MVC IgnoreRoute /?_escaped_fragment_= to continue Reverse Proxy with IIS ARR - c#

Technical Information
AngularJS single page app
Umbraco 7.3.0 website, extended to register routes via Umbraco.Core.ApplicationEventHandler in a separate class library
Scenario
I have an AngularJS single page app (SPA) that I'm trying to pre-render via an external PhantomJS service.
I want MVC's route handler to ignore the route /?_escaped_fragment_={fragment}, so the request can be handled directly by ASP.NET and thus passed on to IIS to proxy the request.
In Theory
Umbraco is built on ASP.NET MVC.
Routes are configurable via System.Web.Routing.RouteCollection class.
When extending Umbraco with custom routes, any routes configured via the System.Web.Routing.RouteTable will take precedence over Umbraco routes, thus never being handled by Umbraco**
Possible methods for my scenario
public void Ignore(string url) or
public void Ignore(string url, object constraints)
**I could be wrong. As far as I'm aware, custom routing takes precedence as it's done before the Umbraco routes are registered. However I'm unsure whether telling MVC to ignore a route would also prevent Umbraco from handling that route.
In Practise
I have attempted to ignore the routes with the following:
Attempt one:
routes.Ignore("?_escaped_fragment_={*pathInfo}");
This throws an error: The route URL cannot start with a '/' or '~' character and it cannot contain a '?' character.
Attempt two:
routes.Ignore("{*escapedfragment}", new { escapedfragment = #".*\?_escaped_fragment_=\/(.*)" });
This didn't result in an error, however Umbraco still picked up the request and handed me back my root page. Regex validation on Regexr.
Questions
Can MVC actually ignore a route based on its query string?
Is my knowledge of Umbraco's routing correct?
Is my regex correct?
Or am I missing something?

The built-in routing behavior doesn't take the query string into consideration. However, routing is extensible and can be based on query string if needed.
The simplest solution is to make a custom RouteBase subclass that can detect your query string, and then use the StopRoutingHandler to ensure the route doesn't function.
public class IgnoreQueryStringKeyRoute : RouteBase
{
private readonly string queryStringKey;
public IgnoreQueryStringKeyRoute(string queryStringKey)
{
if (string.IsNullOrWhiteSpace(queryStringKey))
throw new ArgumentNullException("queryStringKey is required");
this.queryStringKey = queryStringKey;
}
public override RouteData GetRouteData(HttpContextBase httpContext)
{
if (httpContext.Request.QueryString.AllKeys.Any(x => x == queryStringKey))
{
return new RouteData(this, new StopRoutingHandler());
}
// Tell MVC this route did not match
return null;
}
public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
{
// Tell MVC this route did not match
return null;
}
}
Usage
public class RouteConfig
{
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
// This route should go first
routes.Add(
name: "IgnoreQuery",
item: new IgnoreQueryStringKeyRoute("_escaped_fragment_"));
// Any other routes should be registered after...
routes.MapRoute(
name: "Default",
url: "{controller}/{action}/{id}",
defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
);
}
}

Related

MVC Conventional and Attribute routing not working together

I am using conventional routing on an ASP.Net MVC project and would like to enable Attribute routing in parallel. I have created the following but I am getting a 404 on the conventional route when enabling attribute routing
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.MapMvcAttributeRoutes();
routes.MapRoute(
name: "Default",
url: "{controller}/{action}/{id}",
defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional }
);
}
Controller
[RoutePrefix("Registration")]
public class RegistrationController : Controller
{
[HttpGet]
[Route("Add/{eventId}")]
public ActionResult Add(int eventId)
{
}
}
Calling
http://localhost/Registration/Add/1
Works, while calling
http://localhost/Registration/Add?eventId=1
No longer works and responds with 404 NotFound
Should work if you make the {eventId} template parameter optional in the route template
[RoutePrefix("Registration")]
public class RegistrationController : Controller {
//GET Registration/Add/1
//GET Registration/Add?eventId=1
[HttpGet]
[Route("Add/{eventId:int?}")]
public ActionResult Add(int eventId) {
//...
}
}
The reason the two were not working is that the route template Add/{eventId} means that the route will only match if the {eventId} is present, which is why
http://localhost/Registration/Add/1
works.
By making it (eventId) optional eventid? it will allow
http://localhost/Registration/Add
to work as the template parameter is not required. This will now allow query string ?eventId=1 to be used, which the routing table will use to match the int eventId parameter argument on the action.
http://localhost/Registration/Add?eventId=1
I also got this issue. Which MVC version are you using?
I faced this issue with MVC in asp.net core.
I think this is a flaw as if you provide Routing attribute on any action method, its conventional route is over ridden and is not longer available so you get 404 error.
For this to work, you can provide another Route attribute to your action method like this. This will work
[Route("Add/{eventId}")]
[Route("Add")]

Restrict route to controller namespace in ASP.NET Core

I'm trying to restrict the controllers of my ASP.NET Core routes to a certain namespace.
In previous versions of ASP.NET MVC there was an overload that provided a string[] namespaces parameter when adding routes. This is missing in ASP.NET MVC 6. So after some googling, I tried playing around with something like
app.UseMvc(routes => {
var dataTokens = new RouteValueDictionary {
{
"Namespaces", new[] {"ProjectA.SomeNamespace.Controllers"}
}
};
routes.MapRoute(
name: "default",
template: "{controller=Home}/{action=Index}/{id?}",
defaults: null,
constraints: null,
dataTokens: dataTokens
);
});
but it doesn't seem to do what I want. Is there a way to restrict the routing engine to a certain namespace?
Update
I just realized it may have to do something with the fact that I'm using attribute routing on each individual controller? Does attribute routing funk up the routes defined by app.UseMvc()?
Update 2
More details:
I've two completely independent Web API projects. Incidentally, a few of the routes are identical in both (ie. ~/api/ping). These projects are independent in Production, one is an endpoint for users, one is an endpoint for administrators.
I also have unit tests, using Microsoft.AspNet.TestHost. A few of these unit tests require functionality of both of these Web API projects (ie. need "admin" endpoint to fully setup a test case for "user"). But when I reference both API projects, the TestHost gets confused because of the identical routes and it complains about "multiple matching routes":
Microsoft.AspNet.Diagnostics.DeveloperExceptionPageMiddleware: Error: An unhandled exception has occurred while executing the request
Microsoft.AspNet.Mvc.Infrastructure.AmbiguousActionException: Multiple actions matched. The following actions matched route data and had all constraints satisfied:
ProjectA.SomeNamespace.Controllers.PingController.Ping
ProjectB.SomeNamespace.Controllers.PingController.Ping
at Microsoft.AspNet.Mvc.Infrastructure.DefaultActionSelector.SelectAsync(RouteContext context)
at Microsoft.AspNet.Mvc.Infrastructure.MvcRouteHandler.<RouteAsync>d__6.MoveNext()
Update:
I've found solution through using ActionConstraint. You have to add custom Action Constraint attribute about duplicate actions.
Example with duplicate Index methods.
First HomeController
namespace WebApplication.Controllers
{
public class HomeController : Controller
{
[NamespaceConstraint]
public IActionResult Index()
{
return View();
}
}
}
Second HomeController
namespace WebApplication
{
public class HomeController : Controller
{
[NamespaceConstraint]
public IActionResult Index()
{
return View();
}
}
}
Configure routing
app.UseMvc(cR =>
cR.MapRoute("default", "{controller}/{action}", null, null,
new { Namespace = "WebApplication.Controllers.HomeController" }));
Action constraint
namespace WebApplication
{
public class NamespaceConstraint : ActionMethodSelectorAttribute
{
public override bool IsValidForRequest(RouteContext routeContext, ActionDescriptor action)
{
var dataTokenNamespace = (string)routeContext.RouteData.DataTokens.FirstOrDefault(dt => dt.Key == "Namespace").Value;
var actionNamespace = ((ControllerActionDescriptor)action).MethodInfo.DeclaringType.FullName;
return dataTokenNamespace == actionNamespace;
}
}
}
First answer:
Does attribute routing funk up the routes defined by app.UseMvc()?
Attribute routing and Convention-based routing (routes.MapRoute(...) work independently. And attribute routes have advantage over convention routes.
but it doesn't seem to do what I want. Is there a way to restrict the routing engine to a certain namespace?
Answer from developers:
Instead of using a list of namespaces to group your controllers we recommend using Areas. You can attribute your controllers (regardless of which assembly they are in) with a specific Area and then create a route for that Area.
You can see a test website that shows an example of using Areas in MVC 6 here: https://github.com/aspnet/Mvc/tree/dev/test/WebSites/RoutingWebSite.
Example using Area with convention-based routing
Controller:
//Reached through /admin/users
//have to be located into: project_root/Areas/Admin/
[Area("Admin")]
public class UsersController : Controller
{
}
Configure convention-based routing:
app.UseMvc(routes =>
{
routes.MapRoute(
"areaRoute",
"{area:exists}/{controller}/{action}",
new { controller = "Home", action = "Index" });
}
Example using Area with attribute-based routing
//Reached through /admin/users
//have to be located into: project_root/Areas/Admin/
[Area("Admin")]
[Route("[area]/[controller]/[action]", Name = "[area]_[controller]_[action]")]
public class UsersController : Controller
{
}

Is it possible for two areas to share the same route and still both be reachable?

I have two areas that register routes as shown below:
"Website" area:
context.MapRoute(
"Landing Controllers",
"{controller}/{action}",
new { controller = "Home", action = "Index" }
);
"Mobile" area:
context.MapRoute(
"Mobile Defaults",
"{controller}/{action}",
new { controller = "MobileHome", action = "Index" },
new { controller = "MobileHome", action = "Index" }
);
By default, one or the other of these routes would be consistently taken when trying to go to the root URL /. But suppose we decorated our controller actions with a custom AuthorizeAttribute, where the OnAuthorization method is overridden to redirect the user to the correct controller when appropriate, as below. (Idea taken from a great blog post.)
public class MobileRedirectAttribute : AuthorizeAttribute
{
public override void OnAuthorization(AuthorizationContext filterContext)
{
var result = // Logic to generate the ActionResult that conditionally
// takes us to the other route goes here.
filterContext.Result = result;
}
}
I've tried using a new RedirectResult and RedirectToRouteResult, neither of which work as I'd like because of the routing conflict. Is there a way to set AuthorizationContext.Result to a value that would take us to the action that we're not currently executing? (As a last resort, I can just prefix the mobile route with some sort of namespacing variable, but I'd like to avoid going down that road just yet.)
My question can probably also be summarized by having a look at Wikipedia's desktop/mobile routing. Their two sites, http://en.m.wikipedia.org/wiki/Main_Page and http://en.wikipedia.org/wiki/Main_Page also share identical routes, but, depending on which mode you're in, return very different results.
Would it be possible to set up Wikipedia's routing in an MVC project where each environment (mobile/desktop) is registered in its own area?
A colleague led me to a promising solution using a custom IRouteConstraint.
public class HelloWorldConstraint : IRouteConstraint
{
public bool Match(HttpContextBase httpContext, Route route,
string parameterName, RouteValueDictionary values,
RouteDirection routeDirection)
{
// Determine whether to accept the route for this request.
var browser = BrowserDetector.Parse(httpContext.Request.UserAgent);
if (browser == BrowserPlatform.Mobile)
{
return true;
}
return false;
}
}
And my route declaration now looks like the below, where the route constraint is attached to a route parameter chosen at random.
context.MapRouteLowercase(
"Mobile Defaults",
"{controller}/{action}",
new { controller = "MobileHome", action = "Index" },
// In this case, it's not so much necessary to attach the constraint to
// a particular route parameter as it is important to be able to inspect
// the HttpContextBase provided by the IRouteConstraint.
new {
controller = new HelloWorldConstraint()
}
);
Not with standard MVC Routing. You can probably do with attribute routing, available in either MVC 5 or via the nuget package, AttributeRouting.

Catch-all route fails to find route with WebApi2 ApiController

I am creating a WebApi2 service, and one of the methods I want to implement represents an HTTP GET from an object within an internal tree structure - so the request would be along the lines of:
GET /values/path/path/to/object/in/tree
So I would want my method to receive "path/to/object/in/tree".
However, I just get a 404 when I run this, and it's interesting that I get a 404 that is different looking to the standard IIS 404. It's titled 'Server Error in '/' Application.', whereas the one for a completely invalid resource is titled 'HTTP Error 404.0 - Not Found'.
I am playing around with the default template to try and see if I can get this to work, hence the similarity.
I have this for my RouteConfig
public static void RegisterRoutes(RouteCollection routes)
{
var route = routes.MapRoute(
name: "CatchAllRoute",
url: "values/path/{*pathValue}",
defaults: new { controller = "Values", action = "GetPath" });
}
And this is my ValuesController:
[System.Web.Mvc.AuthorizeAttribute]
[RoutePrefix("values")]
public class ValuesController : ApiController
{
[Route("test/{value}")]
[HttpGet]
public string Test(string value)
{
return value;
}
[HttpGet]
public string GetPath(string pathValue)
{
return pathValue;
}
}
Interestingly, if I derive from Controller rather than ApiController it works OK, but then the normal attribute routing doesn't work.
I tried following the methodology in this post (http://www.tugberkugurlu.com/archive/asp-net-web-api-catch-all-route-parameter-binding) but I couldn't get it to work.
I'm sure I'm missing something stupidly easy, but having spent a few hours on it I thought it prudent to ask what I'm doing wrong.
Thanks
M
Web api routing is not the same as routing MVC. instead of
route.MapRoute
try
public static void Register(HttpConfiguration config) {
config.MapHttpAttributeRoutes
config.Routes.MapHttpRoute(
name: "CatchAll", routeTemplate: "values/path/{*pathvalue}",
defaults: new {id = RouteParameter.Optional });
}
The reason it works from controller is that MapRoute is the correct format for routing an MVC controller, while MapHttpRoute is designed for API controllers.

ASP.NET MVC Route based on Web Browser/Device (e.g. iPhone)

Is it possible, from within ASP.NET MVC, to route to different controllers or actions based on the accessing device/browser?
I'm thinking of setting up alternative actions and views for some parts of my website in case it is accessed from the iPhone, to optimize display and functionality of it. I don't want to create a completely separate project for the iPhone though as the majority of the site is fine on any device.
Any idea on how to do this?
Mix: Mobile Web Sites with ASP.NET MVC and the Mobile Browser Definition File
Don't know if the above helps as I havn't watched it yet.
And this one;
How Would I Change ASP.NET MVC Views Based on Device Type?
You can create a route constraint class:
public class UserAgentConstraint : IRouteConstraint
{
private readonly string _requiredUserAgent;
public UserAgentConstraint(string agentParam)
{
_requiredUserAgent = agentParam;
}
public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
{
return httpContext.Request.UserAgent != null &&
httpContext.Request.UserAgent.ToLowerInvariant().Contains(_requiredUserAgent);
}
}
And then enforce the constraint to one of the routes like so:
routes.MapRoute(
name: "Default",
url: "{controller}/{action}/{id}",
defaults: new {id = RouteParameter.Optional},
constraints: new {customConstraint = new UserAgentConstraint("Chrome")},
namespaces: new[] {"MyNamespace.MVC"}
);
You could then create another route pointing to a controller with the same name in another namespace with a different or no constraint.
Best bet would be a custom action filter.
All you have to do is inherit from ActionMethodSelectorAttribute, and override the IsValidRequest class.
public class [IphoneRequest] : ActionMethodSelectorAttribute
{
public override bool IsValidForRequest(ControllerContext controllerContext, System.Reflection.MethodInfo methodInfo)
{
// return true/false if device is iphone
Then in your controller
[IphoneRequest]
public ActionResult Index()

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