I wanted to create a custom route configuration that looks something like this:
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{location}/{id}",
defaults: new { id = RouteParameter.Optional }
I need to have a location attribute which will contain an integer id denoting the location of a specific API user.
After that, I will be putting a custom attribute at the controller level, something like:
[VerifyLocation]
public class SomeController : ApiController
which does some background validation for the location value passed to every endpoint. This means I need to be able to get the integer value of the location attribute.
I am aware that you could use the Route attribute to customize your routes, but the thing is want to do this without having to put in a [Route("api/{location:id}/{id:int"}] on all my end points.
How do I go about doing this?
(In case someone stumbles upon this question)
One approach is through an ActionFilterAttribute:
public class VerifyLocation : ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
var routeData = actionContext.RequestContext.RouteData;
var location = routeData.Values["location"];
// Do your thing here
base.OnActionExecuting(actionContext);
}
}
Related
I have WebApi controllers that end with the "Api" suffix in their names (For ex: StudentsApiController, InstructorsApiController). I do this to easily differentiate my MVC controllers from WebApi controllers. I want my WebApi routes to look similar to
http://localhost:50009/api/students/5 and not http://localhost:50009/api/studentsapi/5.
Currently to achieve this, I am setting up routes like
routes.MapHttpRoute(
name: "GetStudents",
routeTemplate: "api/students/{id}",
defaults: new { controller = "StudentsApi", id = RouteParameter.Optional });
routes.MapHttpRoute(
name: "GetInstructors",
routeTemplate: "api/instructors/{id}",
defaults: new { controller = "InstructorsApi", id = RouteParameter.Optional });
This is turning out to be very cumbersome as I have to add a route for each method in my controllers. I am hoping there should be an easy way to setup route templates that automatically adds the "api" suffix the controller name while processing routes.
Following #Youssef Moussaoui's direction I ended up writing the following code that solved the problem.
public class ApiControllerSelector : DefaultHttpControllerSelector
{
public ApiControllerSelector(HttpConfiguration configuration)
: base(configuration)
{
}
public override string GetControllerName(HttpRequestMessage request)
{
if (request == null)
throw new ArgumentNullException("request");
IHttpRouteData routeData = request.GetRouteData();
if (routeData == null)
return null;
// Look up controller in route data
object controllerName;
routeData.Values.TryGetValue("controller", out controllerName);
if (controllerName != null)
controllerName += "api";
return (string)controllerName;
}
}
And register it in Global.asax as
GlobalConfiguration.Configuration.Services.Replace(typeof(IHttpControllerSelector),
new ApiControllerSelector(GlobalConfiguration.Configuration));
Now that ASP.NET Web API 2 is out, there is a much less cumbersome way to do more complex routing like that you suggested, by using attribute routing.
At the top of your controller just add the following attribute:
[RoutePrefix("api/students")]
public class StudentsApiController : ApiController
{
...
}
And then before each API method:
[Route("{id}"]
public HttpResponseMessage Get(int id)
{
...
}
There is a bit of setup required, but the positives of doing routing this way are many. For one, you can put the routing with the controllers and methods that do the actual work, so you're never searching around wondering if you have the right route. Secondly and more importantly, it's much easier to do more complex routing, like having the controller name different from the route name (like you want) or having very complex patterns to match against.
I think the extensibility point you're looking for is the controller selector. You can create a class that derives from DefaultHttpControllerSelector and overrides the GetControllerName to strip out the "api" part. You can then register this controller selector on your service's configuration Services.
Following Youssef's comment on muruug's answer would look something like this
public class ApiControllerSelector : DefaultHttpControllerSelector
{
public ApiControllerSelector (HttpConfiguration configuration) : base(configuration) { }
public override string GetControllerName(HttpRequestMessage request)
{
return base.GetControllerName(request) + "api";
}
}
I have a web project with two models - IndicatorModel and GranteeModel. I also have corresponding ApiControllers for each - IndicatorsController, and GranteesController. I'm planning on using this setup for a data API alongside my actual web project, so I've created a new Area in my project named simply "Api". In my ApiAreaRegistration class, I'm registering routes for these controllers like this:
context.Routes.MapHttpRoute(
name: "ApiDefault",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
Basically, a request to http://myapp/api/indicators/123 should go to the Indicators controller, and it should specifically be handled by an action method that accepts an integer parameter. My controller class is setup as follows, and it works perfectly:
public class IndicatorsController : ApiController
{
// get: /api/indicators/{id}
public IndicatorModel Get(int id)
{
Indicator indicator = ...// find indicator by id
if (indicator == null)
{
throw new HttpResponseException(HttpStatusCode.NotFound);
}
return new IndicatorModel(indicator);
}
}
My GranteesController class is setup identically:
public class GranteesController : ApiController
{
// get: /api/grantees/{id}
public GranteeModel Get(int granteeId)
{
Grantee grantee = ... // find grantee by Id
if (grantee == null)
{
throw new HttpResponseException(HttpStatusCode.NotFound);
}
return new GranteeModel(grantee);
}
}
Now the problem - if I try a request to http://myapp/api/grantees/123, I get a 404 and I'm 100% positive that the 404 is not coming from my Get method. For one, I've tried debugging and logging within that method, and the method is never actually hit. Also, the actual output (json) to the request looks like this:
{
"Message": "No HTTP resource was found that matches the request URI 'http://myapp/api/grantees/25'.",
"MessageDetail": "No action was found on the controller 'Grantees' that matches the request."
}
Also, the output to my TraceWriter log looks like this:
;;http://myapp/api/grantees/10
DefaultHttpControllerSelector;SelectController;Route='controller:grantees,id:10'
DefaultHttpControllerSelector;SelectController;Grantees
HttpControllerDescriptor;CreateController;
DefaultHttpControllerActivator;Create;
DefaultHttpControllerActivator;Create;MyApp.Areas.Api.Controllers.GranteesController
HttpControllerDescriptor;CreateController;MyApp.Areas.Api.Controllers.GranteesController
GranteesController;ExecuteAsync;
ApiControllerActionSelector;SelectAction;
DefaultContentNegotiator;Negotiate;Type='HttpError', formatters=[JsonMediaTypeFormatterTracer...
So my request is getting routed correctly - the correct controller is selected, and the Id property is set correctly (10). However, the ApiControllerActionSelector isn't finding a method on the controller which matches. I've also tried adding in the [HttpGet] attribute to my Get methods, with no success.
Does anyone have any ideas of what might be happening here? I cannot for the life of me figure out why the action selector isn't finding the correct action.
The parameter name on GranteesController's action need to be modified from 'granteeId' to 'id':
public GranteeModel Get(int id)
As it is not, I have a site where you must come in on a single url and a cookie is set to track which customer you are affiliated with. I want to change this so that certain controllers only use a url like this:
/{friendlyName}/{controller}/{index}/{id}
that friendly name is unique and lets me select the correct customer without using the cookie kludge.
I have controllers: Home, Redirect that I do not want the friendly name part of (and possibly more).
I have a few others that fit this category that I would like to move into their own areas. How can I not include the areas as valid friendly names? For instance, I have a controller that services up content in an iframe called Framed. currently, a url for this looks like /Framed/action/id. I could put this in an area called Framed with a controller the same name as the action, and I should still be able to maintain the same url.
For the controller Error I want the friendly name to be optional
I have other controllers that I want the friendly name to be required: SignIn, SignOut, Account
Once I have the routing, the problem is altering the code so that my redirects maintain the friendlyurl. Any ideas on how to do that?
My problem is just coming up with a good plan of attack on how to change the routing of my site. I must maintain backwards compatibility of some of the urls - namely anything I don't want the friendly url part of, including the controllers I discussed slitting into their own areas. I'm looking for any good suggests on how to lay this out and go about altering the changes.
To accomplish your objectives, you will need a combination of routes and RouteConstraints. Also, you will need to enforce rules that a friendlyName is unique, and is different from the names of any controllers or areas.
The following routes should be sufficient in RegisterRoutes() in Global.asax.cs:
routes.MapRoute(
"WithFriendlyName",
"{friendlyName}/{controller}/{index}/{id}",
new { controller = "Home", action = "Index", id = UrlParameter.Optional },
new { friendlyName = new MustBeFriendlyName() }
);
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/{id}", // URL with parameters
new { controller = "Home", action = "Index", id = UrlParameter.Optional },
new { controller = new MustNotRequireFriendlyName() }
);
The RouteConstraints should look something like this:
using System;
using System.Web;
using System.Web.Routing;
namespace Examples.Extensions
{
public class MustBeFriendlyName : IRouteConstraint
{
public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
{
// return true if this is a valid friendlyName
// MUST BE CERTAIN friendlyName DOES NOT MATCH ANY
// CONTROLLER NAMES OR AREA NAMES
var _db = new DbContext();
return _db.FriendlyNames.FirstOrDefault(x => x.FriendlyName.ToLowerInvariant() ==
values[parameterName].ToString().ToLowerInvariant()) != null;
}
}
public class MustNotRequireFriendlyName : IRouteConstraint
{
private const string controllersRequiringFriendlyNames =
"SignIn~SignOut~Account";
public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
{
// return true if this controller does NOT require a friendlyName
return controllersRequiringFriendlyNames.ToLowerInvariant()
.Contains(values[parameterName].ToString().ToLowerInvariant());
}
}
}
This should get you started.
As far as the URLs generated by your redirects, if the routing is set up correctly, the URL generation should follow, so that the only changes you are likely to need are those to insure {friendlyName} is being passed.
You probably will have to add some additional routes and constraints as you get further into your changes.
Just wanted to add to this, as the optional prefix been biting me for the past couple of days. While I want to use the solution provided by #counsellorben, I also needed to be able to address the routes by the same name, which is impossible when using 2 routes.
It took me some headscratching, but finally the solution actually seemed very simple. I just needed to create an intermediate aggregate route:
public class AggregateRoute : RouteBase
{
private readonly RouteBase[] _routes;
public AggregateRoute(params RouteBase[] routes)
{
_routes = routes;
}
public override RouteData GetRouteData(HttpContextBase httpContext)
{
RouteData routeData = null;
foreach (var route in _routes)
{
routeData = route.GetRouteData(httpContext);
if (routeData != null) break;
}
return routeData;
}
public override VirtualPathData GetVirtualPath(RequestContext requestContext, RouteValueDictionary values)
{
VirtualPathData virtualPath = null;
foreach (var route in _routes)
{
virtualPath = route.GetVirtualPath(requestContext, values);
if (virtualPath != null) break;
}
return virtualPath;
}
}
This allows me to do:
routes.Add(
"RouteName",
new AggregateRoute(
new Route("{path}", new MvcRouteHandler()),
new Route("{prefix}/{path}", new MvcRouteHandler())
)
);
Which enables resolving either route by the same name, which is impossible when adding both routes separately:
Url.RouteLink("RouteName", new RouteValueDictionary{
new{path="some-path"}});
Url.RouteLink("RouteName", new RouteValueDictionary{
new{path="some-prefix/some-path"}});
I use the default route definition:
{controller}/{action}/{id}
where id = UrlParameter.Optional. As much as I understand it this means when id is not being part of the URL this route value will not exists in the RouteValues dictionary.
So this also seems perfectly possible (both GET):
public ActionResult Index() { ... } // handle URLs: controller/action
public ActionResult Index(int id) { ... } // handle URLs: controller/action/id
When id is missing the first action would be executed, but when id is present, the second one would execute. Fine, but it doesn't work. It can't resolve actions.
How can I accomplish this?
I'm thinking of writing a custom action method selector attribute like:
[RequiresRouteValue(string valueName)]
This would make it possible to use this kind of action methods. But is this the only way of doing it?
Is there something built-in I can hang on to?
Use either:
[HttpGet]
public ActionResult Index() { ... } // handle URLs: controller/action
[HttpPost]
public ActionResult Index(int id) { ... } // handle URLs: controller/action/id
Or just have one with a nullable param:
public ActionResult Index(int? id) { ... } // handles both instances
EDIT:
Would something like this work?
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/", // URL with parameters
new { controller = "Login", action = "Index" } // Parameter defaults
);
routes.MapRoute(
"DefaultWithValue", // Route name
"{controller}/{action}/{id}", // URL with parameters
new { controller = "Login", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);
Well from the exception that action can't be determines is pretty clear that actions are resolved first then data binder comes into play and examines action's parameters and tries to data bind values to them. Makes perfect sense.
This makes perfect sense. There would be no point in first trying to data bind values to all possible types and see what we get and then look for an appropriate action. That would be next to impossible.
So. Since action selection is the problem here I guess the best (and only) way to solve this (if I don't want to use a multifaceted single action method) is to write a custom action method selector attribute.
You can read all the details and get the code on my blog:
Improving Asp.net MVC maintainability and RESTful conformance
This is more like a conceptual question. When to use Model Binding (in ASP.NET MVC Framework) and when to inject objects using IoC (lets say Autofac here) ?
One specific scenario is like lets say, I have the following action method
public ActionResult EditProfile(string UserId)
{
// get user object from repository using the the UserId
// edit profile
// save changes
// return feedback
}
In the above scenario, is it possible to inject a user object to action method such that it automatically gets the user object using the UserId ? The resulting signature being:
public ActionResult EditProfile(UserProfile userObj) //userObj injected *somehow* to automatically retreive the object from repo using UserId ?
Sorry if it all doesn't makes sense. It`s my first time using IoC.
EDIT:
This is the way to do it > http://buildstarted.com/2010/09/12/custom-model-binders-in-mvc-3-with-imodelbinder/
You can do what you need using a custom action filter. By overriding OnActionExecuting, we have access to the route data, and the action parameters of the action that will be executed. Given:
public class BindUserProfileAttribute : ActionFilterAttribute
{
public override OnActionExecuting(FilterContext filterContext)
{
string id = (string)filterContext.RouteData.Values["UserId"];
var model = new UserProfile { Id = id };
filtextContext.ActionParameters["userObj"] = model;
}
}
This attribute allows us to create the parameters that will be passed into the action, so we can load the user object at this point.
[BindUserProfile]
public ActionResult EditProfile(UserProfile userObj)
{
}
You'll probably need to get specific with your routes:
routes.MapRoute(
"EditProfile",
"Account/EditProfile/{UserId}",
new { controller = "Account", action = "EditProfile" });
In MVC3 we get access to the new IDepedencyResolver interface, which allows us to perform IoC/SL using whatever IoC container or service locator we want, so we can push a service like a IUserProfileFactory into your filter, to then be able to create your UserProfile instance.
Hope that helps?
Model binding is used for your data. Dependency injection is used for your business logic.