Package org.silverpeas.core.notification.sse

Interface ServerEvent

  • All Known Subinterfaces:
    AfterSentToAllContexts, IgnoreStoring, KeepAlwaysLastStored, SendEveryAmountOfTime, StoreLastOnly
    All Known Implementing Classes:
    AbstractServerEvent, CommonServerEvent, UserNotificationServerEvent, UserSessionServerEvent
    public interface ServerEvent
    An event implying data the server has to push to client without the client requesting Silverpeas. This event is called Server Event.
    Three elements compose a server event:
    • id, an identifier that identifies the event
    • name, the name of the event. It can be taken like the name of a bus. This name is used by client to add listeners. For example, il the name of an event is USER_SESSION the client (in JavaScript) can listen to by coding 
           new EventSource(...).addEventListener('USER_SESSION', function(serverEvent){
       ...
     })
    • data, textual data (but it is not forbidden to render JSON structure as string)
    Author:
    Yohann Chastagnier

    • Method Detail

      • isValidId

        default boolean isValidId()
        Indicates if identifier is a valid one.

        BE CAREFUL, this method calls getId() method and it could so generates the identifier.

        Returns:
        true if valid, false otherwise.

      • getId

        long getId()
        Gets the identifier of the server event.
        This identifier is unique during the lifetime of the server. After the server is restarted, the counter starts again to zero.
        Returns:
        the name as unique ServerEvent.ServerEventName instance.

      • subType

        default String subType()
        Gets the sub type the event if any.
        Returns:
        the sub type of the event if any, empty string otherwise.

      • getData

        String getData​(String receiverSessionId,
               User receiver)
        The data to send.
        Parameters:
        receiverSessionId - the identifier of the receiver session.
        receiver - the user that will receive the event in its WEB client.
        Returns:
        the data as string.

      • isConcerned

        default boolean isConcerned​(String receiverSessionId,
                            User receiver)
        Indicates if the given receiver (behind the session) is concerned by the event. If not, the event is not sent.
        Parameters:
        receiverSessionId - the identifier of the receiver session.
        receiver - the user that will receive the event in its WEB client.
        Returns:
        true if given receiver is concerned, false otherwise.

      • send

        default boolean send​(SilverpeasServerEventContext context,
                     String receiverSessionId,
                     User receiver)
              throws IOException
        Sends the event by using the given response and taking into account the receiver linked to.
        If isConcerned(String, User) indicates that the given receiver is not concerned, nothing is sent.
        Parameters:
        context - the context from which the communication has been opened.
        receiverSessionId - the identifier of the receiver session.
        receiver - the receiver instance.
        Returns:
        true if send has been performed, false otherwise.
        Throws:
        IOException - if the sending fails.