In the world of .NET development, handling JSON serialization and deserialization is a common task, especially when dealing with web APIs, configuration files, and data interchange between systems. Two prominent libraries for JSON processing in the .NET ecosystem are Newtonsoft.Json (often referred to simply as Newtonsoft) and System.Text.Json. In this article, we'll compare and contrast these two libraries, exploring their features, examples, advantages, and disadvantages. Newtonsoft.Json Newtonsoft.Json, developed by James Newton-King, has been the go-to library for JSON serialization and deserialization in the .NET ecosystem for many years. It offers a wide range of features and has garnered widespread adoption among developers. Let's explore some of its characteristics:   Features of Newtonsoft.Json   Flexible and Robust: Newtonsoft.Json provides comprehensive support for JSON serialization and deserialization, handling complex object graphs, custom conversions, and nullable types effortlessly. Customization Options: Developers can customize the serialization and deserialization process using attributes, custom converters, and serialization settings, allowing fine-grained control over JSON representation. Widely Adopted: Newtonsoft.Json is battle-tested and widely adopted in the .NET community, with extensive documentation, tutorials, and community support available.   using Newtonsoft.Json; // Serialization string json = JsonConvert.SerializeObject(myObject); // Deserialization MyObject obj = JsonConvert.DeserializeObject<MyObject>(json); System.Text.Json System.Text.Json, introduced in .NET Core 3.0 and later versions, is Microsoft's built-in JSON processing library, aiming to provide a modern, high-performance alternative to Newtonsoft.Json. While it may not offer the same level of features and flexibility as Newtonsoft.Json, it focuses on performance and seamless integration with the .NET ecosystem. Features of System.Text.Json Performance: System.Text.Json is optimized for performance, offering faster serialization and deserialization compared to Newtonsoft.Json in certain scenarios. Built-in Support: It seamlessly integrates with other .NET features such as async/await, streams, and memory management, making it a natural choice for .NET Core and .NET 5+ projects. Minimalistic API: System.Text.Json provides a minimalistic API surface, emphasizing simplicity and ease of use for common scenarios. using System.Text.Json; // Serialization string json = JsonSerializer.Serialize(myObject); // Deserialization MyObject obj = JsonSerializer.Deserialize<MyObject>(json);   Advantages and Disadvantages Newtonsoft.Json Advantages Comprehensive feature set with extensive customization options. Widely adopted with a large community and ecosystem. Mature and battle-tested library. Disadvantages Performance may degrade for large datasets compared to System.Text.Json. Requires additional dependencies for .NET Core and .NET 5+ projects.    System.Text.Json Advantages Optimized for performance, especially in scenarios with large datasets. Built-in support in .NET Core and .NET 5+, eliminating the need for additional dependencies. Seamless integration with other .NET features. Disadvantages Less feature-rich compared to Newtonsoft.Json, lacking some advanced customization options. Limited community support and fewer resources compared to Newtonsoft.Json. [Benchmark] public void NewtonsoftDeserializeIndividualData() { foreach (var user in serializedTestUsersList) { _ = Newtonsoft.Json.JsonConvert.DeserializeObject<User>(user); } } [Benchmark] public void MicrosoftDeserializeIndividualData() { foreach (var user in serializedTestUsersList) { _ = System.Text.Json.JsonSerializer.Deserialize<User>(user); } } Results: Data Method Count Mean  Ratio  Allocated Alloc Ratio Newtonsoft 10000 15.974 ms 1.00 35.5 MB 1.00 Microsoft 10000 8.472 ms 1.00 3.96 MB 1.0      Conclusion In the realm of JSON serialization and deserialization within the .NET landscape, our benchmarks present a compelling case. Despite claims of high performance from Newtonsoft.Json, the results unequivocally demonstrate that Microsoft’s System.Text.Json consistently outperforms its counterpart. Whether handling large or small datasets, System.Text.Json showcases superior speed and memory efficiency.

Before diving into optimization techniques, it’s important to identify the areas of your code that require improvement. By measuring and profiling your application’s performance, you can pinpoint the exact bottlenecks and focus your optimization efforts where they matter the most (Measure and Identify Bottlenecks). In this blog, I’ll explain effective strategies for handling memory and reducing garbage collection overhead in your C# applications. Memory management and garbage collection are essential aspects of performance tuning in C#, so these best practices will help you optimize your code for maximum efficiency.  Here are 8 tips that will help with performance optimization. 1. Use the IDisposable interface :  Utilizing the IDisposable interface is a crucial C# performance tip. It helps you properly manage unmanaged resources and ensures that your application’s memory usage is efficient.  Bad way: public class ResourceHolder { private Stream _stream; public ResourceHolder(string filePath) { _stream = File.OpenRead(filePath); } // Missing: IDisposable implementation } Good way: public class ResourceHolder : IDisposable { private Stream _stream; public ResourceHolder(string filePath) { _stream = File.OpenRead(filePath); } public void Dispose() { _stream?.Dispose(); // Properly disposing the unmanaged resource. } } By implementing the IDisposable interface, you ensure that unmanaged resources will be released when no longer needed, preventing memory leaks and reducing pressure on the garbage collector. This is a fundamental code optimization technique in C# that developers should utilize. 2. Asynchronous Programming with async/await  Asynchronous programming is a powerful technique for improving C# performance in I/O-bound operations, allowing you to enhance your app’s responsiveness and efficiency. Here, we’ll explore some best practices for async/await in C#. Limit the number of concurrent operations Bad way: public async Task ProcessManyItems(List<string> items) { var tasks = items.Select(async item => await ProcessItem(item)); await Task.WhenAll(tasks); } Good way: public async Task ProcessManyItems(List<string> items, int maxConcurrency = 10) { using (var semaphore = new SemaphoreSlim(maxConcurrency)) { var tasks = items.Select(async item => { await semaphore.WaitAsync(); // Limit concurrency by waiting for the semaphore. try { await ProcessItem(item); } finally { semaphore.Release(); // Release the semaphore to allow other operations. } }); await Task.WhenAll(tasks); } } Without limiting concurrency, many tasks will run simultaneously, which can lead to heavy load and degraded overall performance. Instead, use a SemaphoreSlim to control the number of concurrent operations.  3. UseConfigureAwait(false) when possible ConfigureAwait(false) is a valuable C# performance trick that can help prevent deadlocks in your async code and improve efficiency by not forcing continuations to run on the original synchronization context.   public async Task<string> DataAsync() { var data = await ReadDataAsync().ConfigureAwait(false); // Use ConfigureAwait(false) to avoid potential deadlocks. return ProcessData(data); } 4. Parallel Computing and Task Parallel Library This will help the power of multicore processors and speed up CPU-bound operations Bad way: private void Data(List<int> data) { for (int i = 0; i < data.Count; i++) { PerformExpensiveOperation(data[i]); } } Good way: private void Data(List<int> data) { Parallel.ForEach(data, item => PerformExpensiveOperation(item)); } Parallel loops can considerably accelerate processing of large collections by distributing the workload among multiple CPU cores. Switch from regular for and foreach loops to their parallel counterparts whenever it’s feasible and safe.  5. Importance of Caching Data Utilizing in-memory caching can drastically reduce time-consuming database fetches and speed up your application. The good way demonstrates the use of in-memory caching to store product data and reduce time-consuming database fetches.  6. Optimizing LINQ Performance Force immediate execution using ToList() or ToArray() when needed. Use the AsParallel() extension method to ensure safety and parallelism. Selecting a HashSet instead of a List offers faster look-up times and greater performance 7. Task and ValueTask for reusing asynchronous code Use ValueTask to reduce heap allocations public async ValueTask<string> DataAsync() { var data = await ReadFromStreamAsync(_stream); return ProcessData(data); } By switching from Task<TResult> to ValueTask<TResult>, you can reduce heap allocations and ultimately improve your C# performance 8. Use HttpClientFactory to manage HttpClient instances private readonly HttpClient _httpClient; public MyClass(HttpClient httpClient) { _httpClient = httpClient; } public async Task GetDataAsync() { var response = await _httpClient.GetAsync("http://himashu.com/data"); } This approach manages the lifetimes of your HttpClient instances more efficiently, preventing socket exhaustion. - Use null-coalescing operators (??, ??=) string datInput = NullableString() ?? "default"; - Using Span and Memory for efficient buffer management // Using Span<T> avoids additional memory allocation and copying byte[] data = GetData(); Span<byte> dataSpan = data.AsSpan(); ProcessData(dataSpan); - Use StringComparison options for efficient string comparison bool equal = string.Equals(string1, string2, StringComparison.OrdinalIgnoreCase); - Use StringBuilder over string concatenation in loops StringBuilder sb = new StringBuilder(); for (int i = 0; i < 1000; i++) { sb.AppendFormat("Iteration: {0}", i); } string result = sb.ToString();   This has been a collection of just a few things I’ve found useful for enhancing the performance of my C# .NET code. Remember that the key to successful development is a balance between code quality and performance optimizations. By employing these techniques, you’ll be able to build high-performing C# applications that deliver a seamless user experience.

In this blog, I will explore the top useful C# .NET snippets that every developer should have in their arsenal.  From object initialization syntax to dictionary initialization, these snippets cover a wide range of functionalities that will help you streamline your C# development process. Object Initialization Syntax - By using object initialization syntax, you can quickly create and initialize objects without the need for multiple lines of code. public class Product { public string Name { get; set; } public decimal Price { get; set; } } var product = new Product { Name = "Mouse", Price = 999.00 }; Enumerable.Range Method - This snippet simplifies the process of iterating over a range of numbers in a concise and readable manner. foreach (var number in Enumerable.Range(1, 10)) { Console.WriteLine(number); } Conditional Ternary Operator - By using the conditional ternary operator, you can streamline conditional checks and make your code more compact and readable. int time = 7; var result = (time < 5) ? "Weekend" : "Working"; Console.WriteLine(result); Task.WhenAll Method - With Task.WhenAll, you can improve the performance of your asynchronous operations by running them concurrently. async Task DownloadAllAsync(List<string> urls) { var tasks = urls.Select(url => DownloadAsync(url)).ToArray(); await Task.WhenAll(tasks); } async Task DownloadAsync(string url) { Console.WriteLine($"Downloading from {url}"); } Null-Conditional Operator - By using the null-conditional operator, you can handle null values gracefully and prevent runtime exceptions in your code. string firstName = person?.FirstName ?? "Unknown"; Console.WriteLine(firstName); LINQ Query Syntax - By leveraging LINQ query syntax, you can write complex queries on collections with ease and readability. var scores = new int[] { 90, 100, 82, 89, 92 }; var highScores = from score in scores where score >= 90 select score; foreach (var score in highScores) { Console.WriteLine(score); } Using Statement - The using statement is essential for handling disposable objects and preventing resource leaks in your code. using (var streamReader = new StreamReader(@"C:\file.txt")) { string content = streamReader.ReadToEnd(); Console.WriteLine(content); } Expression-Bodied Members - By using expression-bodied members, you can make your code more concise and expressive, especially for simple properties and methods.   public class Person { public string FirstName { get; set; } public string LastName { get; set; } public string FullName => $"{FirstName} {LastName}"; // Fullname directly dynamically set at model level. } Dictionary Initialization - Dictionary initialization simplifies the process of populating key-value pairs in a dictionary with a clean and readable syntax. var capitals = new Dictionary<string, string> { ["USA"] = "Washington, D.C.", ["Japan"] = "Tokyo", ["India"] = "Delhi" };   Appending an Element to a List - C# offers numerous methods for adding items to lists. For instance, the widely-used Add() method is available. However, there are plenty of other options as well. Here are five: // Statically defined list List<int> myList = new List<int> {2, 5, 6}; // Appending using Add() myList.Add(5); // [2, 5, 6, 5] // Appending using AddRange() myList.AddRange(new List<int> {9}); // [2, 5, 6, 5, 9] // Appending using Insert() myList.Insert(myList.Count, -4); // [2, 5, 6, 5, 9, -4] // Appending using InsertRange() myList.InsertRange(myList.Count, new List<int> {3}); // [2, 5, 6, 5, 9, -4, 3] // To Check if a List Is Empty List<int> myList = new List<int>(); // Check if a list is empty by its Count if (myList.Count == 0) { // the list is empty } // Check if a list is empty by its type flexibility **preferred method** if (!myList.Any()) { // the list is empty } String Interpolation (Formatting a String) - Oftentimes, we need to format strings to display information in a more readable or structured manner. Here are some options: string name = "Himanshu"; int age = 25; // String formatting using concatenation Console.WriteLine("My name is " + name + ", and I am " + age + " years old."); // String formatting using composite formatting Console.WriteLine("My name is {0}, and I am {1} years old.", name, age); // String formatting using interpolation (C# 6.0+) Console.WriteLine($"My name is {name}, and I am {age} years old"); These are but a small example of the power and flexibility that C# and .NET bring to the table.Thank you for reading! We hope these C# .NET snippets will help you streamline your development process and boost your productivity.

To utilize custom fonts from your Dotnet codebase in HTML or PDF documents, follow these steps: Add the fonts you intend to use for your PDF or HTML documents. Ensure they are in the .ttf extension format. <PackageReference Include="Polybioz.HtmlRenderer.PdfSharp.Core" Version="1.0.0">   Include the necessary package by adding the following line to your project file: Initialize the IServiceCollection to utilize the CustomFontResolver class. You can achieve this by adding the following extension method:   public static class IServicesCollectionExtension { public static IServiceCollection InitializeDocumentProcessor(this IServiceCollection services) { GlobalFontSettings.FontResolver = new CustomFontResolver(); return services; } } Initialize the class in your program file:   builder.Services.InitializeDocumentProcessor();   Specify the DefaultFontName you wish to use. You can also manage bold and italic styles. public class CustomFontResolver : IFontResolver { string IFontResolver.DefaultFontName => "Rubik"; public FontResolverInfo ResolveTypeface(string familyName, bool isBold, bool isItalic) { if (isBold) { if (isItalic) { return new FontResolverInfo("Rubik#bi"); } return new FontResolverInfo("Rubik#b"); } if (isItalic) return new FontResolverInfo("Rubik#i"); return new FontResolverInfo("Rubik"); } public byte[] GetFont(string faceName) { switch (faceName) { case "Rubik": return CustomFontHelper.Rubik; case "Rubik#b": return CustomFontHelper.RubikBold; case "Rubik#bi": return CustomFontHelper.RubikBoldItalic; case "Rubik#i": return CustomFontHelper.RubikItalic; } return GetFont(faceName); } }   Define a helper class CustomFontHelper to facilitate loading font data. Ensure you have added the fonts for all the types you intend to use. public static class CustomFontHelper { public static byte[] Rubik { get { return LoadFontData("Rubik-Light.ttf"); } } public static byte[] RubikBold { get { return LoadFontData("Rubik-SemiBold.ttf"); } } public static byte[] RubikBoldItalic { get { return LoadFontData("Rubik-SemiBoldItalic.ttf"); } } public static byte[] RubikItalic { get { return LoadFontData("Rubik-Italic.ttf"); } } static byte[] LoadFontData(string name) { using (Stream stream = File.OpenRead("Fonts/" + name)) { if (stream == null) throw new ArgumentException("No resource with name " + name); int count = (int)stream.Length; byte[] data = new byte[count]; stream.Read(data, 0, count); return data; } } } By following these steps, you can seamlessly integrate custom fonts into your HTML and PDF documents from your Dotnet codebase, without needing to specify the font-family in the HTML directly. You can also pass font styles directly through code.

Simplifying API Responses with AutoWrapper.Core in .NET Core. Handling API responses effectively is a crucial aspect of building robust and user-friendly applications. In .NET Core applications, the AutoWrapper.Core library comes to the rescue, providing a streamlined way to structure and standardize API responses. In this blog post, we'll explore how to use AutoWrapper.Core to create fixed responses for different status codes in your API. Firstly, you'll need to install the AutoWrapper.Core NuGet package. Add the following line to your project's .csproj file: <PackageReference Include="AutoWrapper.Core" Version="4.5.1" /> This package simplifies the process of handling API responses and ensures a consistent format for success, error, and data messages.   Example: Login Method Let's consider a common scenario, the login method, where we want to ensure fixed responses for both successful and unsuccessful attempts. [HttpPost("Login")] public async Task<ApiResponse> Login([FromBody] Login model) { var user = await _userService.GetUserByName(model.UserName); if (user != null && await _userService.CheckUserPassword(user, model.Password)) { var userResponse = await _tokenService.GenerateToken(user); return new ApiResponse(message: "Login Successfully.", result: userResponse, statusCode: 200); } return new ApiResponse(message: "Invalid Credential.", result: null, statusCode: 401); } In this example, we're using AutoWrapper.Core's ApiResponse class to encapsulate our responses. For a successful login attempt (status code 200), we return a positive message along with the user response. In case of invalid credentials (status code 401), an appropriate error message is provided. ApiResponse Class Now, let's take a closer look at the ApiResponse class from AutoWrapper.Core: namespace AutoWrapper.Wrappers; public class ApiResponse { public string Version { get; set; } [JsonProperty(DefaultValueHandling = DefaultValueHandling.Ignore)] public int StatusCode { get; set; } public string Message { get; set; } [JsonProperty(DefaultValueHandling = DefaultValueHandling.Ignore)] public bool? IsError { get; set; } public object ResponseException { get; set; } public object Result { get; set; } [JsonConstructor] public ApiResponse(string message, object result = null, int statusCode = 200, string apiVersion = "1.0.0.0") { StatusCode = statusCode; Message = message; Result = result; Version = apiVersion; } public ApiResponse(object result, int statusCode = 200) { StatusCode = statusCode; Result = result; } public ApiResponse(int statusCode, object apiError) { StatusCode = statusCode; ResponseException = apiError; IsError = true; } public ApiResponse() { } } The ApiResponse class provides flexibility in constructing responses with different components such as the message, result, and status code. It helps maintain a standardized format for all API responses. Create a Custom Wrapper: AutoWrapper allows you to create a custom wrapper by implementing the IApiResponse interface. You can create a class that implements this interface to customize the fixed response. Here's an example: Create a Custom Wrapper: AutoWrapper allows you to create a custom wrapper by implementing the IApiResponse interface. You can create a class that implements this interface to customize the fixed response. Here's an example: using AutoWrapper.Wrappers; public class CustomApiResponse<T> : ApiResponse<T> { public string CustomProperty { get; set; } public CustomApiResponse(T result, string customProperty) : base(result) { CustomProperty = customProperty; } } Configure AutoWrapper: In your Startup.cs file, configure AutoWrapper to use your custom wrapper. You can do this in the ConfigureServices method: services.AddAutoWrapper(config => { config.UseCustomSchema<CustomApiResponse<object>>(); }); Replace CustomApiResponse<object> with the custom wrapper class you created. Use Custom Wrapper in Controller Actions: Now, you can use your custom wrapper in your controller actions. For example: [ApiController] [Route("api/[controller]")] public class MyController : ControllerBase { [HttpGet] public IActionResult Get() { // Your logic here var data = new { Message = "Hello, World!" }; // Use the custom wrapper var response = new CustomApiResponse<object>(data, "CustomProperty"); return Ok(response); } } Customize the CustomApiResponse according to your needs, and use it in your controller actions. This way, you can integrate AutoWrapper with other packages and customize the fixed response format in your .NET application.   In conclusion, by incorporating AutoWrapper.Core into your .NET Core applications, you can simplify the handling of API responses, making your code more readable, maintainable, and user-friendly. Consider adopting this approach to enhance the overall developer experience and ensure consistency in your API communication.

  To set up the AWS Cognito for the registration/login flow, follow these steps: First Flow: User Registration in Cognito1. Install the following NuGet packages in your .NET project:   <PackageReference Include="Amazon.AspNetCore.Identity.Cognito" Version="3.0.1" /> <PackageReference Include="Amazon.Extensions.Configuration.SystemsManager" Version="5.0.0" /> <PackageReference Include="AWSSDK.SecretsManager" Version="3.7.101.27" /> Declare AWS configuration values in appsettings: "Region": "me-south-1", "UserPoolClientId": "UserPoolClientId", "UserPoolClientSecret": "UserPoolClientSecret", "UserPoolId": "me-south-pool"   Additional Configuration Add authentication in program/startup files to enable sign-in with Cognito. 2. Create a CognitoUserPool with a unique ID in the controller: private readonly CognitoUserPool _pool; private readonly CognitoUserManager<CognitoUser> _userManager; var user = _pool.GetUser(registerUserRequest.LoginId); 3.Add user attributes (email, phone number, custom attributes) using user.Attributes.Add().   user.Attributes.Add(CognitoAttribute.Email.AttributeName, registerUserRequest.Email); user.Attributes.Add(CognitoAttribute.PhoneNumber.AttributeName, registerUserRequest.Mobile); user.Attributes.Add("custom:branch_code", registerUserRequest.BranchCode); user.Attributes.Add("custom:preferred_mode", preferedMode); 4. Create the user: cognitoResponse = await _userManager.CreateAsync(user, registerUserRequest.Password); Check cognitoResponse.Succeeded to determine if the user was created successfully.   Second Flow: User Login with Cognito 1.Search for the user in Cognito using the login ID: var cognitoUser = await _userManager.FindByIdAsync(loginUserRequest.LoginId);   2.Set a password for the Cognito model: var authRequest = new InitiateSrpAuthRequest {    Password = loginUserRequest.Password };   3.Use StartWithSrpAuthAsync to get the session ID: var authResponse = await cognitoUser.StartWithSrpAuthAsync(authRequest);   4.Add MFA method and validate using MFA auth if needed. For MFA validation, set the MFA settings in Cognito:v ar authRequest = new RespondToMfaRequest {        SessionID = validateLoginUserRequest.SessionId,        MfaCode = validateLoginUserRequest.Otp,        ChallengeNameType = ChallengeNameType.SMS_MFA }; authResponse = await cognitoUser.RespondToMfaAuthAsync(authRequest);   Extract tokens from Cognito: authResponse.AuthenticationResult.IdToken authResponse.AuthenticationResult.RefreshToken   Forgot Password Flow 1.Search for the user with LoginId in Cognito and call ForgotPasswordAsync: var user = await _userManager.FindByIdAsync(loginUserRequest.LoginId); await user.ForgotPasswordAsync();   2.Optionally, call ConfirmForgotPassword method in Cognito. _userManager.ConfirmForgotPassword(userID, token, newPassword, CancellationToken cancellationToken) Here, understanding AWS Cognito Authentication Methods and Utilizing Them as Needed.  

Hosting an Angular application on IIS involves a few straightforward steps.    Follow this step-by-step guide to seamlessly deploy your Angular project on IIS. Step 1: Open Your Angular Project in Visual Studio Code Review the build command in the package.json file. By default, it's usually set to ng build. Step 2: Run the Build Command Execute the ng build command in the terminal to compile your Angular application.  This command creates a 'dist' folder, typically located at the specified output path in the angular.json file. Step 3: Install IIS Ensure that IIS is installed on your machine. You can install it through the "Turn Windows features on or off" option in the Control Panel. Step 4: Create a New Site in IIS Open the IIS Manager. In the Connections pane, right-click on the "Sites" node and select "Add Website." Fill in the required information, such as the Site name, Physical path to the folder , and choose a port. Step 5: Configure URL Rewrite (Optional) If your Angular application uses routing, consider configuring URL Rewrite for proper routing.  Create a 'web.config' file in your 'dist' folder with the appropriate configurations. Here's a simple example of a web.config file for an Angular application with routing.This file helps configure how the server handles URL requests. ---------------------------------------------------------------------------------------------------------------- <?xml version="1.0" encoding="utf-8"?> <configuration>   <system.webServer>     <rewrite>       <rules>         <rule name="Angular Routes" stopProcessing="true">           <match url=".*" />           <conditions logicalGrouping="MatchAll">             <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />             <add input="{REQUEST_FILENAME}" matchType="IsDirectory" negate="true" />           </conditions>           <action type="Rewrite" url="/" />         </rule>       </rules>     </rewrite>     <staticContent>       <remove fileExtension=".json" />       <mimeMap fileExtension=".json" mimeType="application/json" />     </staticContent>   </system.webServer> </configuration> ---------------------------------------------------------------------------------------------------------------- Step 6: Restart IIS After making these changes, restart IIS to apply the configurations. Step 7: Access Your Angular Application Open a web browser and navigate to http://localhost:yourport (replace 'yourport' with the specified port from Step 4). Now, your Angular application is hosted on IIS. Access it through the specified port. If any issues arise, check the IIS logs for more information.  Customize these instructions based on your specific requirements and environment. Thanks!

In this blog, I will be sharing insights on how to effectively manage Conditional Authorization and Swagger Customization.   Case 1   I'm currently working on a problem our QA team found while testing our website. Specifically, there's an issue with one of the features in the application that uses an API. In the QA environment, we need to allow access without authentication, but in the production environment, authentication is required. To fix this, I added a feature called Conditional Authorize Attribute with help of Environment Variable. This feature lets us control access to the API based on the environment. It allows anonymous access when necessary.   In my situation, I've added a environment variable setting called "ASPNETCORE_ENVIRONMENT" to "QA" in the testing site's pipeline. Because of this, I can use the API on the QA server without requiring authentication.   This method also helps specific authorization rules for the API based on the environment.   Case 2 Additionally, I've added Swagger requests into a value object to meet specific requirements on swagger. By extending the Swashbuckle Swagger IOperationFilter, I integrated logic tailored to our needs. This approach allows us to customize requests in Swagger for all APIs directly.   Furthermore, I've implemented a middleware designed to handle responses and here's how it works. In my case, there are three kinds of response class in my code that specify the response type (like ApiErrorResponse, ValidatorResponse, ResponseModel). According to the requirements, when we get a 200-status code with the correct response class model, I need to wrap the response object in a value format. I created a middleware for this. It figures out which endpoint we're dealing with through the HttpContext. Using that endpoint, I grab the metadata related to the ProducesResponseTypeAttribute class and check for a status code of OK (Metadata Extraction). If I manage to get the metadata with a status code of 200, I include that response in value format. Otherwise, I stick with the same model response. This helps you to modify the response as per needed outcome. These implementations provide a flexible solution for conditionally authorizing API access and wrapping request/response in an object according to specified requirements.

Here, I will explain how to restrict users from using expired tokens in a .NET Core application. Token expiration checks are crucial for ensuring the security of your application.   Here's a general outline of how you can achieve this: 1. Configure Token Expiration: When generating a token, such as a JWT, set an expiration time for the token. This is typically done during token creation. For example, when using JWTs, you can specify the expiration claim:   var tokenDescriptor = new SecurityTokenDescriptor {     Expires = DateTime.Now.AddMinutes(30) // Set expiration time }; 2. Token Validation Middleware: Create middleware in your application to validate the token on each request. This middleware should verify the token's expiration time. You can configure this middleware in the startup or program file on the .NET side.   public void Configure(IApplicationBuilder app, IHostingEnvironment env) {     app.UseMiddleware<TokenExpirationMiddleware>(); } 3. Token Expiration Middleware: Develop middleware to validate the token's expiration time. Take note of the following points: ValidateIssuerSigningKey: Set to true, indicating that the system should validate the issuer signing key. IssuerSigningKey: The byte array represents the secret key used for both signing and verifying the JWT token. ValidateIssuer and ValidateAudience: Set to false, indicating that validation of the issuer and audience is skipped. By setting ClockSkew to TimeSpan.Zero, you specify no tolerance for clock differences. If the current time on the server or client is not precisely within the token's validity period, the token is considered expired.      public class TokenExpirationMiddleware     {         private readonly RequestDelegate _next;         public TokenExpirationMiddleware(RequestDelegate next)         {             _next = next;         }         public async Task Invoke(HttpContext context)         {             // Check if the request has a valid token             var token = context.Request.Headers["Authorization"].FirstOrDefault()?.Split(" ").Last();             if (token != null)             {                 var tokenHandler = new JwtSecurityTokenHandler();                 var key = Encoding.ASCII.GetBytes("YourSecretKey"); // Replace with your actual secret key of Issuer                 var tokenValidationParameters = new TokenValidationParameters                 {                     ValidateIssuerSigningKey = true,                     IssuerSigningKey = new SymmetricSecurityKey(key),                     ValidateIssuer = false,                     ValidateAudience = false,                     ClockSkew = TimeSpan.Zero                 };                 try                 {                     // Validate the token                     var principal = tokenHandler.ValidateToken(token, tokenValidationParameters, out var securityToken);                     // Check if the token is expired                     if (securityToken is JwtSecurityToken jwtSecurityToken)                     {                         if (jwtSecurityToken.ValidTo < DateTime.Now)                         {                             // Token is expired                             context.Response.StatusCode = (int)HttpStatusCode.Unauthorized;                             return;                         }                     }                 }                 catch (SecurityTokenException)                 {                     // Token validation failed                     context.Response.StatusCode = (int)HttpStatusCode.Unauthorized;                     return;                 }             }             await _next(context);         }     } Working fine with proper token time. Here is an example: I am providing an expired token, and it will result in a 401 Unauthorized status. You can also check the token in https://jwt.io/ for time expired (exp) . By following these steps, you can effectively implement checks to ensure that users are not able to use expired tokens within your .NET Core application.