Develop Reference

My ASP.NET Core's ApiController is not functional - JS Fetch returns 404

So I have my endpoint defined like the following:
[ApiController]
[Route("load/stuff")]
public class SignUp : ControllerBase
{
IGoogleRecaptchaV3Service _gService { get; set; }
public SignUp(IGoogleRecaptchaV3Service gService)
{
_gService = gService;
}
[HttpPost]
public async Task<IActionResult> Post([FromQuery] SignUpModel SignUpData, GRequestModel.Factory grequestFactory)
{
GRequestModel grm = grequestFactory("resValue", "remipValue");
_gService.InitializeRequest(grm);
if (!await _gService.Execute())
{
//return error codes string.
return Ok(_gService.Response.error_codes);
}
//call Business layer
return base.Content("Content here", "text/html");
}
}
This should return the HTML content if the reCAPTCHA score is human-like.
Let me know how to debug this further and whether any further code is required.
UPDATE fetch JS Code
function loadStuff() {
if (location.pathname === "/test") {
grecaptcha.execute('recaptchasitekeyhere', { action: 'onloadafterdelay' }).then(function (token) {
console.log(token);
return fetch("/load/stuff?RecaptchaToken=" + token, {
method: "POST",
body: token,
})
}).then((response) => {
// console.log works here too
if (!response.ok) {
const errorBuild = {
type: "Error",
message: response.message || "Something went wrong",
data: response.data || "",
code: response.code || "",
};
console.log("Error: " + JSON.stringify(errorBuild));
}
response.text().then(body => {
//console.log(body);
document.getElementById("test1").innerHTML = body.split(' ')[0];
document.getElementById("test2").innerHTML = body.split(' ')[1];
});
}
)
}
}
I also added this in the program.cs file:
builder.Services.AddControllers();
// FIX TEST
builder.Services.AddTransient<GRequestModel.Factory>(serviceProvider =>
(string res, string remip) => new GRequestModel(serviceProvider.GetRequiredService<IConfiguration>(), res, remip));
//Register dependencies
builder.Services.AddRazorPages();
// REMOVE ME IN PRODUCTION, USE DI INSTEAD
// ....
Configuration = app.Configuration;
// ...
public partial class Program
{
internal static IConfiguration Configuration { get; private set; }
}
I added that code above as a temporary fix, but then I tried to implement dependency injection for the IConfiguration and my codebase got dirty. I'm still a beginner in C# and I'm learning by trial and error hence so many mistakes.

Hide parameter from Swagger (Swashbuckle)

I have a C# .NET 5.0 ASP.NET Core Web API application with "Enable OpenAPI support" selected. I want to hide the optional parameter in the below example from what shows up on the swagger page. I have found numerous posts about hiding a property or the controller but none of these solutions seem to work for just the parameter in the given code:
[HttpGet]
[Route("search")]
[Authorize]
public async Task<IActionResult> Search(string query, string optional = "")
{
return OK();
}

You can create a custom attibute and an operation filter inhering from Swashbuckle.AspNetCore.SwaggerGen.IOperationFilter to exclude the desired parameters from swagger.json generation
public class OpenApiParameterIgnoreAttribute : System.Attribute
{
}
public class OpenApiParameterIgnoreFilter : Swashbuckle.AspNetCore.SwaggerGen.IOperationFilter
{
public void Apply(Microsoft.OpenApi.Models.OpenApiOperation operation, Swashbuckle.AspNetCore.SwaggerGen.OperationFilterContext context)
{
if (operation == null || context == null || context.ApiDescription?.ParameterDescriptions == null)
return;
var parametersToHide = context.ApiDescription.ParameterDescriptions
.Where(parameterDescription => ParameterHasIgnoreAttribute(parameterDescription))
.ToList();
if (parametersToHide.Count == 0)
return;
foreach (var parameterToHide in parametersToHide)
{
var parameter = operation.Parameters.FirstOrDefault(parameter => string.Equals(parameter.Name, parameterToHide.Name, System.StringComparison.Ordinal));
if (parameter != null)
operation.Parameters.Remove(parameter);
}
}
private static bool ParameterHasIgnoreAttribute(Microsoft.AspNetCore.Mvc.ApiExplorer.ApiParameterDescription parameterDescription)
{
if (parameterDescription.ModelMetadata is Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.DefaultModelMetadata metadata)
{
return metadata.Attributes.ParameterAttributes.Any(attribute => attribute.GetType() == typeof(OpenApiParameterIgnoreAttribute));
}
return false;
}
}
Put it in your controller's parameter
[HttpGet]
[Route("search")]
[Authorize]
public async Task<IActionResult> Search(string query, [OpenApiParameterIgnore] string optional = "")
{
return Ok();
}
Then configure it in Status.cs
services.AddSwaggerGen(c =>
{
c.SwaggerDoc("v1", new OpenApiInfo { Title = "My API Title", Version = "v1" });
c.OperationFilter<OpenApiParameterIgnoreFilter>();
});

POST model binding isn't working with Namespace Routing Convention with .net core c#

I've been trying to use Namespace routing to build some APIs dynamically without the need to worry about hardcoding the routes. However, I did find an example from MSDN to use namespaces and folder structure as your API structure. Here's the sample that I have to use Namespace routing:
public class NamespaceRoutingConvention : Attribute, IControllerModelConvention
{
private readonly string _baseNamespace;
public NamespaceRoutingConvention(string baseNamespace)
{
_baseNamespace = baseNamespace;
}
public void Apply(ControllerModel controller)
{
var hasRouteAttributes = controller.Selectors.Any(selector => selector.AttributeRouteModel != null);
if (hasRouteAttributes)
{
return;
}
var namespc = controller.ControllerType.Namespace;
if (namespc == null) return;
var templateParts = new StringBuilder();
templateParts.Append(namespc, _baseNamespace.Length + 1, namespc.Length - _baseNamespace.Length - 1);
templateParts.Replace('.', '/');
templateParts.Append("/[controller]/[action]/{environment}/{version}");
var template = templateParts.ToString();
foreach (var selector in controller.Selectors)
{
selector.AttributeRouteModel = new AttributeRouteModel()
{
Template = template
};
}
}
}
And here's the controller:
namespace Backend.Controllers.Api.Project.Core
{
public class UserController : ApiBaseController
{
public UserController()
{
}
[HttpPost]
public IActionResult Login(LoginInput loginInput) // <-- loginInput properties return null
{
if (!ModelState.IsValid) return BadRequest();
return Ok(user);
}
}
}
in Startup.cs
namespace Backend
{
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
// Let's use namespaces as the routing default way for our APIs
services.AddControllers(options =>
{
options.Conventions.Add(new NamespaceRoutingConvention(typeof(Startup).Namespace + ".Controllers"));
});
}
}
}
Everything works ok except that when I trigger a POST api call to Login action the LoginInput doesn't get populated the values I'm sending through Postman i.e. {"username": "value", "password": "sample"} and it always returns null value. I'm not sure what am I doing wrong with the NamespaceRoutingConvention. Bear in mind if I remove it and hard-code the route in the controller like:
[ApiController]
[Route("api/project/core/[controller]/[action]/proda/v1")]
It works as expected. Any ideas?

Try to use this instead:
[HttpPost]
public IActionResult Login([FromBody]LoginInput loginInput)
{
if (!ModelState.IsValid) return BadRequest();
return Ok(user);
}
I think that by setting AttributeRouteModel, you're preventing the middleware invoked by having ApiControllerAttribute in the Controller to do its job, and so the defaults of treating object parameters as body is not applied.
This is a guess though, I haven't been able to find the corresponding code in the source code.

Force reload of ResponseCache in .NET Core 2.1 when request data changes

I am using the following attribute [ResponseCache(Duration = 60)] to cache a specific GET Request which is called a lot on my backend in .NET Core.
Everything is working fine except the cache isn't reloaded when some data in database has changed within the 60 seconds.
Is there a specific directive I have to set to reload/update the cache? link
Example Code Snippet from my Controller:
[HttpGet]
[ResponseCache(Duration = 60)]
public ActionResult<SomeTyp[]> SendDtos()
{
var dtos = _repository.QueryAll();
return Ok(dtos);
}

There is a solution with a usage of "ETag", "If-None-Match" HTTP headers. The idea is using a code which can give us an answer to the question: "Did action response changed?".
This can be done if a controller completely owns particular data lifetime.
Create ITagProvider:
public interface ITagProvider
{
string GetETag(string tagKey);
void InvalidateETag(string tagKey);
}
Create an action filter:
public class ETagActionFilter : IActionFilter
{
private readonly ITagProvider _tagProvider;
public ETagActionFilter(ITagProvider tagProvider)
{
_tagProvider = tagProvider ?? throw new ArgumentNullException(nameof(tagProvider));
}
public void OnActionExecuted(ActionExecutedContext context)
{
if (context.Exception != null)
{
return;
}
var uri = GetActionName(context.ActionDescriptor);
var currentEtag = _tagProvider.GetETag(uri);
if (!string.IsNullOrEmpty(currentEtag))
{
context.HttpContext.Response.Headers.Add("ETag", currentEtag);
}
}
public void OnActionExecuting(ActionExecutingContext context)
{
var uri = GetActionName(context.ActionDescriptor);
var requestedEtag = context.HttpContext.Request.Headers["If-None-Match"];
var currentEtag = _tagProvider.GetETag(uri);
if (requestedEtag.Contains(currentEtag))
{
context.HttpContext.Response.Headers.Add("ETag", currentEtag);
context.Result = new StatusCodeResult(StatusCodes.Status304NotModified);
}
}
private string GetActionName(ActionDescriptor actionDescriptor)
{
return $"{actionDescriptor.RouteValues["controller"]}.{actionDescriptor.RouteValues["action"]}";
}
}
Initialize filter in Startup class:
public void ConfigureServices(IServiceCollection services)
{
// code above
services.AddMvc(options =>
{
options.Filters.Add(typeof(ETagActionFilter));
});
services.AddScoped<ETagActionFilter>();
services.AddSingleton<ITagProvider, TagProvider>();
// code below
}
Use InvalidateETag method somewhere in controllers (in the place where you modifing data):
[HttpPost]
public async Task<ActionResult> Post([FromBody] SomeType data)
{
// TODO: Modify data
// Invalidate tag
var tag = $"{controllerName}.{methodName}"
_tagProvider.InvalidateETag(tag);
return NoContent();
}
This solution may require a change of a client side. If you are using fetch, you can use, for example, the following library: https://github.com/export-mike/f-etag.
P.S. I didn't specify an implementation of the ITagProvider interface, you will need to write your own.
P.P.S. Articles about ETag and caching: https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching, https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag

API File Upload using HTTP content not exposed in swagger

I am implementing a swagger interface into an existing web API. The current API controller exposes an async upload function which uses the Request.Content to transport an image asynchronously. The code that has been used is explained in this article.
My api controller:
[HttpPost]
[Route("foo/bar/upload")]
public async Task<HttpResponseMessage> Upload()
{
if (!Request.Content.IsMimeMultipartContent())
{
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
}
var provider = await Request.Content.ReadAsMultipartAsync(new InMemoryMultipartFormDataStreamProvider());
NameValueCollection formData = provider.FormData;
HttpResponseMessage response;
//access files
IList<HttpContent> files = provider.Files;
if (files.Count > 0)
{
HttpContent file1 = files[0];
using (Stream input = await file1.ReadAsStreamAsync())
{
object responseObj = ExternalProcessInputStream(input)
response = Request.CreateResponse(HttpStatusCode.OK, responseObj);
}
}
else
{
response = Request.CreateResponse(HttpStatusCode.BadRequest);
}
return response;
}
This works dandy, but when i expose this through swagger i have a parameterless function, which returns an error when used.
My question is how can supply a proper value to test this method with?

You'll need to add a custom IOperationFilter to handle this.
Given you have a controller like so:
[ValidateMimeMultipartContentFilter]
[HttpPost, Route("softwarepackage")]
public Task<SoftwarePackageModel> UploadSingleFile()
{
var streamProvider = new MultipartFormDataStreamProvider(ServerUploadFolder);
var task = Request.Content.ReadAsMultipartAsync(streamProvider).ContinueWith<SoftwarePackageModel>(t =>
{
var firstFile = streamProvider.FileData.FirstOrDefault();
if (firstFile != null)
{
// Do something with firstFile.LocalFileName
}
return new SoftwarePackageModel
{
};
});
return task;
}
You then need to create an Swashbuckle.Swagger.IOperationFilter to add a file upload parameter to your function like:
public class FileOperationFilter : IOperationFilter
{
public void Apply(Operation operation, SchemaRegistry schemaRegistry, ApiDescription apiDescription)
{
if (operation.operationId.ToLower() == "softwarepackage_uploadsinglefile")
{
if (operation.parameters == null)
operation.parameters = new List<Parameter>(1);
else
operation.parameters.Clear();
operation.parameters.Add(new Parameter
{
name = "File",
#in = "formData",
description = "Upload software package",
required = true,
type = "file"
});
operation.consumes.Add("application/form-data");
}
}
}
And in your Swagger config you'll need to register the filter:
config.EnableSwagger(c => {... c.OperationFilter<FileOperationFilter>(); ... });
To top this up, I also added a FilterAttribute to filter out Multipart content:
public class ValidateMimeMultipartContentFilter : ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
if (!actionContext.Request.Content.IsMimeMultipartContent())
{
throw new HttpResponseException(HttpStatusCode.UnsupportedMediaType);
}
}
public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
{
}
}