DerivedFileManager is an example project showcasing how to extend the ABC FileManager in Clarion. It includes two Clarion files: ModFM.INC (a class definition) and ModFM.CLW (source code), which derive from the ABC FileManager. This extension adds several methods to enhance the functionality of the original FileManager, making it more versatile, especially for SQL file management.

The DerivedFileManager class introduces the following methods to the ABC FileManager:

• IsSQLFile: Determines if the file is an SQL file.
• DBTraceOn: Activates Clarion table tracing for the file, with output directed to OutputDebugString.
• DBTraceOff: Deactivates Clarion table tracing for the file, stopping output to OutputDebugString.
• TRACE: Sends a message to OutputDebugString, prefixed by the table name.

Additionally, the derived Init method demonstrates setting the file's PROP:Alias to the prefix of the file, a technique beneficial for SQL definitions.

To integrate DerivedFileManager into your Clarion projects, follow these steps:

1. Copy ModFM.INC and ModFM.CLW to your ClarionDirectory\Accessories\libsrc\Win directory.
2. For each application that requires DerivedFileManager, navigate to the Global Properties:
   • Go to Actions > Classes Tab > File Management.
   • Select ModFM from the FileManager dropdown menu.

This process ensures that your application uses the enhanced file management capabilities provided by DerivedFileManager.

To control tracing for a specific file manager instance, you can use the DBTraceOn and DBTraceOff methods. Here's how you might do it:

! To turn on tracing for a table
ACCESS:TableName.DBTraceOn()

! To turn off tracing for the same table
ACCESS:TableName.DBTraceOff()

! Sending a custom trace message
ACCESS:TableName.TRACE('Your custom message here')