Read B2C Token from Razor MVC Application

 To Retrieve B2C logged in users token for delegate permissions, follow below steps,

Add below lines in startup,

// Configuration to sign-in users with Azure AD B2C

   services.AddMicrosoftIdentityWebAppAuthentication(Configuration, Constants.AzureAdB2C).

        EnableTokenAcquisitionToCallDownstreamApi(new string[] { "https://graph.microsoft.com/.default" })

       .AddInMemoryTokenCaches();

services.Configure<OpenIdConnectOptions>(OpenIdConnectDefaults.AuthenticationScheme, options =>

{

    options.TokenValidationParameters = new TokenValidationParameters

    {

        ValidAudience = "https://graph.microsoft.com"

    };

    options.SaveTokens = true;

});

 

services.Configure<ConfidentialClientApplicationOptions>(options =>

{

    options.ClientSecret = Configuration["AzureAdB2C:ClientSecret"];

});

 

services.ConfigureApplicationCookie(options =>

{

    options.Cookie.SameSite = SameSiteMode.None;

    options.Cookie.SecurePolicy = CookieSecurePolicy.Always;

});

 

Now retrieve token from Controller with below syntax,

    HttpContext.GetTokenAsync("access_token").Result

    or

    HttpContext.GetTokenAsync("id_token").Result

   

C# - How to merge paths with slashes in all subsequent params

To combine file paths with slashes will take care by below code

public static string MergePath(params string[] stringPaths)

        {

            for (int i = 0; i < stringPaths.Length; i++)

            {

                //To skip trim on first path

                if (i != 0)

                    stringPaths[i] = stringPaths[i].Trim().TrimStart(Path.DirectorySeparatorChar).TrimEnd(Path.DirectorySeparatorChar);

            }

            return Path.Combine(stringPaths);

        }

Example:

var stringtest = Extensions.MergePath(@"c:\path\", @"\dir\file.txt");

var stringtest2 = Extensions.MergePath(@"c:\path\",@"\test\adsf\", @"\dir\file.txt");

var stringtest3 = Extensions.MergePath(@"c:\path", @"test\adsf", @"dir\file.txt");

Output:

"c:\\path\\dir\\file.txt"

"c:\\path\\test\\adsf\\dir\\file.txt"

"c:\\path\\test\\adsf\\dir\\file.txt"

MVC - Domain Route for Multi tenancy application to handle different URL

In some cases, we should handle Multi-tenant application with single code base and different domain URLs.

So how do we handle that in MVC Routing?

We have got "Constraints" concept in MVC routing, this is very helpful to filter URL based on domain also.

Okay, let us consider we have different URLs for same code base  for ex:  CompanyAName.com, CompanyBName.com. So here we have to handle two different domain URLs considering URLs already configured for same application.

routes.MapRoute(

    name: "CompanyARoute",

    url: "{controller}/{action}/{id}",

    defaults: new { controller = "Index", action = "Home", id = UrlParameter.Optional },

    constraints: new { host = "CompanyAName.com" });

routes.MapRoute(

    name: "CompanyBRoute",

    url: "{controller}/{action}/{id}",

    defaults: new { controller = "Index", action = "Home", id = UrlParameter.Optional },

    constraints: new { host = "CompanyBName.com" });

This code will handle two different domains, "host" in constraints is default syntax and will map to domain automatically. here we can change default Controller, Action to anything or even we can pass some parameters. 

Suppose, if we want to add some subdomain as companyname. For ex;   DefaultURL.com/CompanyName

We can use same "Constraints" to handle this

  routes.MapRoute(

    name: "SubRoute",

    url: "{companyName}/{controller}/{action}/{id}",

    defaults: new { controller = "Index", action = "Home", id = UrlParameter.Optional },

    constraints: new { companyName = "CompanyA" });

To handle multiple company names we can create more routing same like this or even in companyName we can add more like "(CompanyA|CompanyB)". "companyName" in constraints mapped to {companyName} in url.

We can utilize IRouteConstraint interface to extend each constraints attributes.

routes.MapRoute(

  name: "ConstraintRoute,

  url: "{controller}/{action}/{id}",

  defaults: new { controller = "Index", action = "Home", id = UrlParameter.Optional },

  constraints: new { host = new HostRouteConstraint("CompanyAName.com") });

"HostRouteConstraint" is a class extended from IRouteConstraint

using System.Web.Routing;

public class HostRouteConstraint : IRouteConstraint

    {

        private readonly string _host;

        public DomainConstraint(string host)

        {

            _host = host.ToLower();

        }

        public bool Match(HttpContextBase httpContext,

            System.Web.Routing.Route route,

            string parameterName,

            RouteValueDictionary values,

            RouteDirection routeDirection)

        {

//Here you can do your custom logic to match host

            return httpContext.Request.Url.AbsoluteUri.ToLower().Contains(_host);

        }

    }

MVC - Cache dynamic files in browser based on query string from action results

To cache we can do many things such as StaticCache in webconfig, HTML5 manifest cache and also we can use OutputCache in MVC.

To enable cache for dynamically changing contents. For ex, to load images based on file name and to cache use following attribute in controller or action.

        [HttpGet]

        [OutputCache(Duration = 600, VaryByParam = "imageFileName")]

        public FileResult GetSomeImageFile(string imageFileName)

        {

//your logic to load image file

 }

Here Duration mentioned in seconds and VaryByParam property to specify to cache based on parameter name 'imageFileName'

MVC & WebAPI - Model Binder

There are some specific cases in order to use model binder to MVC and WebAPI in same project.

Here i will explain step by step to implement MVC and WebAPI Model Binders

What is Model Binder?

In some cases, we should do common operations for all actions inside controller. So in that case we can add model binder and pass as parameter to actions. In below example UserModel class sent as Model Binder

public ActionResult Index([ModelBinder]UserModel model)

{

...

}

Implementing Model Binder for MVC

MVC uses different namespace such as System.Web.Mvc. So Model Binder class also should use the same.

Step 1:

Create UserModel class as required. Here we can add our required properties. In this example, i am going to display UserId and UserName

public class UserModel

    {

        public string UserId { get; set; }

        public string UserName { get; set; }

    }

Step 2:

Create custom ModelBinder class which can be implemented from System.Web.Mvc.IModelBinder as below. Here i created as partial for merging with WebAPI. If you dont need WebAPI then just have it as normal class

public partial class UserModelBinder : System.Web.Mvc.IModelBinder

    {

        public object BindModel(System.Web.Mvc.ControllerContext controllerContext, System.Web.Mvc.ModelBindingContext bindingContext)

        {

            if (bindingContext.ModelType != typeof(UserModel))

            {

                return null;

            }

            UserModel userModel = new UserModel();

            var userId = HttpContext.Current.User.Identity.GetUserId();

            if (!string.IsNullOrEmpty(userId))

            {

/// Create your custom logics to fill the other required details. In this example i can fill username

            }

            return userModel;

        }

    }

Step 3:

Register this Custom ModelBinder class into Global.asax.cs file

protected void Application_Start()

        {

            AreaRegistration.RegisterAllAreas();

            WebApiConfig.Register(GlobalConfiguration.Configuration);

            FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);

            RouteConfig.RegisterRoutes(RouteTable.Routes);

            BundleConfig.RegisterBundles(BundleTable.Bundles);

            //Model binder for MVC controller usermodel

            ModelBinders.Binders.Add(typeof(UserModel), new UserModelBinder());

        }

Step 4:

Use this custom model binder in action methods of MVC controller

public ActionResult Index([System.Web.Http.ModelBinding.ModelBinder]UserModel model)

{

...

 //Write your logic to do with UserModel class object

}

Thats all for MVC Model Binder.

Implementing Model Binder for WebAPI

WebAPI cannot be worked with MVC model binder. So we need to create differently. Step 1 to create UserModel is same. So i will go from Step 2

Step 2:

Create Custom Model Binder for WebAPI as follows. Here IModelBinder uses System.Web.Http.ModelBinding.

using Microsoft.AspNet.Identity;

using System.Web;

using System.Web.Http;

using System.Web.Http.ModelBinding;

public partial class UserModelBinder : IModelBinder

    {

        public bool BindModel(System.Web.Http.Controllers.HttpActionContext actionContext, ModelBindingContext bindingContext)

        {

            if (bindingContext.ModelType != typeof(UserModel))

            {

                return false;

            }

            UserModel userModel = new UserModel();

            var userId = HttpContext.Current.User.Identity.GetUserId();

            if (!string.IsNullOrEmpty(userId))

            {

               //Your logic to fill usermodel class and assign to binding context’s model

                bindingContext.Model = userModel;

                return true;

            }

            bindingContext.ModelState.AddModelError(bindingContext.ModelName, "Error in model binding");

            return false;

        }

    }

Step 3:

Create ModelBinderProvider class as follows. It is going to be register with configuration. Here ModelBinderProvider uses namespace System.Web.Http.ModelBinding..

public class UserModelBinderProvider : ModelBinderProvider

    {

        private System.Type type;

        private UserModelBinder userModelBinder;

        public UserModelBinderProvider(System.Type type, UserModelBinder userModelBinder)

        {

            this.type = type;

            this.userModelBinder = userModelBinder;

        }

        public override IModelBinder GetBinder(HttpConfiguration configuration, System.Type modelType)

        {

            if (modelType == type)

            {

                return userModelBinder;

            }

            return null;

        }

    }

Step 4:

Register ModelBinderProvider in Global.asax.cs file under WebApiConfig register method

public static class WebApiConfig

    {

    public static void Register(HttpConfiguration config)

        {

         var provider = new UserModelBinderProvider(typeof(UserModel), new UserModelBinder());

         config.Services.Insert(typeof(ModelBinderProvider), 0, provider);

Step 5:

Use in APIController action methods as follows

[HttpGet]

        public string GetUserName([ModelBinder]UserModel model)

        {

              return model.UserName;

  }

Thats all for WebAPI Model Binder.