Const NULLHANDLE = 0
Const NO_ERROR = 0
Const ERR_FORMULA_COMPILATION = &h500 + 1

' ================================================================================
' CheckSelectionFormulaValid - 
' This function uses the Lotus C API to check the syntax of a Notes formula.
' Return Value: Variant - A 3 elements array containing:
' Index 0 - The compilation error code or NO_ERROR (0) if valid
' Index 1 - The compilation error offset in formula or NO_ERROR if valid 
' Index 2 - The compilation error length or NO_ERROR if valid
'
' Note: The compilation error code at Index 0 can then be passed to GetAPIError() 
' to get more info about the error.
' ================================================================================
' ================================================================================
' GetAPIError - This function uses the Lotus C API to return 
' a Notes error's text message.
'
' Return Value: String - The text associated with the Notes API error code.
' ================================================================================

Declare Function NSFFormulaCompile Lib "nnotes.dll" ( _
Byval FormulaName As Long, _
Byval FormulaNameLength As Integer, _
Byval FormulaText As Lmbcs String, _
Byval FormulaTextLength As Integer, _
rethFormula As Long, _
retFormulaLength As Integer, _
retCompileError As Integer, _
retCompileErrorLine As Integer, _
retCompileErrorColumn As Integer, _
retCompileErrorOffset As Integer, _
retCompileErrorLength As Integer _
) As Integer

Declare Sub OSMemFree Lib "nnotes.dll" (Byval hHandle As Long)

Declare Function OSLoadString Lib "nnotes.dll" ( _
Byval hmodule As Long, _
Byval status As Integer, _
Byval s As String, _
Byval slen As Integer _
) As Integer


Function CheckSelectionFormulaValid(sFormula) As Variant
	
	Dim iError As Integer
	Dim hFormula As Long
	Dim wFormulaLen As Integer
	Dim iCompileError As Integer
	Dim iCompileErrorLine As Integer
	Dim iCompileErrorColumn As Integer
	Dim iCompileErrorOffset As Integer
	Dim iCompileErrorLength As Integer
	Dim iArray(2) As Integer
	
	iError = NSFFormulaCompile(0, 0, _
	sFormula, _
	Len(sFormula), _
	hFormula, _
	wFormulaLen, _
	iCompileError, _
	iCompileErrorLine, _
	iCompileErrorColumn, _
	iCompileErrorOffset, _
	iCompileErrorLength)
	
	If hFormula <> NULLHANDLE Then
		Call OSMemFree(hFormula)
	End If
	
	If iError = ERR_FORMULA_COMPILATION Then
		iArray(0) = iCompileError
		iArray(1) = iCompileErrorOffset
		iArray(2) = iCompileErrorLength
		CheckSelectionFormulaValid = iArray
	Else
		iArray(0) = NO_ERROR
		iArray(1) = NO_ERROR
		iArray(2) = NO_ERROR
		CheckSelectionFormulaValid = iArray
	End If
	
End Function

Function GetAPIError(iErrorCode As Integer) As String
	
	Dim iRetVal As Integer
	Dim sError As String * 1024
	
	sError = String(1024, 0)
	
	iRetVal = OSLoadString(0&, iErrorCode, sError, 1023)
	
	If iRetval <> 0 Then
		GetApiError = Left$(sError, iRetVal)
	End If
	
End Function