Asp – Form input validation options in ASP.NET MVC 1.0+

"Obviously you'll still need to validate your input on the server side for the small percentage of users who disable javascript."

Just an update to this comment. Server-side validation has nothing to do with users that run with JavaScript disabled. Instead, it is needed for security reasons, and to do complex validation that can't be done on the client. A form should always have server-side validation. Client-side validation is only there as a convenience.

A malicious user could easily post data to your form bypassing any client-side validation that you have in place. Never trust input data!

From the readme word doc for RC1 (not indexed by google)

ASP.NET Compiler Post-Build Step

Currently, errors within a view file are not detected until run time. To let you detect these errors at compile time, ASP.NET MVC projects now include an MvcBuildViews property, which is disabled by default. To enable this property, open the project file and set the MvcBuildViews property to true, as shown in the following example:

<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <MvcBuildViews>true</MvcBuildViews>
  </PropertyGroup>

Note Enabling this feature adds some overhead to the build time.

You can update projects that were created with previous releases of MVC to include build-time validation of views by performing the following steps:

1. Open the project file in a text editor.
2. Add the following element under the top-most <PropertyGroup> element: <MvcBuildViews>true</MvcBuildViews>
3. At the end of the project file, uncomment the <Target Name="AfterBuild"> element and modify it to match the following:

<Target Name="AfterBuild" Condition="'$(MvcBuildViews)'=='true'">
    <AspNetCompiler VirtualPath="temp" PhysicalPath="$(ProjectDir)\..\$(ProjectName)" />
</Target>