Binaryworld - GetWebConfigCustomKeyValue - Return and cache a custom key's value fro ... [ ASP.net -> General ]

' Return the value of the specified custom key, stored in the Web.Config file.
' If the value has been already requested before, the function returns its
' cached value.
' The second optional parameter is the path of the Web.Config file where this
' custom key is stored, and it is necessary to add a dependency to that file,
' so that the cached value is discarded if the file is edited.
'
' Example: Dim connString = GetWebConfigCustomKeyValue("ConnString")

Function GetWebConfigCustomKeyValue(ByVal key As String, _
  Optional ByVal webConfigUrl As String = "/Web.Config") As String
  ' if this is not the first time this value is needed,
  ' we can find it in the cache
  Dim value As String = CType(HttpContext.Current.Cache(key), String)

  ' if the retrieved string is empty, the value is not present into the cache,
  ' thus it is retrieved it from Web.Config, and then cached
  If value Is Nothing OrElse value = "" Then
    value = ConfigurationSettings.AppSettings(key)
    HttpContext.Current.Cache.Insert(key, value, _
      New Caching.CacheDependency(webConfigUrl))
  End If

  Return value
End Function