MSDN Magazine - March 2008 - (Page 44)

comments about how hard it is to test Web Forms page classes? Well, controllers are a lot easier to test. To follow along, you’ll need to install Visual StuIn fact, a controller can be instantiated directly, and dio 2008 and get a copy of the MVC Framework. action methods called, without any additional inAt the time of this writing, it’s available as part of frastructure. You don’t need an HTTP context, and the December 2007 Community Technology Preyou don’t need a server, just a test harness. As an exview (CTP) of the ASP.NET Extensions (asp.net/ ample, I’ve included a Visual Studio Team System downloads/3.5-extensions). You’ll want to grab both the (VSTS) unit test for this class in Figure 3. extensions CTP and the MVC Toolkit, which inThere are several things going on here. The actual cludes some very useful helper objects. Once you test is very straightforward: instantiate the controller, download and install the CTP, you’ll get a new projcall the method with the expected data, then verify ect type in your New Project dialog called ASP.NET that the correct view was rendered. I do the check by MVC Web Application. creating a Test-specific subclass that overrides the Selecting the MVC Web Application project gives RenderView method. This allows me to short-ciryou a solution that looks a little bit different from the cuit the actual creation of HTML. I just care that the usual Web site or application. The solution template right data was sent to the view and that the correct creates a Web application with some new directories view was rendered. I don’t care about the underly(as shown in Figure 2). In particular, the Controling details of the view itself for this test. lers directory contains the controller classes, and the Views directory (and all of its subdirectories) Figure 2 The MVC Project Creating a View contains the views. Structure Of course, ultimately it is necessary for me to I’m going to write a very simple controller that returns a name passed in on the URL. Right-clicking on the Con- generate some HTML, so let’s create that HiThere view. To do this, trollers folder and choosing Add Item displays the usual Add New first I create a new folder in the solution named Hello under the Item dialog, with some new additions, including an MVC Controller Views folder. By default, the controller will look for a view in the Class and several MVC View components. In this case, I’m adding Views\ folder (the controller prefix is the name of the controller class minus the word “Controller”). So for views an ever-so-imaginatively named HelloController class: using System; rendered by the HelloController, it looks in Views\Hello. The sousing System.Web; lution ends up looking like Figure 4. using System.Web.Mvc; namespace HelloFromMVC.Controllers { public class HelloController : Controller { [ControllerAction] public void Index() { } } } Creating a Controller Figure 3 Controller Unit Test namespace HelloFromMVC.Tests { [TestClass] public class HelloControllerFixture { [TestMethod] public void HiThereShouldRenderCorrectView() { TestableHelloController controller = new TestableHelloController(); controller.HiThere(“Chris”); Assert.AreEqual(“Chris”, controller.Name); Assert.AreEqual(“HiThere”, controller.ViewName); A controller class is a lot lighter weight than a page. As a matter of fact, the only things that are truly necessary are to derive from System.Web.Mvc.Controller and to put the [ControllerAction] attribute on your action methods. An action is a method that’s called in response to a request to a particular URL. Actions are responsible for doing whatever processing is required and then rendering a view. I’ll start by writing a simple action that passes the name along to the view, as you can see here: [ControllerAction] public void HiThere(string id) { ViewData[“Name”] = id; RenderView(“HiThere”); } } } class TestableHelloController : HelloController { public string Name; public string ViewName; protected override void RenderView( string viewName, string master, object data) { this.ViewName = viewName; this.Name = (string)ViewData[“Name”]; } The action method receives the name from the URL via the id parameter (more about how in a moment), stores it in the ViewData collection, and then renders a view named HiThere. Before discussing how this method gets called, or what the view looks like, I’d like to talk about testability. Remember my previous 44 msdnmagazine ASP.NET MVC } } http://asp.net/downloads/3.5-extensions http://asp.net/downloads/3.5-extensions

Table of Contents Feed for the Digital Edition of MSDN Magazine - March 2008

MSDN Magazine - March 2008 Contents Toolbox CLR Inside Out Data Points Advanced Basics Office Space Introducing ASP.NET MVC Loosen Up CI Server Performance Office Development Test Run Security Briefs Extreme ASP.NET Foundations .NET Matters {End Bracket}

MSDN Magazine - March 2008

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