribute in ASP.Net MVC.
 
How to Implement CSRF Security in MVC
In order to implement CSRF security in MVC, first, we need to use HTML helper @Html.AntiForgeryToken() in view. It should be placed inside the BeginForm() method in view.
 
Next, we need to add [ValidateAntiForgeryToken] attribute on the action method which will accept HTTP post request. We need to do only these 2 changes and now MVC will prevent CSRF attacks.
 
How ValidateAntiForgeryToken works
How ValidateAntiForgeryToken prevents CSRF attacks?


First, the user will open genuine website in the browser. User login to genuine website. After login, genuine website sends Authentication cookie and Verification token. Verification token has randomly generated alphanumeric values. The verification token is stored in the cookie as well as in hidden field on client-side. When HTML form is submitted to the server, the verification token is submitted as a cookie as well as a hidden field. On the server-side, both are checked if they are same or not? If both are same then request is valid. If they are different or one of them is missing then request is treated as invalid request and will be rejected automatically by MVC.
 
When a user opens a malicious website in a new tab of the same browser, the malicious website will display some links and ask the user to click on those links. This website already has a script to send the request to genuine website. When the user clicks on links, the malicious website sends a request to genuine website. Since request is being sent to genuine website, the browser automatically submits Authentication cookie to Action method of genuine website but here, the hidden field is missing. The Action method has [ValidateAntiForgeryToken] attribute so it checks whether Authentication cookie and hidden field has same value but here, the hidden field is missing so the request is treated as invalid and it is rejected by MVC.
 
Practical Implementation
Wherever you have a Form, use @Html.AntiForgeryToken() inside the form and action method for accepting the HTTP Post should have ValidateAntiForgeryToken attribute. These are the only change, the rest of the process will be taken care of by ASP.Net MVC.
 
Please see the below HTML view where I have added@Html.AntiForgeryToken()
    @using (Html.BeginForm("Create", "Products", FormMethod.Post, new { enctype = "multipart/form-data" })) 
    { 
       @Html.AntiForgeryToken() 
       <div class="form-row"> 
       <div class="form-group col-md-6"> 
          @Html.LabelFor(temp => temp.ProductName) 
          @Html.TextBoxFor(temp => temp.ProductName, new { placeholder = "Product Name", @class = "form-control" }) 
          @Html.ValidationMessageFor(temp => temp.ProductName) 
       </div> 
    <div class="form-group col-md-6"> 
       @Html.LabelFor(temp=>temp.Price) 
       @Html.TextBoxFor(temp=>temp.Price,new { @class="form-control",placeholder="Price"}) 
    </div> 
    </div> 
    @Html.ValidationSummary() 
       <button type="submit" class="btn btn-success">Create</button> 
       <a class="btn btn-danger" href="/products/index">Cancel</a> 
    } 

Below is the action method where I have added [ValidateAntiForgeryToken] attribute.
    [HttpPost] 
    [ValidateAntiForgeryToken] 
    public ActionResult Create(Product p) 
       { 
       ProductDBContext db = new ProductDBContext(); 
       if (ModelState.IsValid) 
       { 
          db.Products.Add(p); 
          db.SaveChanges(); 
          return RedirectToAction("Index"); 
       } 
       else 
       { 
          return View(); 
    } 
    } 

Summary
In this blog, I have explained Cross-Site Request Forgery(CSRF), its steps and what changes we need to do in MVC application to prevent CSRF attacks.



ASP.NET MVC 5 Hosting - HostForLIFE.eu :: Bootstrap Tab Strip in ASP.NET MVC

clock September 18, 2019 12:47 by author Peter

In this post, we will see how to render given below bootstrap Tab script in Asp.net MVC 5 view.

Here the number of tabs displayed in view would depend on count of members in the list.

1. Create ASP.NET MVC 5 project.
 
2. Define Member class as follows in “Member.cs” file
    public class Member 
    { 
    public int Id { get; set; } 
    public string Name { get; set; } 
    } 

3. Add view to create action method and pass a list of members from controller Action method to razor view file. i.e. “create.cshtml”
    public ActionResult Create() 
    { 
    List<Member> members = new List<Member>(); 
    members = GetMemberList(); 
    return View(members); 
    } 
    private List<Member> GetMemberList() 
    { 
    List<Member> members = new List<Member>(); 
    members.Add(new Member{ Name = "member1" }); 
    members.Add(new Member { Name = "member2" }); 
    members.Add(new Member { Name = "member3" }); 
    members.Add(new Member { Name = "member4" }); 
    members.Add(new Member { Name = "member5" }); 
    return members; 
    } 


4. Using CSS classes, we can create a tabscript in our “create.cshtml” as shown below:
    @model IEnumerable<Member> 
    <div class="container"> 
    @if (Model.ToList().Count > 0) 
    { 
    <ul class="nav nav-tabs" role="tablist"> 
    @{int i = 0; 
    foreach (var item in Model) 
    { 
    if (i == 0) 
    { 
    <li class="nav-item"> 
    <a class="nav-link active" data-toggle="tab" href="#@item.Name">@item.Name</a> 
    </li> 
    } 
    else 
    { 
    <li class="nav-item"> 
    <a class="nav-link" data-toggle="tab" href="#@item.Name">@item.Name</a> 
    </li> 
    } 
    i++; 
    } 
    } 
    </ul> 
    <div class="tab-content"> 
    @foreach (var item in Model) 
    { 
    <div id="@item.Name" class="container tab-pane active"> 
    <br> 
    <h3>@item.Name 's Tab Area </h3> 
    </div> 
    } 
    </div> 
    } 
    </div> 
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js"></script> 
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.7/umd/popper.min.js"></script> 
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.3.1/js/bootstrap.min.js"></script> 



ASP.NET MVC 5 Hosting - HostForLIFE.eu :: Friendly Errors In MVC 5

clock July 20, 2018 08:51 by author Peter

In this article, I will be explaining 3 different ways to handle exceptions and display a friendly error page to the end user. Friendly Error Pages are the pages that you design to show the end user when any kind of not handled exception happens in your application and your expected result is not achieved. So, instead of presenting your end user with technical information regarding the exception, you show him a friend page. Also, presenting your end user with technical information is not a security best practice.

So, let's see the three ways.

Method 1: Custom Exception Filter
Custom Exception Filter

It is a filter that is called every time an exception occurs in the applied methods.

Why would I use a custom exception filter?


Because with a custom exception filter, you can handle in a generic way every kind of exception thrown by your actions and/or controllers. You may use custom exception filters to log your exceptions.

Steps to achieve this:
Step 1

Create a new class named CustomExceptionFilter.
public class CustomExceptionFilter : FilterAttribute, IExceptionFilter   
{   
    public void OnException( ExceptionContext filterContext )   
    {   
        filterContext.Result = new RedirectResult( "Home/About" );   
        filterContext.ExceptionHandled = true;   
    }   
}   

What this custom exception does is to redirect to your About action in your Home Controller. Do not forget to set the ExceptionHandled equal to true; otherwise it will not take effect.

Step 2
Apply your custom exception filter to your controller/action.
public class HomeController : Controller 

    [CustomExceptionFilter] 
    public ActionResult Index() 
    { 
        throw new Exception(); 
        return View(); 
    } 
 
    public ActionResult About() 
    { 
        ViewBag.Message = "Your application thrown an exception"; 
 
        return View(); 
    } 
 
    public ActionResult Contact() 
    { 
        ViewBag.Message = "Your contact page."; 
        throw new Exception(); 
        return View(); 
    } 


You can see that the exception filter is applied only to your Index Action so if you access your Contact action, you will be able to see the non-handled exception page.

Method 2: Web.Config configuration
Why would I handle an exception by web.config configuration?

It is easy to configure and useful when you do not need to log or work on the exception.

Steps to achieve this:

Step 1
Include this in your web.config inside the system.web tag.
<customErrors defaultRedirect="Error.cshtml" mode="On"></customErrors> 

Step 2
Update your Controller.
public class HomeController : Controller 

    [HandleError] 
    public ActionResult Index() 
    { 
        throw new Exception(); 
        return View(); 
    } 
 
    public ActionResult About() 
    { 
        ViewBag.Message = "Your application description page."; 
 
        return View(); 
    } 
 
    public ActionResult Contact() 
    { 
        ViewBag.Message = "Your contact page."; 
        throw new Exception();
        return View(); 
    } 


Observation - Like the custom exception filter, you may choose if you want to handle the exceptions at the Controller or Action level. Also, here, the handled exception is applied only to your Index action, you may see the non-handled error in the Contact View.

Method 3: Global.Asax Application_error
What is the Application_error?

It is to override the global exception handler of the application.

Why would I handle an exception by global.asax Application_error?
You do not need to set the places that you would like to handle the errors like before where you had to set the actions and controllers to be handled. Here, every exception will hit and be handled.

Steps to Achieve this:

Step 1
Update  your global.asax.
protected void Application_Error( object sender, EventArgs e ) 
  { 
      Exception exception = Server.GetLastError(); 
      Server.ClearError(); 
      Response.Redirect( "/Home/About" ); 
  } 


Like the custom exception handlers, it is very important to ClearError() in the Server. What is done here is the redirection of non-handled exceptions to the About action in the Home Controller. Congratulation, you just learned three good ways of handling exceptions in your application and presenting friendly error pages to your end users.



ASP.NET MVC 5 Hosting - HostForLIFE.eu :: List Of Users With Roles In ASP.NET MVC Identity

clock July 13, 2018 11:21 by author Peter

In this article, we will learn how to list all users with Associated Roles in ASP.NET MVC 5 using Identity. ASP.NET MVC 5 does not come with an inbuilt feature to list users with associated roles by default. However ASP.NET MVC have inbuilt UserManager, SignManager and RoleManager to assist this.

We need this feature in each of our applications as users are to be maintained along with their associated roles. We can apply a number of ideas to do this. In this article, we will learn a very simple way to list users with their associated RoleName as in the figure below.

Step 1
Create a View Model as Users-in-Role_ViewModel
public class Users_in_Role_ViewModel 
    { 
        public string UserId { get; set; } 
        public string Username { get; set; } 
        public string Email { get; set; } 
        public string Role { get; set; } 
    } 


Step 2
Add a new method called UsersWithRoles inside ManageUsersController and add the following codes.
public ActionResult UsersWithRoles() 
        { 
            var usersWithRoles = (from user in context.Users 
                                  select new 
                                  { 
                                      UserId = user.Id,                                       
                                      Username = user.UserName, 
                                      Email = user.Email, 
                                      RoleNames = (from userRole in user.Roles 
                                                   join role in context.Roles on userRole.RoleId  
                                                   equals role.Id 
                                                   select role.Name).ToList() 
                                  }).ToList().Select(p => new Users_in_Role_ViewModel() 
  
                                  { 
                                      UserId = p.UserId, 
                                      Username = p.Username, 
                                      Email = p.Email, 
                                      Role = string.Join(",", p.RoleNames) 
                                  }); 
  
  
            return View(usersWithRoles); 
        } 


Note - context.Users represents the table AspNetUsers which has navigation property roles which represent the AspNetUserInRoles table.

Step 3
Now, let’s add a View of UsersWithRoles method of ManageUsersController.
@model IEnumerable<MVC5Demo.UI.ViewModels.Users_in_Role_ViewModel> 
@{ 
    ViewBag.Title = "Users With Roles"; 
    Layout = "~/Views/Shared/_Layout.cshtml"; 

  
<div class="panel panel-primary"> 
    <div class="panel-heading"> 
        <h3 class="box-title"> 
            <b>Users with Roles</b> 
        </h3> 
    </div> 
    <!-- /.box-header --> 
    <div class="panel-body"> 
        <table class="table table-hover table-bordered table-condensed" id="UsersWithRoles"> 
            <thead> 
                <tr> 
                    <td><b>Username</b></td> 
                    <td><b>Email</b></td> 
                    <td><b>Roles</b></td> 
                </tr> 
            </thead> 
            @foreach (var user in Model) 
            { 
                <tr> 
                    <td>@user.Username</td> 
                    <td>@user.Email</td> 
                    <td>@user.Role</td> 
                     
                </tr> 
            } 
        </table> 
    </div> 
  
    <div class="panel-footer"> 
        <p class="box-title"><b>Total Users till @String.Format("{0 : dddd, MMMM d, yyyy}", DateTime.Now)  : </b><span class="label label-primary">@Model.Count()</span></p> 
    </div> 
</div> 
  
  
@section scripts{ 
    <script> 
        $(function () { 
            $('#UsersWithRoles').DataTable({ 
                "paging": true, 
                "lengthChange": true, 
                "searching": true, 
                "ordering": true, 
                "info": true, 
                "autoWidth": true 
            }); 
        }); 
    </script> 


Now, the above method and View will return the users to their roles.

n



ASP.NET MVC Hosting - HostForLIFE.eu :: Using Ajax in MVC Application

clock June 21, 2016 00:16 by author Anthony

In asp.net web form application, if we need ajax service, we will need to create wcf services on server side to serve ajax calls, while in MVC web application, no wcf is needed, a controller will do.

Here are two examples (GET and POST) of how to use ajax in mvc application

Http Get example: ajax consumer in view

<script type="text/javascript">
  var user = {
                'id': 1
            };
    $.get(
                'home/getUser',
                user,
                function (data) {
                    alert(data.name);
                }
    );
</script>


Http Get example: ajax server in home controller

public class HomeController : Controller
{
    // data GET service
     public JsonResult getUser(int id)
     {
            User user = db.Users.where(u=>u.id==id)
            return Json(user,JsonRequestBehavior.AllowGet);     }
}

A few points:


Controller must return JsonResult rather than ActionResult as a normal controller does as we would want the data to be returnd as json data, and it does not have a ‘d’ wrapper

JsonRequestBehavior.AllowGet must be set in Json()call, otherwise you will get:

500 internal server error with message like

This request has been blocked because sensitive information could be disclosed to third party web sites when this is used in a GET request. To allow GET requests, set JsonRequestBehavior to AllowGet

You only need to set this parameter for GET and returning JSON array to avoid JSON hijacking, no need for POST requests.
Http POST example: ajax consumer in view


<script type="text/javascript">
var user={
            'name':’TheUser’,
            'age':30
        };
 $.post(
            'home/SaveUser',
            user,
            function (data) {
                if (data === true) {
                   alert('User is saved');
                }
                else {

                    alert('Failed to save the user');
                }
            },
            'json'
        );
</script>


Http POST example: ajax server in home controller

public class HomeController : Controller
{
    // data POST service
  [AcceptVerbs(HttpVerbs.Post)]
   public JsonResult SaveUser (string name, int age)
   {
        return Json(true);    }
}

A few points:

Have to decorate the controller with ‘POST’

Datatype in $.post in example is set to json, but it is not necessary to be so, if you just pass data in fields rather than in complex object. When it is not set to json it will use application/x-www-form-urlencoded as a way to pass data in standard post.


Summary:
In asp.net MVC you can use controller as ajax server without having to use wcf, compared with wcf, no configuration is needed

 

HostForLIFE.eu ASP.NET MVC Hosting
HostForLIFE.eu is European Windows Hosting Provider which focuses on Windows Platform only. We deliver on-demand hosting solutions including Shared hosting, Reseller Hosting, Cloud Hosting, Dedicated Servers, and IT as a Service for companies of all sizes. We have customers from around the globe, spread across every continent. We serve the hosting needs of the business and professional, government and nonprofit, entertainment and personal use market segments.



ASP.NET MVC Hosting - HostForLIFE.eu :: Configuring ELMAH In ASP.NET MVC

clock June 13, 2016 21:35 by author Anthony

In this article, I will integrate and setup ELMAH to asp.net MVC project. I will finish whole article in 5 different steps. ELMAH stands for Error Logging Modules and Handlers providing application wide error logging facilities. ELMAH is pluggable and easy to implement without changing single line of code. ELMAH work as interceptor of unhandled dotnet exceptions, that display over yellow screen of death. As per Author you can dynamically add ELMAH on running asp.net application without recompile or re-deploy whole application.You can download ELMAH binaries from google code or if you are using nuget then visit ELMAH nuget page.

Install

The best way to install any module to Asp.net MVC project is to use Nuget package Console. You can visit ELMAH nuget page for get latest version command.

Configure

After installing ELMAH , it will automatically update Web.Config file. If it's not so you can add following code to Web.Config file.

<configuration>
<configSections>
    <sectionGroup name="elmah">
      <section name="security" requirePermission="false" type="Elmah.SecuritySectionHandler, Elmah" />
      <section name="errorLog" requirePermission="false" type="Elmah.ErrorLogSectionHandler, Elmah" />
      <section name="errorMail" requirePermission="false" type="Elmah.ErrorMailSectionHandler, Elmah" />
      <section name="errorFilter" requirePermission="false" type="Elmah.ErrorFilterSectionHandler, Elmah" />
    </sectionGroup>
</configSections>

<system.web>   
    <httpModules>
      <add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah" />
      <add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah" />
      <add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah" />
    </httpModules>
</system.web>

<system.webServer>
<modules>
      <add name="ErrorLog" type="Elmah.ErrorLogModule, Elmah" preCondition="managedHandler" />
      <add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah" preCondition="managedHandler" />
      <add name="ErrorFilter" type="Elmah.ErrorFilterModule, Elmah" preCondition="managedHandler" />
</modules>
</system.webServer>
<elmah>
    <security allowRemoteAccess="false" />
    <errorLog type="Elmah.SqlErrorLog, Elmah" connectionStringName="YourConnectionStringName" />
</elmah>
    <location path="elmah.axd" inheritInChildApplications="false">
    <system.web>
      <httpHandlers>
        <add verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah" />
      </httpHandlers>
      <!--
      <authorization>
        <allow roles="admin" />
        <deny users="*" /> 
      </authorization>
      --> 
    </system.web>
    <system.webServer>
      <handlers>
        <add name="ELMAH" verb="POST,GET,HEAD" path="elmah.axd" type="Elmah.ErrorLogPageFactory, Elmah" preCondition="integratedMode" />
      </handlers>
    </system.webServer>
  </location>
</configuration>
Usage Now, It's time to use and test elmah for application. Generate exception in Home Controller
public ActionResult Index()
{
   throw new Exception("This is test Exception");
          
   return View();
}


after generating exception check your elmah like http://www.example.com/elmah.axd
Here is our output

integrate-elmah-in-aspnet-mvc

integrate elmah in asp. net mvc

Security

In addition ELMAH provides seamless security feature to prevent unauthorized access. Please read our next article to make your elmah secure.

Filtering

ELMAH identify and store exceptions in different category, you can make or edit ELMAH error screen with different filters which we will discuss in our next ELMAH series.

Notification

You can setup ELMAH email notification when any exception occurs. To unable notification option you must include below code

Add ErrorMail module
<httpModules>
    <add name="ErrorMail" type="Elmah.ErrorMailModule, Elmah"/>
</httpModules>


Add SMTP Setting
<system.net>
    <mailSettings>
        <smtp deliveryMethod="network">
            <network host="..." port="25" userName="..." password="..." />
        </smtp>
    </mailSettings>
</system.net>
 

or
<elmah>
<errorMail from="..." to="..."  async="true" smtpServer="..." smtpPort="25" userName="..." password="..." />
</elmah>

 

 


HostForLIFE.eu ASP.NET MVC Hosting
HostForLIFE.eu is European Windows Hosting Provider which focuses on Windows Platform only. We deliver on-demand hosting solutions including Shared hosting, Reseller Hosting, Cloud Hosting, Dedicated Servers, and IT as a Service for companies of all sizes. We have customers from around the globe, spread across every continent. We serve the hosting needs of the business and professional, government and nonprofit, entertainment and personal use market segments.

 



ASP.NET MVC 5 Hosting - HostForLIFE.eu :: AngularJS Login Page in ASP.NET MVC 5

clock May 17, 2016 23:45 by author Anthony

In this tutorial i am going to explain about how to create a login page using Angular js in MVC 5 application. In this tutorial i used Simple form validation using angular(we will discuss about angular validation in detail in future post).And also a $http angular built in service.

$http: It is a angular JS built in service for communicating with remote servers.In Angular all communications (Request and response) between server and client are handled by services like $http.

Step 1: Create a Data table in Database

1.Here i used Local Database for Table creation (Sql Express).
2.Right click server explorer --> expand Database --> Right click on tables --> Click Add new table.
3.Create a table with  following columns if you want you can add more columns.
4.Here i created following table.

Step 2: Add ADO.NET Entity Data Model

1.Right click on Models --> Add --> New Item -->Select ADO.NET Entity Data Model(Under Data) --> name it -->Add --> select Add from Database (In Entity Data Model wizard) --> Next
2.Select Database --> give name for web.config.
3.Choose your Database objects(tables) and click finish.


Step 3: Add a Model Class to Solution

1.Right click Models --> Add --> Class and name it (I named it as UserModel.cs).
2.These Model objects are useful while we sending data from View to Controller.
3.We bind this Model properties with angular ngModel.(you will see in index.cshtml).
4.replace code with following code

namespace LoginUsingAngular.Models
{
    public class UserModel
    {
        public string Email { get; set; }
        public string Password { get; set; }
    }
}

Step 4: Add New Action Method in HomeController to Check User Data

1.This Action Method gets data from database based on user entered data in form.and returns that data in Json format to angular Controller.
2.Add code in HomeController
getLoginData():

public ActionResult getLoginData(UserModel obj)
        {
            DatabaseEntities db = new DatabaseEntities();
            var user = db.Users.Where(x => x.Email.Equals(obj.Email) && x.Password.Equals(obj.Password)).FirstOrDefault();
            return new JsonResult {Data=user,JsonRequestBehavior=JsonRequestBehavior.AllowGet };
        }

Step 5: Add angular controller for checking Login Form

1.Create angular module in  Module.js file.
(function () {
    var myApp = angular.module("myApp",[]);
})();

2.Now add another script file for angular controller and Factory method.
3.Right click on Scripts folder --> add LoginController.js
4.Replace code in LoginController.js file.

angular.module('myApp').controller('LoginController', function ($scope, LoginService) {
 
        //initilize user data object
        $scope.LoginData = {
            Email: '',
            Password:''
        }
        $scope.msg = "";
        $scope.Submited = false;
        $scope.IsLoggedIn = false;
        $scope.IsFormValid = false;
 
        //Check whether the form is valid or not using $watch
        $scope.$watch("myForm.$valid", function (TrueOrFalse) {
            $scope.IsFormValid = TrueOrFalse;   //returns true if form valid
        });
 
        $scope.LoginForm = function () {
            $scope.Submited = true;
            if ($scope.IsFormValid) {
                LoginService.getUserDetails($scope.UserModel).then(function (d) {
                    debugger;
                    if (d.data.Email != null) {
                        debugger;
                        $scope.IsLoggedIn = true;
                        $scope.msg = "You successfully Loggedin Mr/Ms " +d.data.FullName;
                    }
                    else {
                        alert("Invalid credentials buddy! try again");
                    }
                });
            }
        }
    })
    .factory("LoginService", function ($http) {
        //initilize factory object.
        var fact = {};
        fact.getUserDetails = function (d) {
            debugger;
            return $http({
                url: '/Home/getLoginData',
                method: 'POST',
                data:JSON.stringify(d),
                headers: { 'content-type': 'application/json' }
            });
        };
        return fact;
    });


4.Here,I validated form using $watch in above code.
5.I created a angular service LoginService that gets data from server controller (from HomeController.getLoginData() action).
6.LoginForm() method is initiated when user submits form using ngSubmit as angular attribute.


Step 6: Add View to display Login Form

1.Right click on Index action --> Add View --> add
2.Replace Index.cshtml view code with following code

@{
    ViewBag.Title = "Login Using Angular";
}
<h2>Login Using Angular</h2>

<div ng-controller="LoginController">
    <form name="myForm" novalidate ng-submit="LoginForm()">
        <div style="color:green">{{msg}}</div>
        <table ng-show="!IsLoggedIn" class="table table-horizontal">
            <tr>
                <td>Email/UserName :</td>
                <td>
                    <input type="email" ng-model="UserModel.Email" name="UserEmail" ng-class="Submited?'ng-dirty':''" required autofocus class="form-control"/>
                    <span style="color:red" ng-show="(myForm.UserEmail.$dirty || Submited ) && myForm.UserEmail.$error.required">Please enter Email</span>
                    <span style="color:red" ng-show="myForm.UserEmail.$error.email">Email is not valid</span>
                </td>
            </tr>
            <tr>
                <td>Password :</td>
                <td>
                    <input type="password" ng-model="UserModel.Password" name="UserPassword" ng-class="Submited?'ng-dirty':''" required autofocus class="form-control"/>
                    <span style="color:red" ng-show="(myForm.UserPassword.$dirty || Submited) && myForm.UserPassword.$error.required">Password Required</span>
                </td>
            </tr>
            <tr>
                <td></td>
                <td>
                    <input type="submit" value="submit" class="btn btn-success" />
                </td>
            </tr>
        </table>
    </form>
</div>
@section scripts{
    <script src="~/Scripts/LoginController.js"></script>
}

Add script reference at the end of Index.cshtml page.
Take a look at following things i used in above Index.cshtml view.

ng-Model: ngModel is a angular directive.it is used for two way binding data from view to controller and controller to view.In above example i used it to bind from data to angular controller.

ng-show: ngShow allows to display or hide elements based on the expression provided to ngShow attribute.

ng-submit:  ng-submit prevents the default action of form and binds angular function to onsubmit events. This is invoked when form is submitted.

$dirty: It is angular built in property. It will be true if user interacted with form other wise false.This is one of the angular validation property i used in above example.There are many validation properties in angular like $invalid,$submitted,$pristine,$valid and $error.We will learn about all these these properties in later tutorials.

 




ASP.NET MVC 5 Hosting - HostForLIFE.eu :: How To Create Area?

clock April 28, 2016 20:59 by author Anthony

Today, you will learn how to create Area in MVC 5. In MVC 5 (Visual Studio 2013), Area option can be found under ‘Add Scaffold’ dialog. In this post, I will take you through step by step to setup and running Area in MVC 5.


As you know MVC Architecture separates all the logics: model logic, business logic and presentation logic and provides a very clean and light weight application in total. One more good thing that I love is, it provides logical separation physically also. In physical logic separation controllers, models and views are kept in another folder on root with the help of Area. Areas provide a way to separate a large MVC Web Application into smaller functional groupings inside MVC Application and each group contains MVC Structure (Ex. Model, View and Controller folders). Area was introduced with MVC 2 release.

Assume, you are working on a MVC Project where you have a requirement  to develop various sections like account section, administrative section, support section, billing section and so on. Area is the best choice here, it will provide a strong physical structure as well as better code manageability. See how it looks like.

 


You can see every section has MVC Architecture Controller, Model, View (view will have a Shared folder where you can place your layouts, partial views etc) and an AreaRegistration (which contains RegisterArea method very similar to RegisterRoutes).

How to Create It

We are going to create CRUD views for Employee inside Area. We will take the advantage of EF Code First. Let’s walk through the simple steps. In Visual Studio 2012 IDE (MVC 4), we just right click on Project | Add | Area to create Area.

 

Step 1


Right click on Project and then select Add | Scaffold | MVC 5 Area.

Step 2

When we click on ‘Scaffold’ it opens a dialog where we need to select MVC 5 Area and hit on Add button, it will ask to enter area name, type ‘Admin’ and hit Add.
Do the same to add Area for Billing and Support, at the end we will have following structure.



 

Now once we are done with adding areas, go to next step.

Step 3


In above step we added three Areas, in each area we will find a class file areanameAreaRegistration.cs file, open this file, we will find following RegisterArea method inside class which inherits AreaRegistration class.

public override void RegisterArea(AreaRegistrationContext context)
{
    context.MapRoute(
        "Billing_default",
        "Admin/{controller}/{action}/{id}",
        new { action = "Index", id = UrlParameter.Optional }
    );
}


Look at this root closely, we will find this route begins with Admin and then controller, action and id (which is marked as optional).


We will find same thing in other Area also.

In total we have three areanameAreaRegistration.cs classes all inherits AreaRegistration class, and also a route defined for the Area. These routes should be registered inside Application_Start() method of Global.asax file, here is the code.

protected void Application_Start()
{
    AreaRegistration.RegisterAllAreas();

    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    RouteConfig.RegisterRoutes(RouteTable.Routes);
    BundleConfig.RegisterBundles(BundleTable.Bundles);
}


Now, let’s go in next step where we will create CRUD views and see how it opens in browser.


Step 4


Once we have done with previous steps, just go ahead and add model, controller and views to see how area opens in browser. We could and anything we want but just to keep things simple I am going to create a CRUD in Admin Area for Employee, here is the model I will be using.

public class Employee
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Address { get; set; }
}

Now, create CRUD views and browse it.

Look at the URL in above image you will see the first segment ‘Admin’ is area name, second segment ‘Employee’ is controller, third segment ‘Details’ is action result and fourth segment ‘1’ is ID.


So, you can see how Area is working in MVC 5. There is no difference in ‘Area in MVC 4’ and ‘Area in MVC 5’, things are still same, the only change is the way Area added, that’s it.

 

HostForLIFE.eu ASP.NET MVC 5 Hosting
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offer a highly redundant, carrier-class architecture, designed around the needs of shared hosting customers.

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ASP.NET MVC 5 Hosting - HostForLIFE.eu :: How to Handle ASP.NET MVC 5 Errors?

clock April 27, 2016 23:38 by author Anthony

Custom error pages and global error logging are two elementary and yet very confusing topics in ASP.NET MVC 5.

There are numerous ways of implementing error pages in ASP.NET MVC 5 and when you search for advice you will find a dozen different StackOverflow threads, each suggesting a different implementation.

Overview

What is the goal?


Typically good error handling consists of:

  • Human friendly error pages
    • Custom error page per error code (e.g.: 404, 403, 500, etc.)
    • Preserving the HTTP error code in the response to avoid search engine indexing
  • Global error logging for unhandled exceptions

Error pages and logging in ASP.NET MVC 5


There are many ways of implementing error handling in ASP.NET MVC 5. Usually you will find solutions which involve at least one or a combination of these methods:

  • HandleErrorAttribute
  • Controller.OnException Method
  • Application_Error event
  • CustomErrors element in web.config
  • httpErrors element in web.config
  • Custom HttpModule

All these methods have a historical reason and a justifyable use case. There is no golden solution which works for every application. It is good to know the differences in order to better understand which one is applied best.

Before going through each method in more detail I would like to explain some basic fundamentals which will hopefully help in understanding the topic a lot easier.

ASP.NET MVC Fundamentals


The MVC framework is only a HttpHandler plugged into the ASP.NET pipeline. The easiest way to illustrate this is by opening the Global.asax.cs:

public class MvcApplication : System.Web.HttpApplication
Navigating to the implementation of HttpApplication will reveal the underlying IHttpHandler and IHttpAsyncHandler interfaces:

public class HttpApplication : IComponent, IDisposable, IHttpAsyncHandler, IHttpHandler
ASP.NET itself is a larger framework to process incoming requests. Even though it could handle incoming requests from different sources, it is almost exclusively used with IIS. It can be extended with HttpModules and HttpHandlers.

HttpModules are plugged into the pipeline to process a request at any point of the ASP.NET life cycle. A HttpHandler is responsible for producing a response/output for a request.

IIS (Microsoft's web server technology) will create an incoming request for ASP.NET, which subsequently will start processing the request and eventually initialize the HttpApplication (which is the default handler) and create a response:

IIS, ASP.NET and MVC architecture

The key thing to know is that ASP.NET can only handle requests which IIS forwards to it. This is determined by the registered HttpHandlers (e.g. by default a request to a .htm file is not handled by ASP.NET).

And finally, MVC is only one of potentially many registered handlers in the ASP.NET pipeline.

This is crucial to understand the impact of different error handling methods.

Breaking down the options


HandleErrorAttribute

The HandleErrorAttribute is an MVC FilterAttribute, which can be applied to a class or a method:

namespace System.Web.Mvc
{
    [AttributeUsage(
        AttributeTargets.Class | AttributeTargets.Method,
        Inherited = true,
        AllowMultiple = true)]
    public class HandleErrorAttribute : FilterAttribute, IExceptionFilter
    {
        // ...
    }
}

It's error handling scope is limited to action methods within the MVC framework. This means it won't be able to catch and process exceptions raised from outside the ASP.NET MVC handler (e.g. exceptions at an earlier stage in the life cycle or errors in other handlers). It will equally not catch an exception if the action method is not part of the call stack (e.g. routing errors).

Additionally the HandleErrorAttribute only handles 500 internal server errors. For instance this will not be caught by the attribute:

[HandleError]
public ActionResult Index()
{
    throw new HttpException(404, "Not found");
}

You can use the attribute to decorate a controller class or a particular action method. It supports custom error pages per exception type out of the box:

[HandleError(ExceptionType = typeof(SqlException), View = "DatabaseError")]]
In order to get the HandleErrorAttribute working you also need to turn customErrors mode on in your web.config:

<system.web>
    <customErrors mode="On" />
</system.web>

Use case

The HandleErrorAttribute is the most limited in scope. Many application errors will bypass this filter and therefore it is not ideal for global application error handling.

It is a great tool for action specific error handling like additional fault tolerance for a critical action method though.

Controller.OnException Method


The OnException method gets invoked if an action method from the controller throws an exception. Unlike the HandleErrorAttribute it will also catch 404 and other HTTP error codes and it doesn't require customErrors to be turned on.

It is implemented by overriding the OnException method in a controller:

protected override void OnException(ExceptionContext filterContext)
{
    filterContext.ExceptionHandled = true;
           
    // Redirect on error:
    filterContext.Result = RedirectToAction("Index", "Error");

    // OR set the result without redirection:
    filterContext.Result = new ViewResult
    {
        ViewName = "~/Views/Error/Index.cshtml"
    };
}

With the filterContext.ExceptionHandled property you can check if an exception has been handled at an earlier stage (e.g. the HandleErrorAttribute):

if (filterContext.ExceptionHandled)
    return;

Many solutions on the internet suggest to create a base controller class and implement the OnException method in one place to get a global error handler.

However, this is not ideal because the OnException method is almost as limited as the HandleErrorAttribute in its scope. You will end up duplicating your work in at least one other place.

Use case


The Controller.OnException method gives you a little bit more flexibility than the HandleErrorAttribute, but it is still tied to the MVC framework. It is useful when you need to distinguish your error handling between regular and AJAX requests on a controller level.

Application_Error event


The Application_Error method is far more generic than the previous two options. It is not limited to the MVC scope any longer and needs to be implemented in the Global.asax.cs file:

protected void Application_Error(Object sender, EventArgs e)
{
    var raisedException = Server.GetLastError();

    // Process exception
}

If you've noticed it doesn't come from an interface, an abstract class or an overriden method. It is purely convention based, similar like the Page_Load event in ASP.NET Web Forms applications.

Any unhandeled exception within ASP.NET will bubble up to this event. There is also no concept of routes anymore (because it is outside the MVC scope). If you want to redirect to a specific error page you have to know the exact URL or configure it to co-exist with "customErrors" or "httpErrors" in the web.config.

Use case


In terms of global error logging this is a great place to start with! It will capture all exceptions which haven't been handled at an earlier stage. But be careful, if you have set filterContext.ExceptionHandled = true in one of the previous methods then the exception will not bubble up to Application_Error.

However, for custom error pages it is still not perfect. This event will trigger for all ASP.NET errors, but what if someone navigates to a URL which isn't handled by ASP.NET? For example try navigating to http://{your-website}/a/b/c/d/e/f/g. The route is not mapped to ASP.NET and therefore the Application_Error event will not be raised.

customErrors in web.config


The "customErrors" setting in the web.config allows to define custom error pages, as well as a catch-all error page for specific HTTP error codes:

<system.web>
    <customErrors mode="On" defaultRedirect="~/Error/Index">
        <error statusCode="404" redirect="~/Error/NotFound"/>
        <error statusCode="403" redirect="~/Error/BadRequest"/>
    </customErrors>
<system.web/>

By default "customErrors" will redirect a user to the defined error page with a HTTP 302 Redirect response. This is really bad practise because the browser will not receive the appropriate HTTP error code and redirect the user to the error page as if it was a legitimate page. The URL in the browser will change and the 302 HTTP code will be followed by a 200 OK, as if there was no error. This is not only confusing but has also other negative side effects like Google will start indexing those error pages.

You can change this behaviour by setting the redirectMode to "ResponseRewrite":

<customErrors mode="On" redirectMode="ResponseRewrite">

This fixes the initial problem, but will give a runtime error when redirecting to an error page now:

Runtime Error

An exception occurred while processing your request. Additionally, another exception occurred while executing the custom error page for the first exception. The request has been terminated.
This happens because "ResponseRewrite" mode uses Server.Transfer under the covers, which looks for a file on the file system. As a result you need to change the redirect path to a static file, for example to an .aspx or .html file:

<customErrors mode="On" redirectMode="ResponseRewrite" defaultRedirect="~/Error.aspx"/>
Now there is only one issue remaining with this configuration. The HTTP response code for the error page is still "200 OK". The only way to fix this is to manually set the correct error code in the .aspx error page:

<% Response.StatusCode = 404; %>
This is already pretty good in terms of custom error pages, but we can do better!

Noticed how the customErrors section goes into the system.web section? This means we are still in the scope of ASP.NET.

Files and routes which are not handled by your ASP.NET application will render a default 404 page from IIS (e.g. try http://{your-website}/not/existing/image.gif).

Another downside of customErrors is that if you use a HttpStatusCodeResult instead of throwing an actual exception then it will bypass the ASP.NET customErrors mode and go straight to IIS again:

public ActionResult Index()
{
    return HttpNotFound();
    //throw new HttpException(404, "Not found");
}

In this case there is no hack which can be applied to display a friendly error page which comes from customErrors.

Use case


The customErrors setting was for a long time the best solution, but still had its limits. You can think of it as a legacy version of httpErrors, which has been only introduced with IIS 7.0.

The only time when customErrors still makes sense is if you can't use httpErrors, because you are running on IIS 6.0 or lower.

httpErrors in web.config

The httpErrors section is similar to customErrors, but with the main difference that it is an IIS level setting rather than an ASP.NET setting and therefore needs to go into the system.webserver section in the web.config:

<system.webServer>
    <httpErrors errorMode="Custom" existingResponse="Replace">
      <clear/>
      <error
        statusCode="404"
        path="/WebForms/Index.aspx"
        responseMode="ExecuteURL"/>
    </httpErrors>
<system.webServer/>

It allows more configuration than customErrors but has its own little caveats. I'll try to explain the most important settings in a nutshell:

httpErrors can be inherited from a higher level (e.g. set in the machine.config)
Use the <remove/> tag to remove an inherited setting for a specific error code.
Use the <clear/> tag to remove all inherited settings.
Use the <error/> tag to configure the behaviour for one error code.
responseMode "ExecuteURL" will render a dynamic page with status code 200.
The workaround to set the correct error code in the .aspx page works here as well.
responseMode "Redirect" will redirect with HTTP 302 to a URL.
responseMode "File" will preserve the original error code and output a static file.
.aspx files will get output in plain text.
.html files will render as expected.
The main advantage of httpErrors is that it is handled on an IIS level. It will literally pick up all error codes and redirect to a friendly error page. If you want to benefit from master pages I would recommend to go with the ExecuteURL approach and status code fix. If you want to have rock solid error pages which IIS can serve even when everything else burns, then I'd recommend to go with the static file approach (preferably .html files).

Use case


This is currently the best place to configure friendly error pages in one location and to catch them all. The only reason not to use httpErrors is if you are still running on an older version of IIS (< 7.0).

Custom HttpModule


Last but not least I would like to quickly touch on custom HttpModules in ASP.NET. A custom HttpModule is not very useful for friendly error pages, but it is a great location to put global error logging in one place.

With a HttpModule you can subscribe to the OnError event of the HttpApplication object and this event behaves same way as the Application_Error event from the Global.asax.cs file. However, if you have both implemented then the one from the HttpModule gets called first.

The benefit of the HttpModule is that it is reusable in other ASP.NET applications. Adding/Removing a HttpModule is as simple as adding or removing one line in your web.config:

<system.webServer>
    <modules>
        <add name="CustomModule" type="SampleApp.CustomModule, SampleApp"/>
    </modules>
</system.webSe
rver>

 

 


HostForLIFE.eu ASP.NET MVC 5 Hosting
HostForLIFE.eu revolutionized hosting with Plesk Control Panel, a Web-based interface that provides customers with 24x7 access to their server and site configuration tools. Plesk completes requests in seconds. It is included free with each hosting account. Renowned for its comprehensive functionality - beyond other hosting control panels - and ease of use, Plesk Control Panel is available only to HostForLIFE's customers. They
offer a highly redundant, carrier-class architecture, designed around the needs of shared hosting customers.

 



About HostForLIFE.eu

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