T4MVC

Introduction#

T4MVC is a T4 template that generates strongly-typed helpers for use in MVC Routing mechanisms, as opposed to magic strings. T4MVC will detect the various controllers, actions, and views, and create references to those views, making compile-time errors in the event that an attempt to Route or access a View is invalid.

Calling an Action

In MVC, there are some scenerios where you want to specify an action for routing purposes, either for a link, form action, or a redirect to action. You can specify an action via the MVC namespace.

When given a Controller, such as HomeController:

public class HomeController : Controller
{
    public ActionResult Index()
    {
        ...
    }
    public ActionResult MyAction()
    {
        ...
    }
    public ActionResult MyActionWithParameter(int parameter)
    {
        ...
    }
}

T4MVC will generate an inherited controller that overrides the action. This override will set the route data properly so that MVC’s UrlHelper will generate the proper Url. You can call this method and pass it into the various methods for UrlHelper. The examples below assume the default MVC route is being used:

Link

To generate an a tag with the specified text:

@Html.ActionLink("Link Text", MVC.Home.Index() )
//result: <a href="/">Link Text</a>
@Html.ActionLink("Link Text", MVC.Home.MyAction() )
//result: <a href="/Home/MyAction">Link Text</a>
//T4MVC also allows you to specify the parameter without creating an anonymous object:
@Html.ActionLink("Link Text", MVC.Home.MyActionWithParameter(1) )
//result: <a href="/Home/MyActionWithParameter/1">Link Text</a>

To generate a url:

@Url.Action( MVC.Home.Index() )
//result: /
@Url.Action("Link Text", MVC.Home.MyAction() )
//result: /Home/MyAction
@Url.Action("Link Text", MVC.Home.MyActionWithParameter(1) )
//result: /Home/MyActionWithParameter/1

Notice that T4MVC follows the same rules as MVC Routing - it won’t specify default route variables, so that the Index action on the HomeController doesn’t generate /Home/Index but instead the perfectly valid and abbreviated form of /.

Form Method

To generate a form tag with the correct action specified:

@Html.BeginForm( MVC.Home.Index(), FormMethod.Get /* or FormMethod.Post */ )
{
    //my form
}
//result:
<form action="/" method="GET">
    //my form
</form>
@Html.BeginForm( MVC.Home.MyActionWithParameter(1), FormMethod.Get /* or FormMethod.Post */ )
{
    //my form
}
//result:
<form action="/Home/MyActionWithParameter/1" method="GET">
    //my form
</form>

Redirect To Action

When in a controller, you may want to redirect to an action from the current action. This can be done, likeso:

public class RedirectingController : Controller
{
    public ActionResult MyRedirectAction()
    {
        ...
        return RedirectToAction( MVC.Redirecting.ActionToRedirectTo() );
        //redirects the user to the action below.
    }
    public ActionResult ActionToRedirectTo()
    {
        ...
    }
}