Which event cannot be triggered by a screen?

The event that cannot be triggered by a screen is related to the OnParametersChanged event. This specific event is associated with the logic that handles changes in the parameters passed to a screen or a block but is not a screen-specific event. Instead, it is more applicable to aggregates or other components that handle data filtering or binding.

OnMicroflowComplete, OnClick, and OnReady are all events specifically related to screens. OnMicroflowComplete is triggered when a microflow initiated from the screen finishes executing, allowing for follow-up actions based on that completion. OnClick is a user interaction event that occurs when a user clicks an element within the screen, often utilized for buttons or other clickable components. OnReady is emitted when the screen has finished rendering, signaling that it is now ready for user interaction.

Understanding these distinctions highlights how event handling operates within OutSystems, allowing developers to manage functionality based on user interactions and screen lifecycle events. This focuses on enhancing the user experience and ensuring that applications respond appropriately to a variety of situations.