Professional ASP.NET MVC 4

Extending Controllers

Controller actions are the glue that pulls together your application; they talk to models via data access layers, make rudimentary decisions about how to achieve activities on behalf of the user, and decide how to respond (with views, JSON, XML, and so on). Customizing how actions are selected and executed is an important part of the MVC extensibility story.

Selecting Actions

ASP.NET MVC enables influencing how actions are selected for execution through two mechanisms: choosing action names and selecting (filtering) action methods.

Choosing Action Names with Name Selectors

Renaming an action is handled by attributes that derive from ActionNameSelectorAttribute. The most common use of action name selection is through the [ActionName] attribute that ships with the MVC framework. This attribute allows the user to specify an alternative name and attach it directly to the action method itself. Developers who need a more dynamic name mapping can implement their own custom attribute derived from ActionNameSelectorAttribute.

Implementing ActionNameSelectorAttribute is a simple task: implement the IsValidName abstract method, and return true or false as to whether the requested name is valid. Because the action name selector is allowed to vote on whether or not a name is valid, the decision can be delayed until you know what name the request is asking for. For example, say you wanted to have a single action that handled any request for an action name that began with ...