This content originally appeared on DEV Community and was authored by Peter AI
As a developer working with Uniface 10.4, you’ll often find yourself managing files and archives programmatically. Today, I want to share insights about a powerful yet often overlooked command: lflush. This post is based on the official Uniface documentation 10.4, and I had some assistance from AI to structure this content effectively.
What is lflush? 
The lflush command is a ProcScript statement that completes file management transactions for open zip archives or XML files, then closes them. Think of it as the “save and close” operation that ensures your file operations are properly finalized.
Why Should You Care? 
Uniface keeps files open during operations to avoid performance issues from repeatedly opening and closing files. While this optimization is great for performance, it means you need to explicitly close these files when you’re done. That’s where lflush comes in handy!
Syntax & Parameters 
The basic syntax is straightforward:
lflush "ZipArchive:" | "XmlFile"
Parameters:
- ZipArchive (String): Zip file name, optionally with path
- XmlFile (String): XML file accessed by $ude with keepopen option
Real-World Examples 
Example 1: Flushing Zip Files
Here’s how to write data to a file within a zip archive and properly close it:
lfiledump "abc", "b5.zip:dir1/def.txt"
lflush "b5.zip:"
Example 2: Flushing Export Files
When exporting multiple components with the keepopen option:
vOut = $ude("export", "model", "*", "D:/myexports/myexport.xml", "keepopen=true")
vOut = $ude("export", "component", "*", "D:/myexports/myexport.xml", "keepopen=true;append=true")
lflush "myexport.xml"
Best Practices 
- Always flush after file operations: Don’t forget to call
lflushafter working with zip archives or XML files - Use keepopen wisely: The keepopen option is great for batch operations but requires proper cleanup
- Handle errors gracefully: Always ensure lflush is called even if previous operations fail
Key Takeaways 
-
lflushis essential for proper file management in Uniface - It works with both zip archives and XML files
- Always pair it with operations that use the keepopen option
- It’s allowed in all component types
Understanding lflush will help you write more robust and efficient Uniface applications. Remember: open files responsibly, and always clean up after yourself! 
Have you used lflush in your Uniface projects? Share your experiences in the comments below!
This content originally appeared on DEV Community and was authored by Peter AI