Errors

VBA Error Handling Flow Summary

Step	Description
On Error GoTo Label	Sets the error handler label; redirects to this label if a runtime error occurs.
Normal code execution	Runs code normally until an error occurs or procedure ends (via Exit Sub/Function).
Error occurs	Execution jumps immediately to the error handler label.
Error Handler block	Executes error handling code (e.g., logging, cleanup, user messages).
Resume statements	Control flow options after error handling:
- Resume	Re-execute the error-causing line (retry).
- Resume Next	Skip the error line; continue with the next statement.
- Resume	Jump to a specific label (often cleanup) before continuing or exiting.
Exit Sub/Function before handler	Prevents normal code from running into the error handler block accidentally.
Cleanup code (optional)	Frees resources or resets state before exiting or continuing.
End of procedure	When no error or after error handling with no resume, execution ends at End Sub/Function.

modErrorHandler

This module contains a general error handler.

Usage:

After declarations, add this

On Error GoTo Error_Handler

Add the module code and then

Cleanup:
    Set openObject = Nothing
    Exit Function

Error_Handler:
    GeneralErrorHandler err, Me.Name, "ReplaceWithProcedureName"
    Resume Cleanup
End Function

Or for a subroutine

Cleanup:
    Set openObject = Nothing
    Exit Sub

Error_Handler:
    GeneralErrorHandler err, Me.Name, "ReplaceWithProcedureName"
    Resume Cleanup
End Sub

Cleanup with object

Cleanup:
    Set openObject = Nothing
    Exit Sub

Cleanup without object

Cleanup:
    Exit Sub

From error

Error_Handler:
    GeneralErrorHandler err, Me.Name, "ReplaceWithProcedureName"
    Resume Cleanup

Module error

Error_Handler:
    GeneralErrorHandler err, MODULE_NAME, "ReplaceWithProcedureName"
    Resume Cleanup

Nz Function Summary

Argument	Description
variant (required)	The value to check for Null (can be a field, control, variable).
valueifnull (optional)	The value to return if variant is Null. Defaults to 0 for numbers, "" for strings (but specifying it explicitly is best).

• Returns variant if not Null.
• Returns valueifnull if variant is Null.
• Useful to avoid runtime errors when Null values might occur.
• Best practice: always specify valueifnull, especially for strings, to ensure consistent results.