Managing web.config appSettings

Question

I wanted a pattern to manage web.config appsettings. I want to be able to have a default setting if the config setting was missing. I also wanted the check for the value in the config file to happen only once, not each time the the value is retrieved.

Public NotInheritable Class ExternalReportRequestBL
 ''' <summary>
 ''' The default value for max number of request attempts
 ''' </summary>
 ''' <remarks></remarks>
 Private Shared _ReportRequestMaxExecuteAttemptDefault As Integer
 Shared Sub New()
 If Not Integer.TryParse(ConfigurationManager.AppSettings("ReportRequestMaxExecuteAttempt"), ExternalReportRequestBL._ReportRequestMaxExecuteAttemptDefault) Then
 _ReportRequestMaxExecuteAttemptDefault = 10
 End If
 End Sub
 Friend Shared ReadOnly Property MaxNumberOfTries As Integer
 Get
 Return ExternalReportRequestBL._ReportRequestMaxExecuteAttemptDefault
 End Get
 End Property
End Class

Now, I can access the variable from anywhere in the assembly:

ExternalReportRequestBL.MaxNumberOfTries

What are your thoughts?

• RubberDuck: May I ask what lend you to wanting this? Typically, those settings are specifically for specifying defaults and configuration settings. I'm smelling an XY problem, but I don't yet understand what your real problem is.

Answer 1

Integer.TryParse will overwrite the value of that shared property with 0 if the value is not there. Use something like this instead:

Shared Sub New()
 Dim parsed As Integer
 If Integer.TryParse(ConfigurationManager.AppSettings("ReportRequestMaxExecuteAttempt"), parsed) Then
 _ReportRequestMaxExecuteAttemptDefault = parsed
 End If
End Sub

• Shai Cohen: You are correct. Changed my question accordingly.