Asp.net-mvc – Specifying read-only session in ASP.NET MVC

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>

Session is used for the TempData store. TempData is a highly limited form of session state which will last only until the next request from a certain user. (Edit In MVC 2+, it lasts until it is next read.) The purpose of TempData is to store data, then do a redirect, and have the stored data be available to the action to which you just redirected.

Using Session for the TempData store means that any distributed caching system which already handles Session will work for TempData. Avoiding using Session directly when TempData will do has a couple of advantages. One is that you don't have to clean up the Session yourself; TempData will "expire" on its own.