Generate links for routes with non-parameter url segments on ASP.NET MVC 2

Question

Hi everyone,

I have a route defined with several hardcoded (non-parameter) segments:

routes.MapRoute(null, "suggestion/list/by/{tag}", 
       new { controller = "Suggestion", action = "List", tag = UrlParameter.Optional });

Suppose I'm in the Index view of SuggestionController, which has a Suggestion object for Model, how can I create a link that matches that route?

I know I can accomplish I by using plain ol' html like:

<a href="/suggestion/list/by/<%=Model.Tag %>"><%=Model.Tag %></a>

But this makes it impossible to pass on other route parameters (as a RouteValueDictionary, for instance), doesn't it?

I was actually wondering whether is would be possible to do using one of the provided helpers, but without naming the route. I'd prefer to keep the route name as null in order to avoid hard-coding to much on my views, but I can't figure out how to user these non-parameter segments in Html.ActionLink or RouteLink methods.

Any ideas?

Thanks in advance.

Answer 1

The helper methods will take into account routes that you set up so you will be able to use them and they will output the URLs as you want. For example:

<%= Html.Action(Model.Tag, "List", "Suggestion", new { tag = Model.Tag }, null) %>

Or even better, if you are using the MVC futures assembly you will be able to do away with the magic strings and do:

<%= Html.Action<SuggestionController>(c => c.List(Model.Tag), Model.Tag) %> // Add checks for null if Tag can be null

EDIT: As Pointed out in the comments, there is a typo above, the calls to Action, should be ActionLink

Answer 2

I believe that it is best to use RouteLink method in this case. Using RouteLink you can explicitly define the name of the route you want to use. So if you dont have any other reason not to put a name in the route, name it like "suggestion" (or anything else you want). So the RouteLink will be:

<%: Html.RouteLink(Model.Tag, "suggestion", new RouteValueDictionary { tag = Model.Tag })

I had a similar problem with a complex route, and this was the only solution i have found. Hope it helps...