Routes and optional nullable parameters

[RobertVejvoda]

My route is defined as:

dotvvmConfiguration.RouteTable.Add("Test, "Test/{parentId}/{childId?}", "Views/test.dothtml");

The childId is an optional parameter.

Method call to route.BuildUrl(new {parentId, childId} throws exception.

The issue is likely in DotvvmRoute.cs, method ParseParameter()

if (v.TryGetValue(name, out obj))
    return prefix + obj.ToString();
return "";

--> obj is null

The workaround is not to set parameters having null values at all, but it's not ideal.

var url = childId.HasValue ? route.BuildUrl(new {parentId, childId}) : route.BuildUrl(new { parentId });