🔗 Mastering Uniface reconnect: Merging Disconnected Data with Live Components

Working with disconnected data sets is a common challenge in enterprise applications. Today, let's dive deep into Uniface's reconnect command - a powerful tool for merging XML, JSON, or Struct data back with live component occurrences and database connections. 🚀

This article is based on the official Uniface Documentation 10.4 and was created with AI assistance to help developers understand this essential command better.

📋 What is reconnect?

The reconnect command resolves modification state information stored in occurrence metadata after loading data using xmlload, webload, or structToComponent statements.

🔧 Syntax

reconnect {/readcheck} {EntityName}

⚙️ Parameters & Qualifiers

• /readcheck (optional): Ignores user modifications on read-only fields and restores values from database
• EntityName (optional): String specifying the component entity name

🎯 How It Works

The reconnect process follows a specific procedure based on occurrence modification states:

$occstatus	$occmod	$storetype	$occdel	Description
""	1	1	0	🆕 Treated as new occurrence
"new"	1	1	0	🆕 New occurrence
"est"	0	0	0	✅ Existing unmodified occurrence
"mod"	1	0	0	✏️ Existing modified occurrence
"del"	X	X	1	🗑️ Marked as deleted occurrence

🔒 Read-Only Field Handling

Fields become read-only when:

• Field syntax definition specifies NED (no edit allowed) 🚫
• Field syntax changed to NED at runtime via fieldsyntax or $fieldsyntax

Using the /readcheck qualifier will ignore user modifications to read-only fields and restore original database values. 🔄

📊 Return Values

• 0: ✅ Successful reconnection
• >0: ❌ Number of errors encountered (negative error trigger returns)

⚡ Performance Benefits

The reconnect statement intelligently merges only disconnected occurrences with modification states other than "est". This approach:

• 🚀 Improves performance significantly
• 🛡️ Avoids unnecessary CRC errors on unmodified occurrences
• 🎯 Uses ID property for efficient merging

💡 Practical Example

; Basic reconnect example
xmlload "/data/customer_updates.xml", "CUSTOMERS"
reconnect

; Reconnect with read-check for specific entity
xmlload "/data/orders.xml", "ORDERS"  
reconnect /readcheck ORDERS

; Check the result
if ($status = 0)
    message "Data successfully reconnected! ✅"
else
    message "Reconnect failed with %%$status%% errors ❌"
endif

🎉 Conclusion

The reconnect command is essential for modern Uniface applications handling disconnected data scenarios. Understanding its behavior with different occurrence states and proper use of qualifiers like /readcheck ensures reliable data synchronization and optimal performance.

Remember: reconnect works with all component types and automatically handles validation flags, modification states, and database locking when using cautious locking mode! 🔐

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