AppConfiguration

Legusol · February 24th, 2011, 06:33 PM

I am having a problem with the AppConfiguration as referenced in Chapter 19.

I added the following to the AppConfiguration.vb file:

Code:

Public Shared ReadOnly Property FromAddress() As String
    Get
      Dim result As String = WebConfigurationManager.AppSettings.Get("FromAddress")
      If Not String.IsNullOrEmpty(result) Then
                Throw New Exception("AppSetting FromAddress not found in web.config file.")
      End If
      Throw New Exception("AppSetting FromAddress not found in web.config file.")
    End Get
  End Property

It states that by doing this an error would be thrown if FromAddress is not found in the web.config file.

I tried running the app without adding a key to the web.config. The problem is that the site runs normal and no error is thrown. Did I forget a step someplace. I have gone back and forth through this chapter and can't seem to find what I may have missed.

I also took the Final code from the download and removed the FromAddress from its web.config and ran the site and again it ran fine.

Any thoughts?

Thanks!

Imar · February 25th, 2011, 02:11 PM

Hi there,

Take a look at this:

Quote:

If Not String.IsNullOrEmpty(result) Then

Notice the Not that shouldn't be there? This causes the error to occur when the value is *not* empty, while it should be the other way around.

Cheers,

Imar

Legusol · February 25th, 2011, 03:53 PM

Hi Imar,

I pasted the wrong code. I was testing to see if I could get the error to throw in either case. The actual code I am using is which as far as I can see if straight from the book on page 702:

Code:

 Public Shared ReadOnly Property ACHEmail() As String
        Get
            Dim result As String = WebConfigurationManager.AppSettings.Get("ACHEmail")
            If Not String.IsNullOrEmpty(result) Then
                Return result
            End If
            Throw New Exception("AppSetting ACHEmail not found in the web.config file.")
        End Get
    End Property

If I am reading this right is should be that if the key ACHEmail does not exist or is empty then throw the error. I tried removing my ACHEmail key as well as renaming it to ACHEmail1 as well as setting ACHEmail to "".

Any thoughts here. As I said in my previous post, I even ran the code from the book for Chapter 19 and the Final and removed one of the keys (specifically the FromAddress) from the web.config and I didn't get the error there either.

I do remember when I was working through the book that I got the error when testing this but now that I am creating a website I can't get it to work

Thanks for your response!

Imar · February 25th, 2011, 05:11 PM

You won't get the error on startup, but only when you try to access this property. Is that the case?

Imar

Legusol · April 14th, 2011, 11:37 AM

Hi Imar,

Sorry for the delay in my response. I have been very busy with things at work. That was the problem. I wasn't actively requesting the config item. I guess I thought that on startup the AppConfiguration would be checked.

Thanks again!

Imar · April 15th, 2011, 03:05 AM

Hi there,

Quote:

I guess I thought that on startup the AppConfiguration would be checked.

Nope, as you found out, the AppConfiguration code only executes when your own code calls it.

You could call them (ignoring their return values) in the start up event in Global.asax:

Code:

  Sub Application_Start(ByVal sender As Object, ByVal e As EventArgs)
    ' Code that runs on application startup
   Dim notUsed As String = AppConfiguration.ACHEmail
  notUsed As String = AppConfiguration.SomeOtherProperty
  End Sub

This calls your properties at the start of the application, resulting in a very early exception in case something is missing.

Hope this helps,

Imar