Can an Event Handler be defined at the Screen level?

An Event Handler cannot be defined at the Screen level, which confirms the choice selected. Event Handlers in OutSystems are specifically designed to respond to user interactions or system events that are often more localized within specific components or objects rather than the screen as a whole.

In practice, Event Handlers are typically defined within UI elements like buttons, inputs, or other interactive components that reside within the screen. This is because these handlers are intended to capture and respond to interactions happening on those individual UI elements rather than at the screen level which encompasses multiple components.

This design choice facilitates better organization and modularity within an OutSystems application, allowing for more maintainable and scalable code. While Event Handlers can indeed be present in blocks, which serve as reusable components, defining them at the screen level generally isn't applicable since the concept of event handling is more closely tied to specific interactions with component elements.

Overall, the restriction of Event Handlers from the screen level aligns with the architecture and design principles employed in OutSystems for creating efficient and interactive web applications.