rescues.md

Rescues

A rescue is an association of a special view that will only be rendered if an exception happens. The view file must be present in a rescues folder directly under your views folder.

Using Rescues

A rescue can be associated with a controller or per action. You can also bound a rescue with an exception. If the action throws an exception (the action cannot swallow the exception), MonoRail will match the rescue definition that is closely related to the exception type and use the specified view.

To create an association you must use the RescueAttribute. For example:

using Castle.MonoRail.Framework;

[Rescue("dberror", typeof(System.Data.SqlException))]
public class ProductController : Controller
{
    [Rescue("commonerror")]
    public void Index()
    {
        throw new System.Data.SqlException("fake error");
    }

    [Rescue("dumbprogrammer", typeof(DivideByZeroException))]
    public void List()
    {
        int val = 0;
        int x = 10 / val;
    }

    public void Search()
    {
    }
}

The usage of the RescueAttribute in the example above defines the following rules:

• If any action throws a SqlException, the view view/rescues/dberror will be selected
• If the action Index throws any kind of exception (including SqlException), the view view/rescues/commonerror will be selected. This overrides the definition in the controller level.
• If the action List throws a DivideByZeroException, the view view/rescues/dumbprogrammer will be selected.

Whenever an exception happens, the MonoRail context (which is per request) will populate the property LastException so your view can show the exception details.