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How to hook into the Asp.Net Core 6 MVC route system to customize urls generation

In the old .Net Framework MVC implementations, I was creating routes by myself so that I could also influence urls generation. Part of the code:
public class RouteBase : Route
{
public RouteBase(string url, IRouteHandler routeHandler) : base(url, routeHandler) { }
public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
{
if (Url.Contains("{segment}") && !values.ContainsKey("segment"))
values["segment"] = requestContext.HttpContext.Items["segmentValue"];
return base.GetVirtualPath(requestContext, values);
}
}
Thanks to GetVirtualPath, I was able to detect a particular segment in the route template and inject a proper value in the route values dictionary so that the client app did not have to specify it when calling for instance Url.RouteUrl(routeName).
In asp.net core 6, I'm now using attributes based routing and I don't know how to hook into this so that I can inject some value into the route values dictionary when I generate urls. If I have a route template like so:
[Route("{segment}/test", Name = "name"]
When I call this, I want an injection mechanism from somewhere else in the code so that the known segment value is injected into the route values used to build the url:
var url = Url.RouteUrl("name"); // Not passing new { segment = value } as second param
For information, I simply use this in Startup:
app.MapControllers();

You can create and register a custom UrlHelper. It will give you the ability to manipulate the behavior as per your use case:
public class CustomUrlHelper : UrlHelper
{
public CustomUrlHelper(ActionContext actionContext)
: base(actionContext) { }
public override string? RouteUrl(UrlRouteContext routeContext)
{
// if(routeContext.RouteName == "name" && routeContext.Values....)
// routeContext.Values = ....
return base.RouteUrl(routeContext);
}
}
public class CustomUrlHelperFactory : IUrlHelperFactory
{
public IUrlHelper GetUrlHelper(ActionContext context)
{
return new CustomUrlHelper(context);
}
}
and in your Program.cs:
builder.Services.AddSingleton<IUrlHelperFactory, CustomUrlHelperFactory>();
Then by calling the Url.RouteUrl("name"), your CustomUrlHelper will be called.

Amir's answer put me on track to find a solution (bounty award for him). Creating a custom UrlHelper was the way to go, but not with a UrlHelper derived class. For enpoint routing, the framework is using the sealed EndpointRoutingUrlHelper class. So I just needed to derive from UrlHelperBase, paste the code from EndpointRoutingUrlHelper and add my customizations. I was lucky that there were no internal pieces of code in there...
Here is the solution. Note that:
the term "segment" mentioned in the original question is replaced by what I actually have in my code i.e. "lang".
HttpContext.Items["lang"] is set by a middleware.
using Microsoft.AspNetCore.Mvc.Routing;
using Microsoft.AspNetCore.Mvc;
// The custom UrlHelper is registered with serviceCollection.AddSingleton<IUrlHelperFactory, LanguageAwareUrlHelperFactory>();
public class LanguageAwareUrlHelperFactory : IUrlHelperFactory
{
private readonly LinkGenerator _linkGenerator;
public LanguageAwareUrlHelperFactory(LinkGenerator linkGenerator)
{
_linkGenerator = linkGenerator;
}
public IUrlHelper GetUrlHelper(ActionContext context)
{
return new LanguageAwareUrlHelper(context, _linkGenerator);
}
}
// Source code is taken from https://github.com/dotnet/aspnetcore/blob/main/src/Mvc/Mvc.Core/src/Routing/EndpointRoutingUrlHelper.cs
// and modified to inject the desired route value
public class LanguageAwareUrlHelper : UrlHelperBase
{
private readonly LinkGenerator _linkGenerator;
public LanguageAwareUrlHelper(ActionContext actionContext, LinkGenerator linkGenerator) : base(actionContext)
{
if (linkGenerator == null)
throw new ArgumentNullException(nameof(linkGenerator));
_linkGenerator = linkGenerator;
}
public override string? Action(UrlActionContext urlActionContext)
{
if (urlActionContext == null)
throw new ArgumentNullException(nameof(urlActionContext));
var values = GetValuesDictionary(urlActionContext.Values);
if (urlActionContext.Action == null)
{
if (!values.ContainsKey("action") && AmbientValues.TryGetValue("action", out var action))
values["action"] = action;
}
else
values["action"] = urlActionContext.Action;
if (urlActionContext.Controller == null)
{
if (!values.ContainsKey("controller") && AmbientValues.TryGetValue("controller", out var controller))
values["controller"] = controller;
}
else
values["controller"] = urlActionContext.Controller;
if (!values.ContainsKey("lang") && ActionContext.HttpContext.Items.ContainsKey("lang"))
values["lang"] = ActionContext.HttpContext.Items["lang"];
var path = _linkGenerator.GetPathByRouteValues(
ActionContext.HttpContext,
routeName: null,
values,
fragment: urlActionContext.Fragment == null ? FragmentString.Empty : new FragmentString("#" + urlActionContext.Fragment));
return GenerateUrl(urlActionContext.Protocol, urlActionContext.Host, path);
}
public override string? RouteUrl(UrlRouteContext routeContext)
{
if (routeContext == null)
throw new ArgumentNullException(nameof(routeContext));
var langRouteValues = GetValuesDictionary(routeContext.Values);
if (!langRouteValues.ContainsKey("lang") && ActionContext.HttpContext.Items.ContainsKey("lang"))
langRouteValues.Add("lang", ActionContext.HttpContext.Items["lang"]);
var path = _linkGenerator.GetPathByRouteValues(
ActionContext.HttpContext,
routeContext.RouteName,
langRouteValues,
fragment: routeContext.Fragment == null ? FragmentString.Empty : new FragmentString("#" + routeContext.Fragment));
return GenerateUrl(routeContext.Protocol, routeContext.Host, path);
}
}

In Asp.Net Core, I use the below two methods and it is able to successfully generate the URL.
[Route("{segment}/test", Name = "name"]
var url1 = Url.RouteUrl("name", new { segment = "aa" });
var url2 = Url.Action("Action", "Controller", new { segment = "aa" });

How to get Url without uri paramters in Middleware - AspCore

I was implementing a custom middleware and I was trying to access the request url without the Uri parameters.
All what I have access while implementing a custom middleware is HttpContext
public async Task InvokeAsync(HttpContext context)
The HttpContext has a property Request that has a Path property which could return back the full url with URI parameters.
For example: /api/v1/customer/12345 What I want to get is the route api/v1/customer/{customerId}
Is this something fesiable?

Is this something fesiable?
No,you can't.A route is an ASP.NET Core MVC concept and its existence can therefore only be found within the MVC middleware of ASP.NET Core.
Not sure what is your middleware used to do.As a workaround is that you could did your stuff in Action Filter:
public class LogActionFilter : IActionFilter
{
public void OnActionExecuted(ActionExecutedContext context)
{
}
public void OnActionExecuting(ActionExecutingContext context)
{
//get the request route template
var routeTemplate = context.ActionDescriptor.AttributeRouteInfo.Template;
}
}

Maybe I'm late, but I had to do it in a middleware and did this with following function:
private string GetRoutePath(HttpContext httpContext)
{
string path = httpContext.Request.Path.ToString();
string[] pathValues = path.Split("/");
RouteData route = httpContext.GetRouteData();
// Remove controller and action values from route.
// We are looking to replace parameters only
route.Values.Remove("controller");
route.Values.Remove("action");
foreach (KeyValuePair<string, object?> routeValue in route.Values)
{
for (int i=1; i< pathValues.Length; i++)
{
if (routeValue.Value == null) { continue; }
if (pathValues[i].Equals(routeValue.Value.ToString(), StringComparison.OrdinalIgnoreCase))
{
pathValues[i] = "{" + routeValue.Key + "}";
}
}
}
return string.Join("/", pathValues);
}

Implementing OnActionExecuted on a custom ActionFilter

I'm currently trying to implement request logging for my WebAPI project. We're changing this to be async up and down. Consider the following example from our old action filter:
public class LogRequestActionFilter : ActionFilterAttribute
{
private ILogRepository _logRepository;
private RequestLogEntity _requestLogEntity;
public override void OnActionExecuting(HttpActionContext actionContext)
{
_logRepository = (ILogRepository)GlobalConfiguration.Configuration.DependencyResolver.GetService(typeof(ILogRepository));
_requestLogEntity = new RequestLogEntity
{
LogDate = DateTime.UtcNow,
Success = false
};
_logRepository.Add(_requestLogEntity);
}
public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
{
Exception exception = actionExecutedContext.Exception;
if (exception == null)
{
_requestLogEntity.Success = true;
}
else
{
_requestLogEntity.ErrorMessage = exception.Message;
}
_logRepository.Update(_requestLogEntity);
}
}
I'm trying to get away from using a service locator in my filters, by using passive attributes and filter dispatchers. I've been following this example from Steven (the author of SimpleInjector). This is great for some of my other filters, and it works like a charm, I've managed to use this article to make a passive authorisation attribute/filter for example.
But now it's apparent that using this I lose the ability to capture the request when it is finished, ie. OnActionExecuted.

How to Post/Get and not wait for the response (Async like Ajax) in asp net

I'm working with c# mvc 5 and I have a url which writes a log.
I call it in ajax in all my pages via javascript:
$.ajax({ url: log?page=index&userid=15, async: true });
Now I'm willing to log more critical data, so, for safety matters I need to remove this javascript from my pages, and instead, put it in every controller and every action of my projects.
There is a way to do this asyn in asp net mvc 5?
What I want is something like this:
public ActionResult Index()
{
// I want a method that makes a post/get to some url, but don't block
// the rest of the code. I don't need any return from the post
// It would be nice to be a Post, but a Get would do the trick
PostOrGetAsync("log?page=index&userid=15");
return view();
}
Thank you in advance!

There is a way to do this async in asp net mvc 5? What I want is something like this:
Yes. However, your url in ajax log?page=index&userid=15 does not appear to be a remote server so you can call it directly.
public async ActionResult Index()
{
// I want a method that makes a post/get to some url, but don't block
// the rest of the code. I don't need any return from the post
// It would be nice to be a Post, but a Get would do the trick
var controller = new LogController();
await controller.Log("index", 15);
return view();
}
This really isn't maintainable. To make it global requires a little bit of work. You can use an ActionFilter to globally log all calls.
public class LogActionFilterAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
Log("OnActionExecuting", filterContext.RouteData);
}
public override void OnActionExecuted(ActionExecutedContext filterContext)
{
Log("OnActionExecuted", filterContext.RouteData);
}
public override void OnResultExecuting(ResultExecutingContext filterContext)
{
Log("OnResultExecuting", filterContext.RouteData);
}
public override void OnResultExecuted(ResultExecutedContext filterContext)
{
Log("OnResultExecuted", filterContext.RouteData);
}
private void Log(string methodName, RouteData routeData)
{
var controllerName = routeData.Values["controller"];
var actionName = routeData.Values["action"];
var message = String.Format("{0} controller:{1} action:{2}",
methodName,
controllerName,
actionName);
Debug.WriteLine(message, "Action Filter Log");
}
}
You can either apply the Log to specific actions/controllers:
[LogActionFilter()]
public ActionResult Index()
{
return view();
}
or all controllers:
protected void Application_Start()
{
// Register global filter
GlobalFilters.Filters.Add(new MyActionFilterAttribute());
RegisterGlobalFilters(GlobalFilters.Filters);
}
However, asp.net-mvc does not currently support async action filters, but I don't think you need it anyway.
I need some information that is inside the method. Like, when the user is creating a new registry.
[LogActionFilter()]
public ActionResult Index()
{
SomeSharedLogic();
return view();
}
Extension Method
public static ControllerExtensions()
{
public static void SomeSharedLogic(this ControllerBase controller)
{
controller.TempData["ShareLogicValue"] = "WhateveR";
}
}
Update the log method
public override void OnActionExecuted(ActionExecutedContext filterContext)
{
var sharedLogic = filterContext.Controller.TempData["ShareLogicValue"]
as String;
var logName = "OnActionExecuted";
if (sharedLogic != null)
{
logName += ":" + sharedLogic;
}
Log(logName, filterContext.RouteData);
}

Need to log asp.net webapi 2 request and response body to a database

I am using Microsoft Asp.net WebApi2 hosted on IIS. I very simply would like to log the request body (XML or JSON) and the response body for each post.
There is nothing special about this project or the controller processing the post. I am not interested in using logging frameworks like nLog, elmah, log4net, or the built-in tracing features of web API unless it is necessary to do so.
I am simply wanting to know where to put my logging code and how to get the actual JSON or XML from the incoming and outgoing request and response.
My controller post method:
public HttpResponseMessage Post([FromBody])Employee employee)
{
if (ModelState.IsValid)
{
// insert employee into to the database
}
}

I would recommend using a DelegatingHandler. Then you will not need to worry about any logging code in your controllers.
public class LogRequestAndResponseHandler : DelegatingHandler
{
protected override async Task<HttpResponseMessage> SendAsync(
HttpRequestMessage request, CancellationToken cancellationToken)
{
if (request.Content != null)
{
// log request body
string requestBody = await request.Content.ReadAsStringAsync();
Trace.WriteLine(requestBody);
}
// let other handlers process the request
var result = await base.SendAsync(request, cancellationToken);
if (result.Content != null)
{
// once response body is ready, log it
var responseBody = await result.Content.ReadAsStringAsync();
Trace.WriteLine(responseBody);
}
return result;
}
}
Just replace Trace.WriteLine with your logging code and register the handler in WebApiConfig like this:
config.MessageHandlers.Add(new LogRequestAndResponseHandler());
Here is the full Microsoft documentation for Message Handlers.

There are multiple approaches to generically handle Request/Response logging for every WebAPI method calls:
ActionFilterAttribute:
One can write custom ActionFilterAttribute and decorate the controller/action methods to enable logging.
Con: You need to decorate every controller/methods (still you can do it on base controller, but still it doesn't address cross cutting concerns.
Override BaseController and handle logging there.
Con: We are expecting/forcing the controllers to inherit from a custom base controller.
Using DelegatingHandler.
Advantage: We are not touching controller/method here with this approach. Delegating handler sits in isolation and gracefully handles the request/response logging.
For more indepth article, refer this http://weblogs.asp.net/fredriknormen/log-message-request-and-response-in-asp-net-webapi.

One of the option you have is using creating a action filter and decorating your WebApiController/ApiMethod with it.
Filter Attribute
public class MyFilterAttribute : System.Web.Http.Filters.ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
if (actionContext.Request.Method == HttpMethod.Post)
{
var postData = actionContext.ActionArguments;
//do logging here
}
}
}
WebApi controller
[MyFilterAttribute]
public class ValuesController : ApiController{..}
or
[MyFilterAttribute]
public void Post([FromBody]string value){..}
Hope this helps.

Getting access to request message is easy. Your base class, ApiController contains .Request property, which, as name suggests, contains the request in parsed form. You simply examine it for whatever you're looking to log and pass it to your logging facility, whichever it may be. This code you can put in the beginning of your action, if you need to do it for just one or a handful.
If you need to do it on all actions (all meaning more than a manageable handful), then what you can do is override .ExecuteAsync method to capture every action call for your controller.
public override Task<HttpResponseMessage> ExecuteAsync(
HttpControllerContext controllerContext,
CancellationToken cancellationToken
)
{
// Do logging here using controllerContext.Request
return base.ExecuteAsync(controllerContext, cancellationToken);
}

This seems to be a pretty old thread but worh sharing another solution.
You can add this method in your global.asax file which will be triggered every after HTTP request ends.
void Application_EndRequest(Object Sender, EventArgs e)
{
var request = (Sender as HttpApplication).Request;
var response = (Sender as HttpApplication).Response;
if (request.HttpMethod == "POST" || request.HttpMethod == "PUT")
{
byte[] bytes = request.BinaryRead(request.TotalBytes);
string body = Encoding.UTF7.GetString(bytes);
if (!String.IsNullOrEmpty(body))
{
// Do your logic here (Save in DB, Log in IIS etc.)
}
}
}

This is really old topic but I spent much time(search the internet) to do these thing so I will just post my solution here.
Concept
Override ExecuteAsync of APicontroller method for tracking Inbound request,in my solution I create Base_ApiController as a parent of my project's API controllers .
Use System.Web.Http.Filters.ActionFilterAttribute to track Outbound response of api controller
***(Additional)***Use System.Web.Http.Filters.ExceptionFilterAttribute to log when exception occure.
1. MyController.cs
[APIExceptionFilter] // use 3.
[APIActionFilter] // use 2.
public class Base_APIController : ApiController
{
public bool IsLogInbound
{
get
{ return ConfigurationManager.AppSettings["LogInboundRequest"] =="Y"? true:false ; }
}
/// <summary>
/// for logging exception
/// </summary>
/// <param name="controllerContext"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public override Task<HttpResponseMessage> ExecuteAsync(
HttpControllerContext controllerContext,
CancellationToken cancellationToken
)
{
// Do logging here using controllerContext.Request
// I don't know why calling the code below make content not null Kanit P.
var content = controllerContext.Request.Content.ReadAsStringAsync().Result.ToString(); // keep request json content
// Do your own logging!
if (IsLogInbound)
{
try
{
ErrLog.Insert(ErrLog.type.InboundRequest, controllerContext.Request,
controllerContext.Request.RequestUri.AbsoluteUri
, content);
}
catch (Exception e) { }
}
// will not log err when go to wrong controller's action (error here but not go to APIExceptionFilter)
var t = base.ExecuteAsync(controllerContext, cancellationToken);
if (!t.Result.IsSuccessStatusCode)
{
}
return t;
}
2. APIActionFilter.cs
public class APIActionFilter : System.Web.Http.Filters.ActionFilterAttribute
{
public bool LogOutboundRequest
{
get
{ return ConfigurationManager.AppSettings["LogInboundRequest"] == "Y" ? true : false; }
}
public override void OnActionExecuted(HttpActionExecutedContext actionExecutedContext)
{
try {
var returndata = actionExecutedContext.Response.Content.ReadAsStringAsync().Result.ToString();
//keep Json response content
// Do your own logging!
if (LogOutboundRequest)
{
ErrLog.Insert(ErrLog.type.OutboundResponse, actionExecutedContext.Response.Headers,
actionExecutedContext.ActionContext.ControllerContext.ControllerDescriptor.ControllerName
+ "/"
+ actionExecutedContext.ActionContext.ActionDescriptor.ActionName
, returndata );
}
} catch (Exception e) {
}
}
}
}
3. APIExceptionFilter.cs
public class APIExceptionFilter : ExceptionFilterAttribute
{
public bool IsLogErr
{
get
{ return ConfigurationManager.AppSettings["LogExceptionRequest"] == "Y" ? true : false; }
}
public override void OnException(HttpActionExecutedContext context)
{
try
{
//Do your own logging!
if (IsLogErr)
{
ErrLog.Insert(ErrLog.type.APIFilterException, context.Request,
context.ActionContext.ControllerContext.ControllerDescriptor.ControllerName
+ "/"
+ context.ActionContext.ActionDescriptor.ActionName
, context.Exception.ToString() + context.Exception.StackTrace);
}
}catch(Exception e){
}
if (context.Exception is NotImplementedException)
{
context.Response = new HttpResponseMessage(HttpStatusCode.NotImplemented);
}
else {
context.Response = new HttpResponseMessage(HttpStatusCode.InternalServerError);
}
}
}