https://github.com/BriargateExcel/Error_Handling

VBA code handling errors
https://github.com/BriargateExcel/Error_Handling

Last synced: 4 months ago
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VBA code handling errors

• Host: GitHub
• URL: https://github.com/BriargateExcel/Error_Handling
• Owner: BriargateExcel
• Created: 2020-06-28T16:49:05.000Z (almost 5 years ago)
• Default Branch: master
• Last Pushed: 2020-07-19T15:25:45.000Z (over 4 years ago)
• Last Synced: 2024-06-18T00:38:30.452Z (10 months ago)
• Language: VBA
• Size: 7.81 KB
• Stars: 2
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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• jimsghstars - BriargateExcel/Error_Handling - VBA code handling errors (VBA)

README

        
**Error Handling for Excel VBA Code**

I have an error handling scheme I’ve devised over years of writing VBA code for Excel.

**The structure:**

- Code module called `Error_WarningRoutines`

- Class module called `MessageFileClass`

- I have a module I include in every application called `CommonRoutines`. This error handling scheme uses one routine in `CommonRoutines` called `DesktopFolder`. `DesktopFolder` returns a String containing the path to the user’s Desktop folder.

**How to Use the Error Management Scheme:**

- Include `ErrorWarning_Routines`, `MessageFileClass`, and `DesktopFolder` in your VBA code

- Use the `MainProgramTemplate` for your top-level routines

- Use the `SubTemplate` as the pattern for your routines

**How it Works**

- When your code raises an exception, execution jumps to `ErrorHandler`. The error handler code calls `ReportError` in `Error_WarningRoutines`.

- `ReportError` starts an error file if this is the first error. More on error files later. `ReportError` creates an `Error Messages` folder on the user's desktop if one doesn't already exist. `ReportError` finds the next unused `Error MessagesXX.txt` file by incrementing `XX` through all the used numbers.

- `ReportError` writes an error message to the error file.

- Execution returns to the error handler code in your routine.

- The error handler calls `RaiseError` in `Error_WarningRoutines`

-  `RaiseError` raises the error to the next higher routine in the call stack

- The error is eventually raised to the top-level routine (`MainProgramTemplate`)

- The `MainProgram` error handler calls `CloseError` in `Error_WarningRoutines`

- `CloseError` closes the error file by setting the file’s class instance to Nothing. This triggers the `Class_Terminate` routine in `MessageFileClass`.

- `Class_Terminate` closes the file and alerts the user that they should look on their desktop for an Error Messages folder where the user will find the error file

**What the User Sees:**

- When the program raises an error, the user sees a `MsgBox` alerting them to look in the `Error Messages` folder on their desktop

- In the `Error Messages` folder, the user sees `Error MessagesXX.txt` error file(s)

- The user can open the most recent `Error MessagesXX.txt` error file to see the error messages

**Options:**

- There is a `ReportError` and a `ReportWarning` routine in `Error_WarningRoutines`. You, as the programmer, have an option to use either routine depending on the severity of the error. My practice is to put detailed “what happened in the code” messages in the error files for the programmer. I put application-oriented messages in the messages in the warning files. As the programmer I lean on the error files. The user should rely on the warning files. You, as the programmer, must make that distinction in your code.

- `MessageFileClass` is a general-purpose class you can use any time you need to write to a .txt file