How to have a route that goes to 2 destinations - asp.net

Question

I need the ability to have routes like the following URLs.
/authorid
/documentid
/authorid/documentid
I am trying to not to do
/author/1
/document/5
author/1/document/25
How can this be done?
Clarifications.
A document and an author can have the same id. BUT the author should take precedence.
Author: {ID: "djQuery" }
Document: { Aurhor: "Bob", ID: "djQuery" }
Should be accessible via /Bob/djQuery
But if you just go to /djQuery you should get a list of djQuery's documents.

Answer 1

You can achieve what you want with three routes and the appropriate RouteConstraints.
First, you need to establish your Routes:
public static void RegisterRoutes(RouteCollection routes)
{
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.MapRoute(
"Author_Document", // Route name
"{author}/{document}", // URL
new { controller = "ShowDocument", action = "AuthorDocument" }, // Parameters
new { author = new MustBeValidAuthor(), document = new MustBeValidDocument() }
routes.MapRoute(
"Author", // Route name
"{author}", // URL
new { controller = "ShowDocument", action = "Author" }, // Parameters
new { author = new MustBeValidAuthor() }
routes.MapRoute(
"Document", // Route name
"{document}", // URL
new { controller = "ShowDocument", action = "Document" }, // Parameters
new { document = new MustBeValidDocument() }
routes.MapRoute(
"Default", // Route name
"{controller}/{action}/{id}", // URL with parameters
new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);
}
Next, you need to create your RouteConstraints, which must verify that the information provided is valid:
using System;
using System.Web;
using System.Web.Routing;
namespace ExampleApp.Extensions
{
public class MustBeValidAuthor : IRouteConstraint
{
public MustBeValidAuthor() { }
private DbContext _db = new DbContext();
public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
{
return (_db.Authors.Where(u => u.AuthorName == values[parameterName].ToString()).Count() > 0);
}
}
public class MustBeValidDocument : IRouteConstraint
{
public MustBeValidDocument() { }
private DbContext _db = new DbContext();
public bool Match(HttpContextBase httpContext, Route route, string parameterName, RouteValueDictionary values, RouteDirection routeDirection)
{
return (_db.Documents.Where(u => u.DocumentName == values[parameterName].ToString()).Count() > 0);
}
}
}
The RouteConstraints will enfoce the validity of the request, and placing the Routes in this order fulfills your requirements.

Answer 2

I do not think that it is possible to do this just by configuring routes.
The problem is how does the program know if the number that you send is an authorid or a documentid.
What you can do is that /1 goes to a page, on that page you do a check to see if it is a document or an author, then you do a Response.Redirect to the actual page, say /author/1.

Answer 3

Assuming you want
/1
/2
/1/2
I don't think you can achive that beacuse the first two urls will call the same routing rule.
You can't know when to call a method instead of another.
The only solution I can think of, is that if you can discern the ids (for example id from 1 to 10 are authorid while the others are documentId) you can write your custom rulehandler and act accordinlgy calling the right method.
Otherwise you have to put something in the url to make it unique:
"/a1" for authorid and "/d2" for DoumentId would have something like that
routes.MapRoute("", "a{authorId}", new { controller = "Home", action = "AuthorDetail" }, new { authorId = #"\d+" });
routes.MapRoute("", "d{documentId}", new { controller = "Home", action = "DocumentDetail" }, new { documentId = #"\d+" });
EDIT: after your clarification the answer from counsellorben should do what you want

Answer 4

You can use something like this where IsAuthorConstraint has a look up to determine if document or author. Alternatively you can route to a bridging Action and put the logic there, before passing on to document or author action.
context.MapRoute(
"authorid",
"{authorid}",
new { action = "Author", controller = "Controller",
authorid = -1 },
new { authorid = new IsAuthorConstraint() }
);
context.MapRoute(
"document",
"{documentid}",
new { action = "Document", controller = "Controller",
documentid = -1 }
);
// assume overload on author action
context.MapRoute(
"document and author",
"{authorid}/{documentid}",
new { action = "Author", controller = "Controller",
documentid = -1, authorid = -1 }
);
I'm not at a computer so may not be exactly right, but hope you get the idea.

Answer 5

You can only achieve this with Route constraints as #counsellorben suggested but there should be no same id for authorid and documentid.
If there is, a conflict is going to occur there.