Is it possible to get the route/virtual url associated with a controller action or on a view? I saw that Preview 4 added LinkBuilder.BuildUrlFromExpression helper, but it's not very useful if you want to use it on the master, since the controller type can be different. Any thoughts are appreciated.
You can get that data from ViewContext.RouteData. Below are some examples for how to access (and use) that information:
/// These are added to my viewmasterpage, viewpage, and viewusercontrol base classes:
public bool IsController(string controller)
{
if (ViewContext.RouteData.Values["controller"] != null)
{
return ViewContext.RouteData.Values["controller"].ToString().Equals(controller, StringComparison.OrdinalIgnoreCase);
}
return false;
}
public bool IsAction(string action)
{
if (ViewContext.RouteData.Values["action"] != null)
{
return ViewContext.RouteData.Values["action"].ToString().Equals(action, StringComparison.OrdinalIgnoreCase);
}
return false;
}
public bool IsAction(string action, string controller)
{
return IsController(controller) && IsAction(action);
}
/// Some extension methods that I added to the UrlHelper class.
public static class UrlHelperExtensions
{
/// <summary>
/// Determines if the current view equals the specified action
/// </summary>
/// <typeparam name="TController">The type of the controller.</typeparam>
/// <param name="helper">Url Helper</param>
/// <param name="action">The action to check.</param>
/// <returns>
/// <c>true</c> if the specified action is the current view; otherwise, <c>false</c>.
/// </returns>
public static bool IsAction<TController>(this UrlHelper helper, LambdaExpression action) where TController : Controller
{
MethodCallExpression call = action.Body as MethodCallExpression;
if (call == null)
{
throw new ArgumentException("Expression must be a method call", "action");
}
return (call.Method.Name.Equals(helper.ViewContext.ViewName, StringComparison.OrdinalIgnoreCase) &&
typeof(TController) == helper.ViewContext.Controller.GetType());
}
/// <summary>
/// Determines if the current view equals the specified action
/// </summary>
/// <param name="helper">Url Helper</param>
/// <param name="actionName">Name of the action.</param>
/// <returns>
/// <c>true</c> if the specified action is the current view; otherwise, <c>false</c>.
/// </returns>
public static bool IsAction(this UrlHelper helper, string actionName)
{
if (String.IsNullOrEmpty(actionName))
{
throw new ArgumentException("Please specify the name of the action", "actionName");
}
string controllerName = helper.ViewContext.RouteData.GetRequiredString("controller");
return IsAction(helper, actionName, controllerName);
}
/// <summary>
/// Determines if the current view equals the specified action
/// </summary>
/// <param name="helper">Url Helper</param>
/// <param name="actionName">Name of the action.</param>
/// <param name="controllerName">Name of the controller.</param>
/// <returns>
/// <c>true</c> if the specified action is the current view; otherwise, <c>false</c>.
/// </returns>
public static bool IsAction(this UrlHelper helper, string actionName, string controllerName)
{
if (String.IsNullOrEmpty(actionName))
{
throw new ArgumentException("Please specify the name of the action", "actionName");
}
if (String.IsNullOrEmpty(controllerName))
{
throw new ArgumentException("Please specify the name of the controller", "controllerName");
}
if (!controllerName.EndsWith("Controller", StringComparison.OrdinalIgnoreCase))
{
controllerName = controllerName + "Controller";
}
bool isOnView = helper.ViewContext.ViewName.SafeEquals(actionName, StringComparison.OrdinalIgnoreCase);
return isOnView && helper.ViewContext.Controller.GetType().Name.Equals(controllerName, StringComparison.OrdinalIgnoreCase);
}
/// <summary>
/// Determines if the current request is on the specified controller
/// </summary>
/// <param name="helper">The helper.</param>
/// <param name="controllerName">Name of the controller.</param>
/// <returns>
/// <c>true</c> if the current view is on the specified controller; otherwise, <c>false</c>.
/// </returns>
public static bool IsController(this UrlHelper helper, string controllerName)
{
if (String.IsNullOrEmpty(controllerName))
{
throw new ArgumentException("Please specify the name of the controller", "controllerName");
}
if (!controllerName.EndsWith("Controller", StringComparison.OrdinalIgnoreCase))
{
controllerName = controllerName + "Controller";
}
return helper.ViewContext.Controller.GetType().Name.Equals(controllerName, StringComparison.OrdinalIgnoreCase);
}
/// <summary>
/// Determines if the current request is on the specified controller
/// </summary>
/// <typeparam name="TController">The type of the controller.</typeparam>
/// <param name="helper">The helper.</param>
/// <returns>
/// <c>true</c> if the current view is on the specified controller; otherwise, <c>false</c>.
/// </returns>
public static bool IsController<TController>(this UrlHelper helper) where TController : Controller
{
return (typeof(TController) == helper.ViewContext.Controller.GetType());
}
}
I always try to implement the simplest solution that meets the project requirements. As Enstein said, "Make things as simple as possible, but not simpler." Try this.
<%: Request.Path %>