/// <summary>
/// Adds a new outbound route to the <see cref="TreeRouter"/>.
/// </summary>
/// <param name="handler">The <see cref="IRouter"/> for handling the link generation.</param>
/// <param name="routeTemplate">The <see cref="RouteTemplate"/> of the route.</param>
/// <param name="requiredLinkValues">The <see cref="RouteValueDictionary"/> containing the route values.</param>
/// <param name="routeName">The route name.</param>
/// <param name="order">The route order.</param>
/// <returns>The <see cref="OutboundRouteEntry"/>.</returns>
public OutboundRouteEntry MapOutbound(
IRouter handler,
RouteTemplate routeTemplate,
RouteValueDictionary requiredLinkValues,
string routeName,
int order)
{
if (handler == null)
{
throw new ArgumentNullException(nameof(handler));
}
if (routeTemplate == null)
{
throw new ArgumentNullException(nameof(routeTemplate));
}
if (requiredLinkValues == null)
{
throw new ArgumentNullException(nameof(requiredLinkValues));
}
var entry = new OutboundRouteEntry()
{
Handler = handler,
Order = order,
Precedence = RoutePrecedence.ComputeOutbound(routeTemplate),
RequiredLinkValues = requiredLinkValues,
RouteName = routeName,
RouteTemplate = routeTemplate,
};
var constraintBuilder = new RouteConstraintBuilder(_constraintResolver, routeTemplate.TemplateText);
foreach (var parameter in routeTemplate.Parameters)
{
if (parameter.InlineConstraints != null)
{
if (parameter.IsOptional)
{
constraintBuilder.SetOptional(parameter.Name);
}
foreach (var constraint in parameter.InlineConstraints)
{
constraintBuilder.AddResolvedConstraint(parameter.Name, constraint.Constraint);
}
}
}
entry.Constraints = constraintBuilder.Build();
entry.Defaults = new RouteValueDictionary();
foreach (var parameter in entry.RouteTemplate.Parameters)
{
if (parameter.DefaultValue != null)
{
entry.Defaults.Add(parameter.Name, parameter.DefaultValue);
}
}
OutboundEntries.Add(entry);
return(entry);
}
private VirtualPathData GenerateVirtualPath(
VirtualPathContext context,
OutboundRouteEntry entry,
TemplateBinder binder)
{
// In attribute the context includes the values that are used to select this entry - typically
// these will be the standard 'action', 'controller' and maybe 'area' tokens. However, we don't
// want to pass these to the link generation code, or else they will end up as query parameters.
//
// So, we need to exclude from here any values that are 'required link values', but aren't
// parameters in the template.
//
// Ex:
// template: api/Products/{action}
// required values: { id = "5", action = "Buy", Controller = "CoolProducts" }
//
// result: { id = "5", action = "Buy" }
var inputValues = new RouteValueDictionary();
foreach (var kvp in context.Values)
{
if (entry.RequiredLinkValues.ContainsKey(kvp.Key))
{
var parameter = entry.RouteTemplate.GetParameter(kvp.Key);
if (parameter == null)
{
continue;
}
}
inputValues.Add(kvp.Key, kvp.Value);
}
var bindingResult = binder.GetValues(context.AmbientValues, inputValues);
if (bindingResult == null)
{
// A required parameter in the template didn't get a value.
return(null);
}
var matched = RouteConstraintMatcher.Match(
entry.Constraints,
bindingResult.CombinedValues,
context.HttpContext,
this,
RouteDirection.UrlGeneration,
_constraintLogger);
if (!matched)
{
// A constraint rejected this link.
return(null);
}
var pathData = entry.Handler.GetVirtualPath(context);
if (pathData != null)
{
// If path is non-null then the target router short-circuited, we don't expect this
// in typical MVC scenarios.
return(pathData);
}
var path = binder.BindValues(bindingResult.AcceptedValues);
if (path == null)
{
return(null);
}
return(new VirtualPathData(this, path));
}