In VBScript via CSCRIPT only, no web involved: how to handle a WinHTTP object's events?

[jjasmith4]

I've written a small VBS script to GET or POST an URL to a WinHTTP object and put its plain-text output to stdout -- any body text it needs should be send via stdin. Please note that it's a stand-alone VBS file, so there's no web involved whatsoever -- it's simply invoked with CSCRIPT SENDURL.VBS GET/POST <url> at a Command Prompt -- SENDURL.VBS is my script.

The problem is that if it times out, that causes an error, and the WinHTTP object's properties such as ResponseText all become invalid, so I want to have a wrapper class which captures the WInHTTP object's OnError event and handles it more gracefully. I have an XLSM which does all this with a wrapper class handling the events, and it works great, but I can't get the class I make in SENDURL.VBS to react to any events. How is this done?

I've Googled this for days, and all I see is stuff about some function called GetRef, which gets a pointer to a function, so I would do something like objWinHTTP.OnError = GetRef(<myErrorHandler>), but this only works in the context of a web page, not via the Command Prompt and CSCRIPT. I also read about WScript.ConnectObject, but that doesn't work either.

Here's the complete class. How can I get event handlers to work when the events happen? Many thanks!

class clsWebRequestor

    public mWinHTTPrequest        ' the WinHTTP object
    public BegStatus            ' Status at start
    public BegContentType        ' Content type at start
    public ErrNumber            ' Error number on error
    public ErrDescription        ' Error description on error
    public Started, Finished

    ''' CLASS EVENTS

    Private Sub Class_Initialize()
        
        Set mWinHTTPrequest = WScript.CreateObject("WinHttp.WinHttpRequest.5.1", "mWinHTTPrequest_")

        WScript.ConnectObject mWinHTTPrequest, "mWinHTTPrequest_"

        mWinHTTPrequest.SetAutoLogonPolicy AutoLogonPolicy_Always
        mWinHTTPrequest.SetTimeouts 300000,300000,300000,300000    ' 300ms = 5 minutes

        BegStatus = 0            ' These really just establish data type
        BegContentType = ""

        ErrNumber = 0
        ErrDescription = ""

        Started = False
        Finished = False

        with mWinHTTPrequest    ' Set up member event handlers
            set .OnError            = mWinHTTPrequest_OnError
            set .OnResponseStart    = mWinHTTPrequest_OnResponseStart
            set .OnResponseFinished = mWinHTTPrequest_OnResponseFinished
        end with

    End Sub

    Private Sub Class_Terminate()
        if not (mWinHTTPrequest is nothing) then mWinHTTPrequest.Abort
        Set mWinHTTPrequest = Nothing
    End Sub

    ''' WINHTTP EVENTS

    Private Sub mWinHTTPrequest_OnResponseStart(ByVal Status, ByVal ContentType) ' long and string
        BegStatus = Status
        BegContentType = ContentType
        
        ErrNumber = 0
        ErrDescription = ""
        
        Started = True
        Finished = False

    End Sub

    Private Sub mWinHTTPrequest_OnError(ByVal ErrorNumber, ByVal ErrorDescription) ' long and string
        ErrNumber = ErrorNumber
        ErrDescription = ErrorDescription
        Started = False
        Finished = True
    End Sub

    Private Sub mWinHTTPrequest_OnResponseFinished()
        Started = False
        Finished = True
    End Sub

End Class