Question

I’m developing a search that have a dynamic number of checkboxes and a price range. I need a route that maps something like this:

/Filter/Attributes/Attribute1, Attribute2, Attribute3/Price/1000-2000

Is this a good way to do that? How can I do that route?

Answer 1

routes.MapRoute(
    "FilterRoute",
    "filter/attributes/{attributes}/price/{pricerange}",
    new { controller = "Filter", action = "Index" }
);

and in your Index action:

public class FilterController: Controller
{
    public ActionResult Index(FilterViewModel model)
    {
        ...
    }
}

where FilterViewModel:

public class FilterViewModel
{
    public string Attributes { get; set; }
    public string PriceRange { get; set; }
}

and if you wanted your FilterViewModel to look like this:

public class FilterViewModel
{
    public string[] Attributes { get; set; }
    public decimal? StartPrice { get; set; }
    public decimal? EndPrice { get; set; }
}

you could write a custom model binder for this view model which will parse the various route tokens.

Ping me if you need an example.

---

UPDATE:

As requested here’s a sample model binder that could be used to parse the route values to the corresponding view model properties:

public class FilterViewModelBinder : IModelBinder
{
    public object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        var model = new FilterViewModel();
        var attributes = bindingContext.ValueProvider.GetValue("attributes");
        var priceRange = bindingContext.ValueProvider.GetValue("pricerange");

        if (attributes != null && !string.IsNullOrEmpty(attributes.AttemptedValue))
        {
            model.Attributes = (attributes.AttemptedValue).Split(new [] { ',' }, StringSplitOptions.RemoveEmptyEntries);
        }

        if (priceRange != null && !string.IsNullOrEmpty(priceRange.AttemptedValue))
        {
            var tokens = priceRange.AttemptedValue.Split('-');
            if (tokens.Length > 0)
            {
                model.StartPrice = GetPrice(tokens[0], bindingContext);
            }
            if (tokens.Length > 1)
            {
                model.EndPrice = GetPrice(tokens[1], bindingContext);
            }
        }

        return model;
    }

    private decimal? GetPrice(string value, ModelBindingContext bindingContext)
    {
        if (string.IsNullOrEmpty(value))
        {
            return null;
        }

        decimal price;
        if (decimal.TryParse(value, out price))
        {
            return price;
        }

        bindingContext.ModelState.AddModelError("pricerange", string.Format("{0} is an invalid price", value));
        return null;
    }
}

which would be registered in Application_Start in Global.asax:

ModelBinders.Binders.Add(typeof(FilterViewModel), new FilterViewModelBinder());