Events to propagate changes from a block to the parent
We can develop our frontend in pages or blocks. The latter are considered groupings of certain features and samples that live in their own lifecycle and with their own scope and can be reused within other blocks and/or screens. Direct or indirect recursion using blocks is not possible, that is, a block has an instance of itself in its content.
Since a block has its own scope, in order to communicate with its parent, be it another block or a screen, you need to trigger events to do so. These same events can carry data, defined as input variables.
When we define an event in a certain block, if it has its Is Mandatory property set to Yes, the parents of that block must define a handler, which can be a screen action or another event, to respond to the change made to the child block.
Tip
If you want to see a brief explanation and example of how to set up an event and its handler between a block and a parent, you can see...