How do blocks communicate with their parent in OutSystems?

In OutSystems, blocks communicate with their parent through triggered events in screen actions. This mechanism allows for a structured and event-driven communication model, enabling parent screens or higher-level blocks to receive notifications or updates from their child blocks.

When a child block triggers an event, it can pass data back to the parent, which can then handle that event appropriately—whether it’s updating the UI, performing logic, or triggering other actions. This method promotes decoupling between components, as the child block does not need to have knowledge about the parent’s implementation, only that it can send events.

This approach is much more aligned with best practices in component-based architecture compared to other methods like direct variable access or global parameters, which can lead to tighter coupling and reduced modularity. Instead of relying on shared variables, which can create dependencies that make maintenance and testing challenging, using events allows each component to operate independently while still facilitating communication.