Script Component As Source: The Collection Of Variables Locked For Read Access Is Not Available At This Point.

Hello, I am trying to configure a Script Component as a data source. Although this should be a simple exercise, I am running into a problem.

My control flow contains a Foreach Loop with a file iterator. The Directory Expression of the Foreach Loop Editor is supplied by an expression mapped to a package level variable called inputdirectory. The FileNameRetrieval Expression is mapped to a package scoped variable called filename.

My data flow is encapsulated by the Foreach Loop, and contains a Script Component as Source for the Data Flow Source, and a Flat File for the Data Flow Destination. The contents of the Script Designer are as follows:




Code Block
Imports System
Imports System.Data
Imports System.Math
Imports Microsoft.SqlServer.Dts.Pipeline.Wrapper
Imports Microsoft.SqlServer.Dts.Runtime.Wrapper
Imports System.IO
Public Class ScriptMain

Inherits UserComponent
Dim thisFileDate As Date
Dim thisFileName As String
Dim thisFilePath As String
Public Overrides Sub CreateNewOutputRows()

thisFileName = ReadOnlyVariables("filename").Value.ToString()
thisFilePath = ReadOnlyVariables("inputdirectory").Value.ToString()
thisFileDate = File.GetCreationTime(thisFilePath & "" & thisFileName)
FileSpecBuffer.AddRow()
FileSpecBuffer.FileName = thisFileName
FileSpecBuffer.FullPath = thisFilePath & "" & thisFileName
FileSpecBuffer.CreateDate = thisFileDate
End Sub
End Class






When I debug the package, I get the following error:

The collection of variables locked for read access is not available at this point.

at Microsoft.SqlServer.Dts.Pipeline.ScriptComponent.get_ReadOnlyVariables()

at ScriptComponent_67311120e6eb4162a3ea1f70847f04de.ScriptMain.CreateNewOutputRows()

at ScriptComponent_67311120e6eb4162a3ea1f70847f04de.UserComponent.PrimeOutput(Int32 Outputs, Int32[] OutputIDs, PipelineBuffer[] Buffers)

at Microsoft.SqlServer.Dts.Pipeline.ScriptComponentHost.PrimeOutput(Int32 outputs, Int32[] outputIDs, PipelineBuffer[] buffers)

My googlefu fails me at reconciling this. I have read various posts about changing the line ReadOnlyVariables("filename").Value to ReadWriteVariables("filename").Value, and handling the buffer assignment in PostExecute. The problem is that all examples shown are either for Script Component as Destination or Script Component as Transformation. I have tried playing with the Custom Properties in the Script Commponent set the ReadOnlyVariables and ReadWriteVariables, using a PreExecute method, a PostExecute method, all with different errors returning. I'm at a loss here. Could anybody provide me with a simple working example so that I can correctly populate my output buffer in the context of Script Component as Source?


I fully understand that I could just run a Script Task Using System.IO.Directory, and System.IO.File, but I really want to make this package work in the manner I've described. Any help would be appreciated.

Thanks,

John T