UI Controllers

By setting the controller attribute on an XML frame, the engine will run the associated Lua script automatically when the UI frame is created and deliver events (such as OnEnable/OnDisable) to the Lua script. This makes it easier to customize UI frames in Lua and allows you to create reusable UI components with a combination of XML and Lua. Such Lua scripts also work in the UI previewer so you can iterate on UI related Lua code (like UI animations) much faster without the need to start the entire game.

Use Cases

• Tie a script file to a XML file
• Faster iteration by previewing UI animations in the UI previewer
• Reusability - Define reusable animations as their own script files

Events sent to Lua

• OnEnable Sent when the frame becomes active (visible)
• OnDisable Sent when the frame becomes inactive (hidden)
• OnPreview Sent automatically when viewed in the UI previewer. Note that OnPreview is only sent to the root layout and not any includes.

Relevant Lua APIs

• DCEI.GetFrameController

Relevant XML Attributes

• controller script_file_name

Example Map

https://platform.wildsky.dev/arcade/game/606 (Click “Source” to download)

Example