Question

Here is my scenario. For the example lets say that I need to return a list of cars based on a search criteria. I would like to have a single View to display the results since the output will be the same, but I need several ways of getting there. For instance, I may have a Form with a textbox to search by year. I may have another separate page that contains a hyperlink for all red, Toyota cars. How do I handle these multiple scenarios in the same View and Controller. My dilemma is that the search could contain several options… year, make, model, etc but I don’t know where to put them.

What is the best approach for this? Should I define the parameters in the routing or go with query strings, etc?

Answer 1

Option 1

Of course you always can choose the way of /car/search/?vendor=Toyota&color=Red&model=Corola and I think it will be good for you.

routes.MapRoute(     'CarSearch',     'car/search',     new { controller = 'car', action = 'search' } ); 

You can get params from Request.Params in action in this case.

Option 2

Or you can define params in the routing table, but AFAIK it will be required to make a set of rules for all possible combinations, because an order of the params matter, for example:

        routes.MapRoute(             'CarSearch1',             'car/search/vendor/{vendor}/color/{color}/model/{model}',             new {controller = 'car', action = 'search'}         );          routes.MapRoute(             'CarSearch2',             'car/search/color/{color}/vendor/{vendor}/model/{model}',             new {controller = 'car', action = 'search'}         );          routes.MapRoute(             'CarSearch3',             'car/search/model/{model}/color/{color}/vendor/{vendor}',             new {controller = 'car', action = 'search'}         ); 

… an so on. It’s true if you are going with the standard MvcRouteHandler.

But it was an easy ways 🙂

Option 3

The hard, but, I think, most elegant way, is to make your own IRouteHandler implementation – it will give you much more flexibility in params order. But again, its a hard way, dont go with it if you have a simple app. So, just for example of how to make it this way (very simple example):

Add new route to the list of routes:

routes.Add     (         new Route             (                 'car/search/{*data}',                 new RouteValueDictionary(new {controller = 'car', action = 'search', data = ''}),                 new MyRouteHandler()             )     ); 

Add classes that will tweak the standard request processing chain:

class MyRouteHandler : IRouteHandler {     public IHttpHandler GetHttpHandler(RequestContext requestContext)     {         return new MyHttpHandler(requestContext);     } }  class MyHttpHandler : MvcHandler {     public MyHttpHandler(RequestContext requestContext) : base(requestContext)     {     }      protected override void ProcessRequest(HttpContextBase httpContext)     {         IController controller = new CarController();         (controller as Controller).ActionInvoker = new MyActionInvoker();         controller.Execute(RequestContext);     } }  class MyActionInvoker : ControllerActionInvoker {     protected override ActionResult InvokeActionMethod(MethodInfo methodInfo, IDictionary<string, object> parameters)     {         // if form of model/{model}/color/{color}/vendor/{vendor}         var data = ControllerContext.RouteData.GetRequiredString('data');         var tokens = data.Split('/');          var searchParams = new Dictionary<string, string>();         for (var i = 0; i < tokens.Length; i++)         {             searchParams.Add(tokens[i], tokens[++i]);         }          parameters['searchParams'] = searchParams;          return base.InvokeActionMethod(methodInfo, parameters);     } } 

In controller:

public ActionResult Search(IDictionary<string, string> searchParams) {     ViewData.Add         (             // output 'model = Corola, color = red, vendor = Toyota'             'SearchParams',             string.Join(', ', searchParams.Select(pair => pair.Key + ' = ' + pair.Value).ToArray())         );     return View(); } 

And it will work with any search parameters order:

/car/search/vendor/Toyota/color/red/model/Corola /car/search/color/red/model/Corola/vendor/Toyota /car/search/model/Corola/color/red/vendor/Toyota 

But also dont forget to make a link generation logic, because Html.ActionLink and Html.RenderLink will not give you url in pretty form of /car/search/model/Corola/color/red/vendor/Toyota, so you’ll need to make a custom link generator.

So, if you need a really flexible routing – you’d better go with this hard way 🙂