I have built a class module in Visual basic. One function takes in a variable 
ByRef as a String datatype (strReturn).

The function tests to make sure all other data is properly defined if not, the 
function passes the error back to the client through the strReturn variable.

I made a vb project, set my reference, and tested the class module.(or at this 
point it was a dll) Everything worked. the String variable sent to the class 
module was returning with correct messages.

When I use an asp page, I try to reference the same dll and I get multiple 
errors. I will show you the code, and the error message that was given to me. I 
will start with the class module code.

Here is the Class Code (l_ variables are local, prv are private properties):
Public Function InsertNewStatus(ByRef ReturnString As String, _
                                Optional ByVal l_Description As String, _
                                Optional ByVal l_StatusType As String, _
                                Optional ByVal l_ISActive As Boolean) As Boolean
    On Error Resume Next
    If prvDescription = "" And l_Description = "" Then
        ReturnString = "InsertNewStatus.Description is improperly defined."
        InsertNewStatus = False
        Exit Function
    End If
    If prvStatusType = "" And l_StatusType = "" Then
        ReturnString = "InsertNewStatus.StatusType is improperly defined."
        InsertNewStatus = False
        Exit Function
    End If
End Function

Here is the VB code that works:
    Dim nStatus As OEMaintenance.Status
    Set nStatus = New OEMaintenance.Status
    nStatus.InsertNewStatus strReturn, "PAID", "PAYMENT", True
    MsgBox strReturn
    Set nStatus = Nothing

Here is the ASP (VBScript) code that doesn't work:
Dim nStatus, ret, strReturn
Set nStatus = server.CreateObject("OEMaintenance.Status")
strReturn = "Not working"
nStatus.IsActive = true
nStatus.StatusType = "PAYMENT"
if nStatus.InsertNewStatus(strReturn) then
	Response.Write strReturn
else
	Response.Write strReturn
end if
Set nStatus = Nothing
Here is the error message
Microsoft VBScript runtime error '800a000d' 

Type mismatch: 'InsertNewStatus' 

/Maintain/Statuses.asp, line 13 

I can do this: strReturn = CSTR(strReturn) to make sure the variable is a 
String, instead of variant, and still get the same number. the ByRef String 
variable (strReturn) is required, and is the only one required. Currently I am 
not setting the Description, so I should be getting a message back saying 
Description is not currently defined.

If I do:
If nStatus.InsertNewStatus("hi") it works, but obviously won't send me a 
message.

Is there any reason why I can't send a variable into a dll ByRef using ASP?

TIA-
Mike S.

What if you change the method signature in your function so that it accepts
a variant strReturn, not a string.

There are no strings in ASP. Even if you do CStr() you still have a variant
(of subtype String)

Cheers
Ken

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
From: <jstmehr4u3@a...>
Subject: [asp_web_howto] ByRef Arguments


: I have built a class module in Visual basic. One function takes in a
variable
: ByRef as a String datatype (strReturn).
:
: The function tests to make sure all other data is properly defined if not,
the
: function passes the error back to the client through the strReturn
variable.
:
: I made a vb project, set my reference, and tested the class module.(or at
this
: point it was a dll) Everything worked. the String variable sent to the
class
: module was returning with correct messages.
:
: When I use an asp page, I try to reference the same dll and I get multiple
: errors. I will show you the code, and the error message that was given to
me. I
: will start with the class module code.
:
: Here is the Class Code (l_ variables are local, prv are private
properties):
: Public Function InsertNewStatus(ByRef ReturnString As String, _
:                                 Optional ByVal l_Description As String, _
:                                 Optional ByVal l_StatusType As String, _
:                                 Optional ByVal l_ISActive As Boolean) As
Boolean
:     On Error Resume Next
:     If prvDescription = "" And l_Description = "" Then
:         ReturnString = "InsertNewStatus.Description is improperly
defined."
:         InsertNewStatus = False
:         Exit Function
:     End If
:     If prvStatusType = "" And l_StatusType = "" Then
:         ReturnString = "InsertNewStatus.StatusType is improperly defined."
:         InsertNewStatus = False
:         Exit Function
:     End If
: End Function
:
: Here is the VB code that works:
:     Dim nStatus As OEMaintenance.Status
:     Set nStatus = New OEMaintenance.Status
:     nStatus.InsertNewStatus strReturn, "PAID", "PAYMENT", True
:     MsgBox strReturn
:     Set nStatus = Nothing
:
: Here is the ASP (VBScript) code that doesn't work:
: Dim nStatus, ret, strReturn
: Set nStatus = server.CreateObject("OEMaintenance.Status")
: strReturn = "Not working"
: nStatus.IsActive = true
: nStatus.StatusType = "PAYMENT"
: if nStatus.InsertNewStatus(strReturn) then
: Response.Write strReturn
: else
: Response.Write strReturn
: end if
: Set nStatus = Nothing
: Here is the error message
: Microsoft VBScript runtime error '800a000d'
:
: Type mismatch: 'InsertNewStatus'
:
: /Maintain/Statuses.asp, line 13
:
: I can do this: strReturn = CSTR(strReturn) to make sure the variable is a
: String, instead of variant, and still get the same number. the ByRef
String
: variable (strReturn) is required, and is the only one required. Currently
I am
: not setting the Description, so I should be getting a message back saying
: Description is not currently defined.
:
: If I do:
: If nStatus.InsertNewStatus("hi") it works, but obviously won't send me a
: message.
:
: Is there any reason why I can't send a variable into a dll ByRef using
ASP?
:
: TIA-
: Mike S.

Ok, after much thought / research / coding and recoding I have found that 
solution.

In the DLL change the BYREF argument to accept the datatype VARIANT. (Or by not 
explicitly stating a datatype.) But, the key is that you can't act on that 
variable sent BYREF. (I have www.15seconds.com to thank)

You have to declare a local variable to act on in the DLL, then reassign the 
value to the variable sent BYREF. For instance:

Public function InsertText(byref ReturnMessage, byval Message)
dim TempString as string
TempString = ReturnMessage
if Message = "" then
  TempString = "InsertText.Message is improperly Defined."
else
  TempString = "InsertText Passed."
end if
ReturnMessage = TempString
end function

That works.
Mike - ENJOY!
> What if you change the method signature in your function so that it accepts
> a variant strReturn, not a string.
> 
> There are no strings in ASP. Even if you do CStr() you still have a variant
> (of subtype String)
> 
> Cheers
> Ken
> 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> From: <jstmehr4u3@a...>
> Subject: [asp_web_howto] ByRef Arguments
> 
> 
> : I have built a class module in Visual basic. One function takes in a
> variable
> : ByRef as a String datatype (strReturn).
> :
> : The function tests to make sure all other data is properly defined if not,
> the
> : function passes the error back to the client through the strReturn
> variable.
> :
> : I made a vb project, set my reference, and tested the class module.(or at
> this
> : point it was a dll) Everything worked. the String variable sent to the
> class
> : module was returning with correct messages.
> :
> : When I use an asp page, I try to reference the same dll and I get multiple
> : errors. I will show you the code, and the error message that was given to
> me. I
> : will start with the class module code.
> :
> : Here is the Class Code (l_ variables are local, prv are private
> properties):
> : Public Function InsertNewStatus(ByRef ReturnString As String, _
> :                                 Optional ByVal l_Description As String, _
> :                                 Optional ByVal l_StatusType As String, _
> :                                 Optional ByVal l_ISActive As Boolean) As
> Boolean
> :     On Error Resume Next
> :     If prvDescription = "" And l_Description = "" Then
> :         ReturnString = "InsertNewStatus.Description is improperly
> defined."
> :         InsertNewStatus = False
> :         Exit Function
> :     End If
> :     If prvStatusType = "" And l_StatusType = "" Then
> :         ReturnString = "InsertNewStatus.StatusType is improperly defined."
> :         InsertNewStatus = False
> :         Exit Function
> :     End If
> : End Function
> :
> : Here is the VB code that works:
> :     Dim nStatus As OEMaintenance.Status
> :     Set nStatus = New OEMaintenance.Status
> :     nStatus.InsertNewStatus strReturn, "PAID", "PAYMENT", True
> :     MsgBox strReturn
> :     Set nStatus = Nothing
> :
> : Here is the ASP (VBScript) code that doesn't work:
> : Dim nStatus, ret, strReturn
> : Set nStatus = server.CreateObject("OEMaintenance.Status")
> : strReturn = "Not working"
> : nStatus.IsActive = true
> : nStatus.StatusType = "PAYMENT"
> : if nStatus.InsertNewStatus(strReturn) then
> : Response.Write strReturn
> : else
> : Response.Write strReturn
> : end if
> : Set nStatus = Nothing
> : Here is the error message
> : Microsoft VBScript runtime error '800a000d'
> :
> : Type mismatch: 'InsertNewStatus'
> :
> : /Maintain/Statuses.asp, line 13
> :
> : I can do this: strReturn = CSTR(strReturn) to make sure the variable is a
> : String, instead of variant, and still get the same number. the ByRef
> String
> : variable (strReturn) is required, and is the only one required. Currently
> I am
> : not setting the Description, so I should be getting a message back saying
> : Description is not currently defined.
> :
> : If I do:
> : If nStatus.InsertNewStatus("hi") it works, but obviously won't send me a
> : message.
> :
> : Is there any reason why I can't send a variable into a dll ByRef using
> ASP?
> :
> : TIA-
> : Mike S.
> 
> 

Hi there,

Variables passed by reference should indeed be pass ByRef. However, you can 
treat the passed reference as a local variable, so there is no need to 
create a local copy of it.

If you look at your own sample, you could see that. In the end, you assign 
ReturnMessage the value of TempString, so you _are_ acting on it.

Check out

http://support.microsoft.com/default.aspx?scid=KB;en-us;q197956

for a simple example of this.

Cheers,

Imar


At 06:28 AM 2/22/2003 +0000, you wrote:
>Ok, after much thought / research / coding and recoding I have found that
>solution.
>
>In the DLL change the BYREF argument to accept the datatype VARIANT. (Or 
>by not
>explicitly stating a datatype.) But, the key is that you can't act on that
>variable sent BYREF. (I have www.15seconds.com to thank)
>
>You have to declare a local variable to act on in the DLL, then reassign the
>value to the variable sent BYREF. For instance:
>
>Public function InsertText(byref ReturnMessage, byval Message)
>dim TempString as string
>TempString = ReturnMessage
>if Message = "" then
>   TempString = "InsertText.Message is improperly Defined."
>else
>   TempString = "InsertText Passed."
>end if
>ReturnMessage = TempString
>end function