From a UI perspective, Events in WoW are messages sent by the WoW client to the UI Frames (via frame script handlers), mostly in reaction to things occurring in the game world. See the [[#Event Index|Event API Index] links below for event reference.
- Indexed Events (API)
- List of all Events (API)
- Communication Events
- Glue Events
- Events that fire during the Loading Process
- Handling events - a tutorial on how to set up event handling in your addon.
- Parsing event messages - extracting information from events with textual parameters.
The World of Warcraft interface is entirely event driven: all interface code is invoked in response to an event (or OnUpdate "events"). All script execution must be completed before a frame is rendered; therefore, event processing code that takes too long or contains an infinite loop will freeze the client.
You can register your Frame-derived widget to receive an event using the frame:RegisterEvent("eventName") function. When the events occur, they will be delivered to the OnEvent script handler, which can be set using frame:SetScript("OnEvent", handlerFunc). To unregister an event, use frame:UnregisterEvent("eventName").