Skip to main content

Part-2 Adding New User Into Database And Generating Custom JWT Token - (Blazor WebAssembly Standalone App Google Authentication)

Part-1 implemented sample to work with Google authentication into a Blazor WebAssembly standalone application. Now in this article, we will create user records into our database on users authenticated into our application using a Google account. Also, create a custom JWT for our secured endpoint. Because token given by google for our blazor web assembly application can't be used against our own secured endpoint. So while saving the user record into our database we will also generate the JWT token.

Configure Email Scope:

By default, the Blazor WebAssembly template requests scope like 'openid', 'profile'. Now we have to add one more additional scope like 'email'.

If you observe after login with a google account, the user email is not sent by google as a claim to our blazor application.

So to add user record we should have the email address, so for that let's add a new scope like 'email', which will give us user email address as one of the claims in google response token. So in 'AddOidcAuthentication' method, we have to configure the email scope.
Program.cs:
builder.Services.AddOidcAuthentication(options =>
{
	// Configure your authentication provider options here.
	// For more information, see https://aka.ms/blazor-standalone-auth
	builder.Configuration.Bind("Local", options.ProviderOptions);

	options.ProviderOptions.DefaultScopes.Add("email");
});

Create A .Net5 Web API And Configure Entity Framework Core:

So to register users into the database and creating a custom jwt token that is used to secure endpoints, so let's create a .Net5 Web API.

Install entity framework core NuGet.
Package Manager:
Install-Package Microsoft.EntityFrameworkCore -Version 5.0.5
.Net CLI:
dotnet add package Microsoft.EntityFrameworkCore --version 5.0.5
Install SQL extension for entity framework core NuGet.
Package Manager:
Install-Package Microsoft.EntityFrameworkCore.SqlServer -Version 5.0.5
.Net CLI
dotnet add package Microsoft.EntityFrameworkCore.SqlServer --version 5.0.5
Design tables like 'User' and 'UserRoles' like below.

Now we will implement database context to establish a connection with the database.
Data/Entities/User.cs:
using System;
using System.ComponentModel.DataAnnotations;

namespace BwasmAPI.GoogleAuth.Data.Entities
{
    public class User
    {
        [Key]
        public int UserId { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string EmailAddress { get; set; }
        public string Password { get; set; }
        public string RefreshToken { get; set; }
        public DateTime? RefershTokenExpiration { get; set; }
    }
}
Data/Entities/UserRoles.cs:
using System.ComponentModel.DataAnnotations;

namespace BwasmAPI.GoogleAuth.Data.Entities
{
    public class UserRoles
    {
        [Key]
        public int RoleId { get; set; }
        public int UserId { get; set; }
        public string Name { get; set; }
    }
}
Data/AuthContext.cs:
using BwasmAPI.GoogleAuth.Data.Entities;
using Microsoft.EntityFrameworkCore;

namespace BwasmAPI.GoogleAuth.Data
{
    public class AuthContext : DbContext
    {
        public AuthContext(DbContextOptions<AuthContext> options) : base(options)
        {

        }

        public DbSet<User> User { get; set; }
        public DbSet<UserRoles> UserRoles { get; set; }
    }
}
Add the connectionstring in json config file.
appsettings.Development.json:
"ConnectionStrings": {
    "AuthContext":"Your_Connection_String"
}
Now register 'AuthContext' in the 'Startup.cs'.
Startup.cs:
services.AddDbContext<AuthContext>(options =>
{
	options.UseSqlServer(Configuration.GetConnectionString("AuthContext"));
});

Create EndPoint To Register Google User And Return JWT Token As Response:

Our target is to create an endpoint to register the google user. So that we can save google authenticated users into the database. Now google token can't be used against our API application, so to make our API authenticated we will generate the JWT token. So for our register endpoint, we will return our custom JWT token as a response.


Let's configure settings for the JWT token in 'appsettings.Development.json'.
appsettings.Development.json:
"TokenSettings":{
 "Issuer":"localhost:6001",
 "Audience":"localhost:5001",
 "Key":"SomeRandomlyGeneratedStringSomeRandomlyGeneratedString"
}
  • Issuer value will be used as 'iss' claim in JWT. The value should be like the domain of the 'API' that generates jwt.
  • Audience value will be used as 'aud' claim in JWT. The value should be like the domain of the client application that consumes the API.
  • The key value should be some randomly generated string.
Create a class to map the 'TokenSettings'.
Shared/TokenSettings.cs:
public class TokenSettings
{
	public string Issuer { get; set; }
	public string Audience { get; set; }
	public string Key { get; set; }
}
Register the token settings in the 'Startup.cs'.
Startup.cs:
services.Configure<TokenSettings>(Configuration.GetSection("TokenSettings"));
Let's create models for the request and response of our API. So let's create a folder like 'Models' and then add files like 'RegisterGoogleUserModel.cs'(request model) and 'TokenResponseModel.cs'(response model).
Models/RegisterGoogleUserModel:
namespace BwasmAPI.GoogleAuth.Models
{
    public class RegisterGoogleUserModel
    {
        public string FirstName{get;set;}
        public string LastName{get;set;}
        public string Email{get;set;}
    }
}
Models/TokenResponseModel:
namespace BwasmAPI.GoogleAuth.Models
{
    public class TokenResponseModel
    {
        public string JwtToken { get; set; }
    }
}

Now let's create one class 'AccountLogic.cs' and one interface 'IAccountLogic.cs' to implement our core logic for adding the user to the database and then generating the JWT token.

So first let's create the interface with a method definition as below.
Logics/IAccountLogic.cs:
using System.Threading.Tasks;
using BwasmAPI.GoogleAuth.Models;

namespace BwasmAPI.GoogleAuth.Logics
{
    public interface IAccountLogic
    {
        Task<TokenResponseModel> RegisterGoogleUser(RegisterGoogleUserModel googleUserModel);
    }
}
Now create the 'AccountLogic.cs' and inject the required settings.
Logics/AccountLogic.cs:
using System;
using System.Collections.Generic;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Security.Claims;
using System.Text;
using System.Threading.Tasks;
using BwasmAPI.GoogleAuth.Data;
using BwasmAPI.GoogleAuth.Data.Entities;
using BwasmAPI.GoogleAuth.Models;
using BwasmAPI.GoogleAuth.Shared;
using Microsoft.Extensions.Options;
using Microsoft.IdentityModel.Tokens;

namespace BwasmAPI.GoogleAuth.Logics
{
    public class AccountLogic:IAccountLogic
    {
        private readonly AuthContext _authContext;

        private readonly TokenSettings _tokenSettings;

        public AccountLogic(AuthContext authContext,
        IOptions<TokenSettings> tokenSettings)
        {
            _authContext = authContext;
            _tokenSettings = tokenSettings.Value;
        }
    }
}
Now let's implement the logic for adding the user into the database. So let's create a private method like 'CreateNewUser'.
Logics/AccountLogic.cs:
private async Task CreateNewUser(
	RegisterGoogleUserModel googleUserModel,
	User user,
	List<UserRoles> userRoles)
{
	user = new User
	{
		EmailAddress = googleUserModel.Email,
		FirstName = googleUserModel.FirstName,
		LastName = googleUserModel.LastName,
	};
	_authContext.User.Add(user);
	await _authContext.SaveChangesAsync();

	UserRoles defaultRole = new UserRoles
	{
		Name = "admin",
		UserId = user.UserId
	};

	_authContext.UserRoles.Add(defaultRole);
	await _authContext.SaveChangesAsync();
	userRoles.Add(defaultRole);
}
  • Here we are adding our google authenticated user to the database along with the default roles.
Now let's write some code to generate the custom JWT authentication token.
Logics/AccountLogic.cs:
private string GetJWTAuthKey(List<UserRoles> roles)
{
	var securtityKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_tokenSettings.Key));

	var credentials = new SigningCredentials(securtityKey, SecurityAlgorithms.HmacSha256);

	var claims = new List<Claim>();
	if ((roles?.Count ?? 0) > 0)
	{
		foreach (var role in roles)
		{
			claims.Add(new Claim(ClaimTypes.Role, role.Name));
		}
	}

	var jwtSecurityToken = new JwtSecurityToken(
		issuer: _tokenSettings.Issuer,
		audience: _tokenSettings.Audience,
		expires: DateTime.Now.AddMinutes(30),
		signingCredentials: credentials,
		claims: claims
	);

	return new JwtSecurityTokenHandler().WriteToken(jwtSecurityToken);
}
  • Here generating the JWT with the help of token settings, user claims, digital signature, etc.
Now let's implement our main method for user registration and token generation.
Logics/AccountLogic.cs:
public async Task<TokenResponseModel> RegisterGoogleUser(RegisterGoogleUserModel googleUserModel)
{
	var user = _authContext.User.Where(_ => _.EmailAddress == googleUserModel.Email).FirstOrDefault();
	List<UserRoles> userRoles = new List<UserRoles>();
	if (user == null)
	{
		// create new user and default roles
		await CreateNewUser(googleUserModel, user, userRoles);
	}

	if (userRoles.Count == 0)
	{
		userRoles = _authContext.UserRoles.Where(_ => _.UserId == user.UserId).ToList();
	}

	return new TokenResponseModel
	{
		JwtToken = GetJWTAuthKey(userRoles)
	};
}
Register 'IAccountLogic' and 'AccountLogic' in the 'Startup.cs'
Startup.cs:
services.AddScoped<IAccountLogic,AccountLogic>();
So to set up our endpoint let's create a new controller like 'AccountController.cs'.
Controllers/AccountController.cs:
using System.Threading.Tasks;
using BwasmAPI.GoogleAuth.Logics;
using BwasmAPI.GoogleAuth.Models;
using Microsoft.AspNetCore.Mvc;

namespace BwasmAPI.GoogleAuth.Controllers
{
    [ApiController]
    [Route("[controller]")]
    public class AccountController : ControllerBase
    {
        private readonly IAccountLogic _accountLogic;
        public AccountController(IAccountLogic accountLogic)
        {
            _accountLogic = accountLogic;
        }

        [HttpPost]
        [Route("register-google-user")]
        public async Task<IActionResult> RegisterGoogleUser(RegisterGoogleUserModel googleUserModel)
        {
            var result = await _accountLogic.RegisterGoogleUser(googleUserModel);
            return Ok(result);
        }
    }
}

Enable Cors In API:

To consume API by our Blazor WebAssembly application we need to enable cors.
Startup.cs:(ConfigureServices Method)
services.AddCors(options =>
{
	options.AddPolicy(name: "corsService",
	  builder =>
	  {
		  builder.AllowAnyOrigin();
		  builder.AllowAnyHeader();
		  builder.AllowAnyMethod();
	  });
});
Startup.cs:(Configure Method)
app.UseCors("corsService");
  • Add the 'UseCors' middleware after the 'UseRouting()' middleware.

Create A Typed Client(HttpClient) To Consume Register Endpoint From Our Blazor App:

Now we have to consume the register API in our Blazor application and also need to receive the JWT token.

NOTE: If we recall in previous steps in API configure with request model(RegisterGoogleUserRequestModel.cs) and response model(TokenResponseModel.cs). So in our blazor webAssembly applications also need to have the same exact classes for invoking API. So here I'm skipping them in the blog.

So to consume API we will use the Typed Client HttpClient technique. Let's create a type client class like 'AppAuthClient.cs'.
ApiCalls/AppAuthClient.cs:
using System.Net.Http;
using System.Net.Http.Json;
using System.Text;
using System.Text.Json;
using System.Threading.Tasks;
using BWasm.google.Auth.Models;

namespace BWasm.google.Auth.ApiCalls
{
    public class AppAuthClient
    {
        private HttpClient _httpClient;
        public AppAuthClient(HttpClient httpClient)
        {
            _httpClient = httpClient;
        }

        public async Task<TokenResponseModel> RegisterGoogleUser(RegisterGoogleUserRequestModel  googleUserRequestModel)
        {
            var postData = new StringContent(JsonSerializer.Serialize(googleUserRequestModel),Encoding.UTF8,"application/json");
            var response =  await _httpClient.PostAsync("/Account/register-google-user", postData);
            response.EnsureSuccessStatusCode();

            return await response.Content.ReadFromJsonAsync<TokenResponseModel>();
        }
    }
}
  • So here invoking endpoint like '/Account/register-google-user'. Here post payload contains user information like 'firstname', 'lastname', and 'email' from the google token. Here we expect the custom JWT token of our API as the response.
Install HTTP extension NuGet.
Package Manager:
Install-Package Microsoft.Extensions.Http -Version 5.0.0
.Net CLI:
dotnet add package Microsoft.Extensions.Http --version 5.0.0
Now register our 'AppAuthClient.cs' in startup.cs along with our domain API.
Startup.cs:
builder.Services.AddHttpClient<AppAuthClient>(options => {
  options.BaseAddress = new Uri("https://localhost:6001");
});

Implement AccountClaimsPrincipalFactory In Blazor App:

Now we have to implement AccountCliamsPrincipalFactory so that we can invoke the register API. So let's create a folder like 'Providers' and then add a new class like 'CustomAccountFactory.cs'
Providers/CustomAccountFactory.cs:
using System.Linq;
using System.Security.Claims;
using System.Threading.Tasks;
using BWasm.google.Auth.ApiCalls;
using BWasm.google.Auth.Models;
using Microsoft.AspNetCore.Components.WebAssembly.Authentication;
using Microsoft.AspNetCore.Components.WebAssembly.Authentication.Internal;

namespace BWasm.google.Auth.Providers
{
    public class CustomAccountFactory
    : AccountClaimsPrincipalFactory<RemoteUserAccount>
    {
        private readonly AppAuthClient _appAuthClient;
        public CustomAccountFactory(IAccessTokenProviderAccessor accessor,
            AppAuthClient appAuthClient
            ) : base(accessor)
        {
            _appAuthClient = appAuthClient;
        }

        public async override ValueTask<ClaimsPrincipal> CreateUserAsync(
            RemoteUserAccount account, RemoteAuthenticationUserOptions options)
        {
            var initialUser = await base.CreateUserAsync(account, options);
            try
            {
                if (initialUser.Identity.IsAuthenticated)
                {
                    var googleUser = new RegisterGoogleUserRequestModel
                    {
                        Email = initialUser.Claims.Where(_ => _.Type == "email").Select(_ => _.Value).FirstOrDefault(),
                        FirstName = initialUser.Claims.Where(_ => _.Type == "given_name").Select(_ => _.Value).FirstOrDefault(),

                        LastName = initialUser.Claims.Where(_ => _.Type == "family_name").Select(_ => _.Value).FirstOrDefault()
                    };

                    var response = await _appAuthClient.RegisterGoogleUser(googleUser);
                    
                    ((ClaimsIdentity) initialUser.Identity).AddClaim(
                        new Claim("APIjwt", response.JwtToken)
                    );

                }
            }
            catch
            {
                initialUser = new ClaimsPrincipal(new ClaimsIdentity());
            }

            return initialUser;
        }
    }
}
  • (Line: 12) Inheriting 'AccountCliamsPrincipalFactory<RemoteUserAccount>'.
  • (Line: 16) Injected our typed client 'AppAuthClient'.
  • (Line: 30-36) Making payload object like 'RegisterGoogleUserRequestModel'. The data loaded into it from google authenticated claims.
  • (Line: 38) Invoking the user registration API.
  • (LIne: 40-42) Updating use claims. Added our API jwt token as one of the user claims. So by using the claim we will try to access our secure endpoints
Register our 'CustomAccountFactory' with the OpenID service in 'Program.cs'.
Program.cs:
builder.Services.AddOidcAuthentication<RemoteAuthenticationState,
RemoteUserAccount>(options =>
{
	builder.Configuration.Bind("Local", options.ProviderOptions);

	options.ProviderOptions.DefaultScopes.Add("email");
})
.AddAccountClaimsPrincipalFactory<RemoteAuthenticationState,
RemoteUserAccount, CustomAccountFactory>();
Now run both API and our blazor web assembly application and test the google user registration.



Create Secured Endpoint In Our API Project:

After login, we will have our custom JWT token. So to test the Jwt token we will create a secured endpoint in the API project.

First, let's enable the token verification service in 'Startup.cs'.
Startup.cs:
services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddJwtBearer(options =>
{
	var tokenSettings = Configuration
	.GetSection("TokenSettings").Get<TokenSettings>();
	options.TokenValidationParameters = new TokenValidationParameters
	{
		ValidIssuer = tokenSettings.Issuer,
		ValidateIssuer = true,
		ValidAudience = tokenSettings.Audience,
		ValidateAudience = true,
		IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(tokenSettings.Key)),
		ValidateIssuerSigningKey = true,
	};
});
Now register the authentication middleware just above the authorization middleware.
Startup.cs:
app.UseAuthentication();
Now let's create an example secured endpoint for our testing.
Controllers/AccountController.cs:
[Authorize]
[HttpGet]
[Route("cities")]
public IActionResult Cities()
{
	return Ok(new List<string>{"Hyderabad","Mumbai","Bangalore"});
}

Consume Secured API From Our Blazor WebAssembly Application:

Now let's write the logic in our typed client class to consume the secured endpoint.
ApiCalls/AppAuthClient.cs:
public async Task<List<string>> GetCities(string token)
{
	_httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("bearer", token);
	return await _httpClient.GetFromJsonAsync<List<string>>("/Account/cities");
}
  • Here invoking the secured endpoint by adding our jwt token as an authorization header value.
Now update 'Index.razor' component to render the sample data from the secured endpoint.
Pages/Index.razor:
@page "/"
@inject BWasm.google.Auth.ApiCalls.AppAuthClient _authClient;

<h1>Hello, world!</h1>

<AuthorizeView>
    <ul>
        @foreach (var item in cities)
        {
            <li>@item</li>
        }
    </ul>
</AuthorizeView>

@code{

    public List<string> cities = new List<string>();

    [CascadingParameter]
    private Task<AuthenticationState> authenticationState { get; set; }
    protected override async Task OnInitializedAsync()
    {
        var authState = authenticationState.Result;
        if (authState.User.Identity.IsAuthenticated)
        {
            string apiToken = authState.User.Claims.Where(_ => _.Type == "APIjwt").Select(_ => _.Value).FirstOrDefault();
            cities = await _authClient.GetCities(apiToken);
        }
    }
}
So that's all about registering the google user and generating the jwt token.

Video Session:

 

Support Me!
Buy Me A Coffee PayPal Me

Wrapping Up:

Hopefully, I think this article delivered some useful information about adding google users to the database and generating JWT Blazor Webassembly Standalone Application. I love to have your feedback, suggestions, and better techniques in the comment section below.

Refer:

Follow Me:

Comments

Popular posts from this blog

Blazor WebAssembly Custom Authentication From Scratch

In this article, we are going to explore and implement custom authentication from the scratch. In this sample, we will use JWT authentication for user authentication. Main Building Blocks Of Blazor WebAssembly Authentication: The core concepts of blazor webassembly authentication are: AuthenticationStateProvider Service AuthorizeView Component Task<AuthenticationState> Cascading Property CascadingAuthenticationState Component AuthorizeRouteView Component AuthenticationStateProvider Service - this provider holds the authentication information about the login user. The 'GetAuthenticationStateAsync()' method in the Authentication state provider returns user AuthenticationState. The 'NotifyAuthenticationStateChaged()' to notify the latest user information within the components which using this AuthenticationStateProvider. AuthorizeView Component - displays different content depending on the user authorization state. This component uses the AuthenticationStateProvider

How Response Caching Works In Asp.Net Core

What Is Response Caching?: Response Caching means storing of response output and using stored response until it's under it's the expiration time. Response Caching approach cuts down some requests to the server and also reduces some workload on the server. Response Caching Headers: Response Caching carried out by the few Http based headers information between client and server. Main Response Caching Headers are like below Cache-Control Pragma Vary Cache-Control Header: Cache-Control header is the main header type for the response caching. Cache-Control will be decorated with the following directives. public - this directive indicates any cache may store the response. private - this directive allows to store response with respect to a single user and can't be stored with shared cache stores. max-age - this directive represents a time to hold a response in the cache. no-cache - this directive represents no storing of response and always fetch the fr

Endpoint Routing In Asp.Net Core

How Routing Works In  Core 2.1 And Below Versions?: In Asp.Net Core routing is configured using app.UseRouter() or app.UseMvc() middleware. app.UseMvc(routes => { routes.MapRoute( name: "default", template: "{controller=Home}/{action=Index}/{id?}"); }); Here in Dotnet Core version 2.1 or below versions on the execution of route middleware request will be navigated appropriate controller matched to the route. An operation or functionality which is dependent on route URL or route values and that need to be implemented before the execution of route middleware can be done by accessing the route path from the current request context as below app.Use(async (context, next) => { if(context.Request.Path.Value.IndexOf("oldvehicle") != -1) { context.Response.Redirect("vehicle"); } else { await next(); } }); app.UseMvc(routes => { routes.MapRoute( name: "vehicleRoute", template: "vehicle", defaul

Asp.Net Core MVC Form Validation Techniques

Introduction: Form validations in any applications are like assures that a valid data is storing on servers. All programing frameworks have their own individual implementations for form validations. In Dotnet Core MVC application server-side validations carried on by the models with the help of Data Annotations and the client-side validations carried by the plugin jQuery Unobtrusive Validation. jQuery Unobtrusive Validation is a custom library developed by Microsoft based on the popular library  jQuery Validate . In this article, we are going to learn how the model validation and client-side validation works in Asp.Net Core MVC Application with sample examples. Getting Started: Let's create an Asp.Net Core MVC application project using preferred editors like Microsoft Visual Studio or Microsoft Visual Studio Code. Here I'm using Visual Studio. Let's create an MVC controller and name it as 'PersonController.cs' and add an action method as bel

.Net5 Web API Redis Cache Using StackExchange.Redis.Extensions.AspNetCore Library

In this article, we are going to explore the integration of Redis cache in .Net5 Web API application using the 'StackExchange.Redis.Exntensions' library. Note:- Microsoft has introduced an 'IDistributedCache' interface in dotnet core which supports different cache stores like In-Memory, Redis, NCache, etc. It is simple and easy to work with  'IDistributedCache', for the Redis store with limited features but if we want more features of the Redis store we can choose to use 'StackExchange.Redis.Extensions'.  Click here for Redis Cache Integration Using IDistributedCache Interface . Overview On StackExchange.Redis.Extnesions Library: The 'StackExchange.Redis.Extension' library extended from the main library 'StackExchange.Redis'. Some of the key features of this library like: Default serialization and deserialization. Easy to save and fetch complex objects. Search key. Multiple Database Access Setup Redis Docker Instance: For this sampl

.NET Core MVC Application File Upload To Physical Location With Buffered Technique

Buffering Technique In File Upload: The server will use its Memory(RAM) or Disk Storage to save the files on receiving a file upload request from the client.  Usage of Memory(RAM) or Disk depends on the number of file requests and the size of the file.  Any single buffered file exceeding 64KB is moved from Memory to a temp file on disk.  If an application receives heavy traffic of uploading files there might be a chance of out of Disk or RAM memory which leads to crash application. So this Buffer technique used for small files uploading. In the following article, we create a sample for the file uploading using .NET Core MVC application. Create The .NET Core MVC Project: Let's create a .NET Core MVC project, here for this sample I'm using Visual Studio Code as below.   Check the link to use the Visual Studio Code for .NET Core Application . IFormFile: Microsoft.AspNetCore.Http.IFormFile used for file upload with buffered technique. On uploading files f

.Net5 Web API Managing Files Using Azure Blob Storage

In this article, we are going to understand the different file operations like uploading, reading, downloading, and deleting in .Net5 Web API application using Azure Blob Storage. Azure Blob Storage: Azure blob storage is Microsoft cloud storage. Blob storage can store a massive amount of file data as unstructured data. The unstructured data means not belong to any specific type, which means text or binary data. So something like images or pdf or videos to store in the cloud, then the most recommended is to use the blob store. The key component to creating azure blob storage resource: Storage Account:- A Storage account gives a unique namespace in Azure for all the data we will save. Every object that we store in Azure Storage has an address. The address is nothing but the unique name of our Storage Account name. The combination of the account name and the Azure Storage blob endpoint forms the base address for each object in our Storage account. For example, if our Storage Account is n

Ionic Picker Sample Code In Angular

Introduction: Ionic Picker(ion-picker) is a popup slides up from the bottom of the device screen, which contains rows with selectable column separated items. The main building block of ion-picker as follows: PickerController PickerOptions PickerController: PickerController object helps in creating an ion-picker overlay. create(opts?: Opts): Promise<Overlay> PickerController create method helps in create the picker overlay with the picker options PickerOptions: PickerOptions is a configuration object used by PickerController to display ion-picker. Single Column Ionic Picker: single.item.picker.ts: import { Component } from "@angular/core"; import { PickerController } from "@ionic/angular"; import { PickerOptions } from "@ionic/core"; @Component({ selector: "single-column-picker", templateUrl:"single.item.picker.html" }) export class SingleItemPicker { animals: string[] = ["Tiger&quo

.Net Core HttpClient JSON Extension Methods Using System.Net.Http.Json Package

.Net Core 3.0 onwards Microsoft brought up a new package called System.Net.Http.Json. This new package provides JSON extension methods for HttpClient. These JSON extension methods will have a prebuild mechanism for serializing or deserializing response data or payload of HttpClient call. System.Net.Http.Json extension methods that are provided to HttpClient, few of them are mentioned below. GetFromJsonAsync PostAsJsonAsync PutAsJsonAsync ReadFromJsonAsync In this article, we understand System.Net.Http.Json package by implementing the HttpClient samples by with and without JSON extension methods and compare them. Create A .Net Core Web API Sample Application: Let's create a .Net Core sample Web API application, from this application we will consume another Web API by implementing HttpClient calls. We can create a Web API sample application using IDE like Visual Studio 2019(Supports .Net Core 3.0 plus) or  Visual Studio Code . Create A Typed Client: In .Net Core using the Http

GraphQL API Integration In Asp.Net Core Application

Introduction: GraphQL is a query language for your API and a server-side runtime for executing queries by using a type system you define for your data. GraphQL can be integrated into any framework like ASP.NET, Java, NestJs, etc and it isn't tied to any specific database or storage engine and is instead backed by your existing code and data. How GraphQL API Different From Rest API: GraphQL exposes a single end-point or route for the entire application, regardless of its responses or actions. HTTP-POST is the only Http verb recommended by the GraphQL. The client applications (consumers of API) can give instructions to GraphQL API about what type of properties to be returned in the response. Building Blocks Of GraphQL API: The main building blocks of GraphQL API is Schemas and Types.  A 'Schema' in GrpahQL API describes the functionality available to the clients connect to API. Schema mostly consists of GraphQL Object Types, Queries, Mutations, etc. T