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🚀 Understanding Uniface $disable Function: Menu Item Control Made Simple

✨ This blog post was created with AI assistance to help developers understand Uniface better.

👋 Hey developers! Today we're diving into one of Uniface 10.4's handy built-in functions: $disable. This little function is your friend when you need to control menu items in your Uniface applications.

🤔 What Does $disable Do?

The $disable function is used to disable or enable menu items in menu objects. Think of it as a switch that makes menu items clickable or grayed out (dimmed). When a menu item is disabled, users can't click on it, and even the keyboard shortcuts won't work! 🚫

📝 How to Use It

Here's the simple syntax:

set | reset $disable
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Important note: You can only use this function in the preDisplay trigger of Menu objects. This makes sense because you want to set the menu state before it shows up to users! 🎯

Return Values 📊

  • 0 = Menu item is selectable (enabled) ✅
  • 1 = Menu item is not selectable (disabled) ❌

💡 Practical Examples

Example 1: Simple Disable

Here's how to disable a menu item:

trigger preDisplay
    set $disable
end; preDisplay
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This code runs before the menu appears and disables the current menu item.

Example 2: Toggle Function

You can also flip the current state like this:

$disable = !$disable
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This is super useful when you want to toggle between enabled and disabled states based on conditions! 🔄

Example 3: Conditional Logic

Here's a more real-world example:

trigger preDisplay
    if (userLevel < 3)
        set $disable  ; Disable for low-level users
    else
        reset $disable  ; Enable for high-level users
    endif
end; preDisplay
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🔧 Best Practices

  • Always use in preDisplay: Remember, this only works in the preDisplay trigger of menu objects
  • Check for errors: If something goes wrong, check $procerror for error details
  • User experience: Disabled items are automatically dimmed, giving users clear visual feedback
  • Accessibility: Both mouse clicks and keyboard shortcuts are disabled together

🚨 Common Mistakes to Avoid

  • Don't try to use $disable outside of menu preDisplay triggers
  • Remember that setting it to any non-zero value makes it disabled (not just 1)
  • Don't forget to handle error conditions with $procerror

🎉 Wrapping Up

The $disable function is a simple but powerful tool for creating dynamic menus in Uniface applications. Whether you're building role-based menus or context-sensitive interfaces, this function helps you control what users can and cannot access.

Happy coding! 🎯

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