Understanding the Uniface Display Statement: Creating Read-Only Forms 📖

What is the Display Statement? 🎯

The display statement in Uniface is a powerful tool that presents forms on the screen as display-only, meaning users can view the data but cannot modify it. This is particularly useful for creating read-only interfaces or confirmation screens.

Basic Syntax 📝

display{/menu} {LitFieldName}

Example:

display CLIENT_DETAIL

Key Features and Parameters 🔧

Qualifiers

• /menu - Activates the menu trigger at field, entity, form, or application level when the form appears

Parameters

• LitFieldName (Literal) - The name of the field where the cursor should be positioned
  • Don't enclose in quotation marks
  • If omitted, cursor positions on the first painted field (top-left corner)

Return Values 📊

The $status variable returns different values based on user actions:

Value	Meaning
10	User used ^QUIT to leave the form
9	User used ^ACCEPT to leave the form
0	Success
-16	Application running in batch mode

Common Error Codes ⚠️

Watch out for these common errors returned by $procerror:

• -33 - Statement not allowed in batch mode
• -1401 - Prompted field not valid
• -1402 - Statement not allowed in this trigger (must be in exec operation)

Practical Example 💡

Here's a real-world example showing how to use the display statement:

operation exec
     CUST_NBR = $1
     retrieve
     message "%%$hits customers match search profile"
     display CUSTNAME
end; exec

This code:

1. Sets the customer number from a parameter
2. Retrieves the customer data
3. Shows a message with the number of matches
4. Displays the customer name field in read-only mode

Important Usage Notes 📌

• ✅ Can only be used in Form components
• ✅ Must be within an exec operation
• ✅ Alternative: Use newinstance with DISPLAY=TRUE
• ✅ Alternative: Use run/display to start forms in display-only mode
• ⚠️ Test for $batch to avoid batch mode errors

Best Practices 🏆

• Always handle the return values to provide proper user feedback
• Use meaningful field names for cursor positioning
• Consider the user experience when choosing between display modes
• Test your forms in different scenarios to ensure proper behavior

Conclusion 🎉

The Uniface display statement is an essential tool for creating read-only user interfaces. By understanding its syntax, parameters, and return values, you can build more robust and user-friendly applications.

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

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