/mcs/class/System.Web.Mvc2/System.Web.Mvc/HandleErrorAttribute.cs

/* ****************************************************************************

 *

 * Copyright (c) Microsoft Corporation. All rights reserved.

 *

 * This software is subject to the Microsoft Public License (Ms-PL). 

 * A copy of the license can be found in the license.htm file included 

 * in this distribution.

 *

 * You must not remove this notice, or any other, from this software.

 *

 * ***************************************************************************/



namespace System.Web.Mvc {

    using System;

    using System.Diagnostics.CodeAnalysis;

    using System.Globalization;

    using System.Web;

    using System.Web.Mvc.Resources;



    [SuppressMessage("Microsoft.Performance", "CA1813:AvoidUnsealedAttributes",

        Justification = "This attribute is AllowMultiple = true and users might want to override behavior.")]

    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = true)]

    public class HandleErrorAttribute : FilterAttribute, IExceptionFilter {



        private const string _defaultView = "Error";



        private readonly object _typeId = new object();



        private Type _exceptionType = typeof(Exception);

        private string _master;

        private string _view;



        public Type ExceptionType {

            get {

                return _exceptionType;

            }

            set {

                if (value == null) {

                    throw new ArgumentNullException("value");

                }

                if (!typeof(Exception).IsAssignableFrom(value)) {

                    throw new ArgumentException(String.Format(CultureInfo.CurrentUICulture,

                        MvcResources.ExceptionViewAttribute_NonExceptionType, value.FullName));

                }



                _exceptionType = value;

            }

        }



        public string Master {

            get {

                return _master ?? String.Empty;

            }

            set {

                _master = value;

            }

        }



        public override object TypeId {

            get {

                return _typeId;

            }

        }



        public string View {

            get {

                return (!String.IsNullOrEmpty(_view)) ? _view : _defaultView;

            }

            set {

                _view = value;

            }

        }



        public virtual void OnException(ExceptionContext filterContext) {

            if (filterContext == null) {

                throw new ArgumentNullException("filterContext");

            }

            if (filterContext.IsChildAction) {

                return;

            }



            // If custom errors are disabled, we need to let the normal ASP.NET exception handler

            // execute so that the user can see useful debugging information.

            if (filterContext.ExceptionHandled || !filterContext.HttpContext.IsCustomErrorEnabled) {

                return;

            }



            Exception exception = filterContext.Exception;



            // If this is not an HTTP 500 (for example, if somebody throws an HTTP 404 from an action method),

            // ignore it.

            if (new HttpException(null, exception).GetHttpCode() != 500) {

                return;

            }



            if (!ExceptionType.IsInstanceOfType(exception)) {

                return;

            }



            string controllerName = (string)filterContext.RouteData.Values["controller"];

            string actionName = (string)filterContext.RouteData.Values["action"];

            HandleErrorInfo model = new HandleErrorInfo(filterContext.Exception, controllerName, actionName);

            filterContext.Result = new ViewResult {

                ViewName = View,

                MasterName = Master,

                ViewData = new ViewDataDictionary<HandleErrorInfo>(model),

                TempData = filterContext.Controller.TempData

            };

            filterContext.ExceptionHandled = true;

            filterContext.HttpContext.Response.Clear();

            filterContext.HttpContext.Response.StatusCode = 500;



            // Certain versions of IIS will sometimes use their own error page when

            // they detect a server error. Setting this property indicates that we

            // want it to try to render ASP.NET MVC's error page instead.

            filterContext.HttpContext.Response.TrySkipIisCustomErrors = true;

        }

    }

}