URLs with slash in parameter?

Question

Question:

I am creating a wiki software, basically a clone of wikipedia/mediawiki, but in ASP.NET MVC (the MVC is the point, so don't recommend me ScrewTurn).

Now I have a question:

I use this route mapping, to route a URL like:
http://en.wikipedia.org/wiki/ASP.NET

 routes.MapRoute(
 "Wiki", // Routenname
 //"{controller}/{action}/{id}", // URL mit Parametern
 "wiki/{id}", // URL mit Parametern
 new { controller = "Wiki", action = "dbLookup", id = UrlParameter.Optional } // Parameterstandardwerte
 );

Now it just occured to me, that there might be titles like 'AS/400':
http://en.wikipedia.org/wiki/AS/400

Incidentially, there is also this one (title 'Slash'):
http://en.wikipedia.org/wiki//

And this one:
http://en.wikipedia.org/wiki//dev/null

Overall, Wikipedia seems to have a list of interesting titles like this: http://en.wikipedia.org/wiki/Wikipedia:Articles_with_slashes_in_title

How do I make routes like this route correctly ?

Edit:
Something like:
If the URL starts with /Wiki/, and if it doesn't start with /wiki/Edit/ (but not /Wiki/Edit) then pass all the rest of the URL as Id.

Edit:
Hmm, just another problem: How can I route this one:
http://en.wikipedia.org/wiki/C&A

Wikipedia can...

Edit:
According to wikipedia, due to clashes with wikitext syntax, only the following characters can never be used in page titles (nor are they supported by DISPLAYTITLE):

# < > [ ] | { }

http://en.wikipedia.org/wiki/Wikipedia:Naming_conventions_(technical_restrictions)#Forbidden_characters

Edit:
To allow * and &, put

<httpRuntime requestPathInvalidCharacters="" />

into section <system.web> in file web.config

(Found here: http://www.christophercrooker.com/use-any-characters-you-want-in-your-urls-with-aspnet-4-and-iis)

• corlettk: Can you change your routing parameter character to something "more usual", like a question mark, or a comma... something is NOT valid in a title?
• Codo: ASP.NET MVC routing isn't your only problem. Try topics like "LPT", "SQL*plus", "US$", "C#" etc. A lot of them will be caught by IIS. You better think about escaping some of them.

Answer 1

You could use a catchall route to capture everything that follows the wiki part of the url into the id token:

routes.MapRoute(
 "Wiki",
 "wiki/{*id}",
 new { controller = "Wiki", action = "DbLookup", id = UrlParameter.Optional }
);

Now if you have the following request: /wiki/AS/400 it will map to the following action on the Wiki controller:

public ActionResult DbLookup(string id)
{
 // id will equal AS/400 here
 ...
}

As far as /wiki// is concerned I believe you will get a 400 Bad Request error from the web server before this request ever reaches the ASP.NET pipeline. You may checkout the following blog post.

• Stefan Steiger: Nice, that works, but what about when I want to excempt /wiki/Edit/ArticleTitle from this rule ? (but that shouldn't excemp /wiki/Edit)
• Darin Dimitrov: @Quandary, I don't think you could exempt with a catchall rule. You could try defining another route before the one I showed which looks like this wiki/Edit/{*id}.
• Stefan Steiger: @Darin: OK, works perfectly. In Edit, that requires to catch id isnullorempty and redirect to action action dbLookup with id as Edit.
• Stefan Steiger: @Darin: if in the Edit action, I do a if (string.IsNullOrEmpty(id)) return RedirectToAction("dbLookup", "Wiki", new { id = "Edit" }); then I enter a infinite loop... why ?
• Darin Dimitrov: @Quandary, I guess that RedirectToAction("dbLookup", "Wiki", new { id = "Edit" }) resolves to the Edit action once again.

Answer 2

in Attribute Routing in mvc i had the same problem having / in string abc/cde in HttpGet

 [Route("verifytoken/{*token}")]
 [AllowAnonymous]
 [HttpGet]
 public ActionResult VerifyToken(string token)
 {
 //logic here
 }

so you have to place * because after this it will be considered as parameter

• Emil: awesome. this is the best and easiest solution :)
• nixkuroi: This seems to work for one slash, but not two in a row. any ideas there?
• Braden Brown: @Usman What about if you have another route that is [Route("verifytoken/{token}/something")]? Wouldn't the wildcard potentially have conflicts with this route if there are forward slashes? Is there another way to do this for this use case?
• Dimitris Thomas: You are a hero! I was trying to create a custom url with slashes without any luck, no matter what i tried i was getting /Admin/Customers/Edit?id=1 instead of teh desired output /Admin/Customers/Edit/1. That asterisk did the trick! Thanks once again
• pedram: Great answer. it works in HttpMethodAttribute as well. (.net core 3.1) [HttpGet("verifytoken/{*token}")] It works for more than one slash as well. e.g: localhost:44352/api/verifytoken/1234/12/23/rebase.pdf token = "1234/12/23/rebase.pdf"

Answer 3

@Darin: Well, that much is obvious, the question is: Why ? controller + action + id are given, it's like it's passing all these to routing again... – Quandary Jun 13 '11 at 17:38

Quandry - maybe you have already figured this out since your question is over a year old, but when you call RedirectToAction, you are actually sending an HTTP 302 response to the browser, which causes the browser to make a GET request to the specified action. Hence, the infinite loop you are seeing.

See: Controller.RedirectToAction Method

• Stefan Steiger: Server.Transfer resolves this: stackoverflow.com/questions/799511/…

Answer 4

Still as an option write in the file Global.asax:

 var uri = Context.Request.Url.ToString();
 if (UriHasRedundantSlashes(uri))
 {
 var correctUri = RemoveRedundantSlashes(uri);
 Response.RedirectPermanent(correctUri);
 }
 }
 private string RemoveRedundantSlashes(string uri)
 {
 const string http = "http://";
 const string https = "https://";
 string prefix = string.Empty;
 if (uri.Contains(http))
 {
 uri = uri.Replace(http, string.Empty);
 prefix = http;
 }
 else if (uri.Contains(https))
 {
 uri = uri.Replace(https, string.Empty);
 prefix = https;
 }
 while (uri.Contains("//"))
 {
 uri = uri.Replace("//", "/");
 }
 if (!string.IsNullOrEmpty(prefix))
 {
 return prefix + uri;
 }
 return uri;
 }
 private bool UriHasRedundantSlashes(string uri)
 {
 const string http = "http://";
 const string https = "https://";
 if (uri.Contains(http))
 {
 uri = uri.Replace(http, string.Empty);
 }
 else if (uri.Contains(https))
 {
 uri = uri.Replace(https, string.Empty);
 }
 return uri.Contains("//");
 }