Working with file operations in Uniface can be tricky, especially when dealing with ZIP archives and XML files. Today, I want to share insights about one of the most useful yet underutilized commands in Uniface ProcScript: the flush statement. 💾

Note: This article is based on the Uniface Documentation 10.4 and was created with assistance from AI to ensure accuracy and clarity.

🤔 What is the flush Command?

The flush command in Uniface is designed to complete file management transactions for open ZIP archives or XML files, then close them properly. Think of it as a "save and close" operation that ensures your file operations are properly finalized.

📝 Syntax

flush "ZipArchive:" | "XmlFile"

🎯 Why Use flush?

Uniface keeps files open during operations to avoid performance issues from repeatedly opening and closing files. This is particularly beneficial when:

• 📁 Working with ZIP archives containing multiple files
• 🔄 Repeatedly using $ude("export") or $ude("copy") with the keepopen option
• ⚡ Performing multiple file operations in sequence

💡 Practical Examples

Example 1: Flushing ZIP Files 📦

Here's how to write data to a file within a ZIP archive and properly close it:

filedump "abc", "C:/Uniface/Uniface96_Data/project/b5.zip:dir1/def.txt"
flush "C:/Uniface/Uniface96_Data/project/b5.zip:"

This example writes "abc" to def.txt inside the dir1 directory within the b5.zip archive, then flushes and closes the ZIP file.

Example 2: Flushing Export Files 📤

When exporting multiple components, you can keep the file open and flush at the end:

vOut = $ude("export", "model", "*", "myexport.xml", "keepopen=true")
vOut = $ude("export", "component", "*", "myexport.xml", "keepopen=true;append=true")
flush "myexport.xml"

This approach exports all models and components to the same XML file efficiently, then completes the transaction.

🔧 Key Parameters

🎯 Best Practices

• ✅ Always flush after completing a series of file operations
• ✅ Use absolute paths when possible to avoid confusion
• ✅ Remember that flush takes assignment file redirections into account
• ✅ If no absolute path is specified, the file location defaults to the Uniface project directory

⚠️ Important Notes

The flush command is allowed in all Uniface component types, making it a versatile tool for file management across your entire application. Remember to always flush your files to ensure data integrity and proper resource management! 🛡️

🎉 Conclusion

The flush command might seem simple, but it's essential for robust file management in Uniface applications. By properly closing your ZIP archives and XML files, you ensure better performance and data integrity in your applications.

Have you used the flush command in your Uniface projects? Share your experiences in the comments below! 💬

Happy coding with Uniface! 🚀