Package com.vaadin.flow.component

Interface PollNotifier

All Superinterfaces:
Serializable
All Known Implementing Classes:
UI, WebComponentUI
public interface PollNotifier extends Serializable
The interface for adding and removing PollEvent listeners.

By implementing this interface, a class publicly announces that it is able to send PollEvents whenever the client sends a periodic poll message to the client, to check for asynchronous server-side modifications.

Since:
1.0
See Also:

  • Method Details

    • addPollListener

      default Registration addPollListener(ComponentEventListener<PollEvent> listener)
      Add a poll listener.

      The listener is called whenever the client polls the server for asynchronous UI updates.

      Poll listeners are registered as "inert" tolerant, which means that they keep being invoked even while a modal component (such as a modal dialog) is open. Polling is a UI-level "global" feature that isn't tied to any specific component and doesn't pass any user-controlled data to the server, so it should not be blocked by a modality curtain.

      Parameters:
      listener - the listener to add
      Returns:
      a handle that can be used for removing the listener
      See Also: