Round #739

Write a Web API POST endpoint that accepts a JSON body and returns Created.

### Creating a Web API POST Endpoint in C# Below is an example of how to create a Web API POST endpoint in C# that accepts a JSON body and returns a 201 Created status code. #### Model ```csharp public class MyModel { public int Id { get; set; } public string Name { get; set; } } ``` #### Controller ```csharp using Microsoft.AspNetCore.Mvc; using System.Threading.Tasks; [ApiController] [Route("api/[controller]")] public class MyController : ControllerBase { [HttpPost] public async Task<IActionResult> Create([FromBody] MyModel model) { // Process the model here // For example, save it to a database // Return a 201 Created status code return CreatedAtAction(nameof(Create), new { id = model.Id }, model); } } ``` #### Explanation * We define a `MyModel` class to represent the JSON body. * We create a `MyController` class with a `Create` method that handles HTTP POST requests. * The `[FromBody]` attribute specifies that the `model` parameter should be deserialized from the request body. * We process the `model` as needed (e.g., save it to a database). * Finally, we return a 201 Created status code using the `CreatedAtAction` method, which also returns the created resource in the response body. #### Example Use Case To test this endpoint, you can use a tool like Postman or curl to send a POST request with a JSON body: ```json { "id": 1, "name": "John Doe" } ``` The response should be a 201 Created status code with the created resource in the response body: ```json { "id": 1, "name": "John Doe" } ``` #### Full Example with Startup Configuration Here's a full example with startup configuration: ```csharp using Microsoft.AspNetCore.Builder; using Microsoft.AspNetCore.Hosting; using Microsoft.Extensions.DependencyInjection; using Microsoft.Extensions.Hosting; public class Startup { public void ConfigureServices(IServiceCollection services) { services.AddControllers(); } public void Configure(IApplicationBuilder app, IWebHostEnvironment env) { if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); } app.UseRouting(); app.UseEndpoints(endpoints => { endpoints.MapControllers(); }); } } public class Program { public static void Main(string[] args) { CreateHostBuilder(args).Build().Run(); } public static IHostBuilder CreateHostBuilder(string[] args) => Host.CreateDefaultBuilder(args) .ConfigureWebHostDefaults(webBuilder => { webBuilder.UseStartup<Startup>(); }); } ``` This example sets up a basic ASP.NET Core Web API project with a single controller and endpoint. You can run the project and test the endpoint using a tool like Postman or curl.

```csharp using Microsoft.AspNetCore.Mvc; using Microsoft.Extensions.Logging; namespace MyApi.Controllers { [ApiController] [Route("api/[controller]")] public class MyController : ControllerBase { private readonly ILogger<MyController> _logger; public MyController(ILogger<MyController> logger) { _logger = logger; } [HttpPost] public IActionResult Create([FromBody] MyModel model) { try { // Process the model _logger.LogInformation($"Created new resource: {model}"); return CreatedAtAction(nameof(Create), model); } catch (Exception ex) { _logger.LogError(ex, "Error creating new resource"); return StatusCode(500, "Internal Server Error"); } } } public class MyModel { public string Name { get; set; } public string Description { get; set; } } } ``` In this implementation, we define a `MyController` class that handles HTTP requests. The `Create` method is decorated with the `[HttpPost]` attribute, indicating that it handles HTTP POST requests. The method takes a `MyModel` object as a parameter, which is deserialized from the JSON body of the request. We use the `ILogger<T>` interface to log information and errors. The logger is injected into the controller through the constructor. If the model is processed successfully, we return a `201 Created` response with the created resource. If an error occurs, we log the error and return a `500 Internal Server Error` response. Note that you will need to register the `MyController` class in the Startup.cs file, and also configure the routing and logging middleware. For example, in the `Startup.cs` file: ```csharp public void ConfigureServices(IServiceCollection services) { services.AddControllers(); services.AddLogging(loggingBuilder => loggingBuilder.AddConsole()); } public void Configure(IApplicationBuilder app, IWebHostEnvironment env) { app.UseRouting(); app.UseEndpoints(endpoints => { endpoints.MapControllers(); }); } ``` This will enable the Web API to handle requests and log information to the console.