'Copyright (C) 2007 Daniele Iunco

'This program is free software; you can redistribute it and/or modify
'it under the terms of the GNU General Public License as published by
'the Free Software Foundation; either version 2 of the License, or
'(at your option) any later version.

'This program is distributed in the hope that it will be useful,
'but WITHOUT ANY WARRANTY; without even the implied warranty of
'MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
'GNU General Public License for more details.

'You should have received a copy of the GNU General Public License along
'with this program; if not, write to the Free Software Foundation, Inc.,
'51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

Imports System
Imports System.Web

Namespace GiDiNet

    'NotifyErrorHandler v1.0
    'Author: Daniele Iunco
    'Date: 8th May 2007

    'ATTENZIONE: utilizzando questo modulo per qualsiasi file aspx (*.aspx) non sarà possibile utilizzare altri httphandler
    Public Class NotifyErrorHandler
        Inherits UI.PageHandlerFactory
        Implements IHttpHandlerFactory, SessionState.IRequiresSessionState

        'Inserire il percorso della pagina di errore, la pagina deve essere un file .aspx
        Const ErrorPagePath As String = "/errorpage.aspx"

        Public Overrides Function GetHandler(ByVal context As HttpContext, ByVal requestType As String, ByVal virtualPath As String, ByVal path As String) As IHttpHandler
            'Questa parte del modulo praticamente intercetta gli errori in fase di compilazione
            Try
                Dim myHttpHandler As IHttpHandler = MyBase.GetHandler(context, requestType, virtualPath, path)
                Return New myCustomHttpHandler(virtualPath, ErrorPagePath, myHttpHandler)
            Catch ex As Exception
                NotifyErrorToAdmin(ex.Message & vbCrLf & ex.StackTrace)
                Return MyBase.GetHandler(context, requestType, ErrorPagePath, context.Request.MapPath(ErrorPagePath))
            End Try
        End Function

        Public Shared Sub NotifyErrorToAdmin(ByVal ErrorText As String)
            'Modificare le righe seguenti per inserire gli indirizzi e-mail corretti e personalizzare il messaggio di errore
            Dim myMail As New Net.Mail.MailMessage()
            With myMail
                .From = New Net.Mail.MailAddress("from@domain.com") 'Mittente
                .To.Add(New Net.Mail.MailAddress("to@domain.com")) 'Destinatario
                .Subject = "Errore nell'esecuzione della pagina"
                .IsBodyHtml = False
                .Body = "Si è verificato il seguente errore: " & vbCrLf & ErrorText
            End With
            Dim myClient As New Net.Mail.SmtpClient()
            myClient.Send(myMail)
        End Sub

    End Class

    Public Class myCustomHttpHandler
        Implements IHttpHandler, SessionState.IRequiresSessionState
        Private _objHandler As IHttpHandler
        Private _url As String
        Private _errorPage As String

        Public Sub New(ByVal url As String, ByVal errorPage As String, ByVal objHandler As IHttpHandler)
            _objHandler = objHandler
            _url = url
            _errorPage = errorPage
        End Sub

        Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
            Get
                Return _objHandler.IsReusable
            End Get
        End Property

        Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
            'Questa parte del modulo intercetta gli errori generati in fase di esecuzione
            Try
                _objHandler.ProcessRequest(context)
            Catch ex2 As Threading.ThreadAbortException
                'Questa eccezione generalmente è voluta (Uso di Response.Redirect, interruzione del thread da script, etc)
                Exit Sub
            Catch ex As Exception
                NotifyErrorHandler.NotifyErrorToAdmin(TraceException(context, ex))
                Dim _ErrorHandler As IHttpHandler = UI.PageParser.GetCompiledPageInstance(_errorPage, context.Request.MapPath("/errorpage.aspx"), context)
                _ErrorHandler.ProcessRequest(context)
            End Try
        End Sub

        Private Function TraceException(ByRef context As HttpContext, ByVal exOriginal As Exception) As String
            'questa procedura restituisce una stringa contenente delle informazioni sull'eccezione
            'è possibile modificare quanto riportato di seguito per inserire ulteriori dettagli 
            Dim dNow As Date = Now

            Dim sResult As String = "" & _
            "Data/ora: " & dNow.ToShortDateString & " " & dNow.ToLongTimeString & vbCrLf & _
            "" & vbCrLf & _
            "ApplicationPath: " & context.Request.ApplicationPath & vbCrLf & _
            "" & vbCrLf

            If context.Request.QueryString.Count > 0 Then
                sResult &= "URL: " & _url & "?" & context.Request.QueryString.ToString & vbCrLf
            Else
                sResult &= "URL: " & _url & vbCrLf
            End If

            sResult &= "Request path: " & context.Request.Path & vbCrLf & _
               "Remote address: " & context.Request.ServerVariables("REMOTE_ADDR") & vbCrLf & _
               "User: " & "" & vbCrLf & _
               "- Is authenticated: " & context.User.Identity.IsAuthenticated & vbCrLf & _
               "- AuthenticationType: " & context.User.Identity.AuthenticationType & vbCrLf & _
               "- Username: " & context.User.Identity.Name & vbCrLf & _
               "" & vbCrLf & _
               "Message:" & exOriginal.Message & vbCrLf & _
               "Stack Trace:" & exOriginal.StackTrace & vbCrLf

            If Not exOriginal.InnerException Is Nothing Then
                Dim subEx As Exception = exOriginal.InnerException
                sResult &= vbCrLf & _
                "InnerException Message:" & subEx.Message & vbCrLf & _
                "InnerException Stack Trace:" & subEx.StackTrace
            End If

            Return sResult
        End Function
    End Class

End Namespace

<?xml version="1.0"?>
<configuration>
    <system.net>
        <mailSettings>
            <smtp deliveryMethod="Network">
                <network host="indirizzo.mailserver.com" port="25"/>
            </smtp>
        </mailSettings>
    </system.net>

    <system.web>
        <httpHandlers>
            <add verb="GET" path="*.aspx" type="GiDiNet.NotifyErrorHandler"></add>
        </httpHandlers>
    </system.web>
</configuration>