Examples with PushConnection com.vaadin.flow.server.communication.PushConnection used on opensource projects

Example 1 with PushConnection

use of com.vaadin.flow.server.communication.PushConnection in project flow by vaadin.

the class UI method push.

/**
 * Pushes the pending changes and client RPC invocations of this UI to the
 * client-side.
 * <p>
 * If push is enabled, but the push connection is not currently open, the
 * push will be done when the connection is established.
 * <p>
 * As with all UI methods, the session must be locked when calling this
 * method. It is also recommended that {@link UI#getCurrent()} is set up to
 * return this UI since writing the response may invoke logic in any
 * attached component or extension. The recommended way of fulfilling these
 * conditions is to use {@link #access(Command)}.
 *
 * @throws IllegalStateException
 *             if push is disabled.
 * @throws UIDetachedException
 *             if this UI is not attached to a session.
 *
 * @see #getPushConfiguration()
 */
public void push() {
    VaadinSession session = getSession();
    if (session == null) {
        throw new UIDetachedException("Cannot push a detached UI");
    }
    session.checkHasLock();
    if (!getPushConfiguration().getPushMode().isEnabled()) {
        throw new IllegalStateException("Push not enabled");
    }
    PushConnection pushConnection = getInternals().getPushConnection();
    assert pushConnection != null;
    /*
         * Purge the pending access queue as it might mark a connector as dirty
         * when the push would otherwise be ignored because there are no changes
         * to push.
         */
    session.getService().runPendingAccessTasks(session);
    if (!getInternals().isDirty()) {
        // Do not push if there is nothing to push
        return;
    }
    pushConnection.push();
}

Example 2 with PushConnection

use of com.vaadin.flow.server.communication.PushConnection in project flow by vaadin.

the class UI method close.

/**
 * Marks this UI to be {@link #onDetach(DetachEvent) detached} from the
 * session at the end of the current request, or the next request if there
 * is no current request (if called from a background thread, for instance.)
 * <p>
 * The UI is detached after the response is sent, so in the current request
 * it can still update the client side normally. However, after the response
 * any new requests from the client side to this UI will cause an error, so
 * usually the client should be asked, for instance, to reload the page
 * (serving a fresh UI instance), to close the page, or to navigate
 * somewhere else.
 * <p>
 * Note that this method is strictly for users to explicitly signal the
 * framework that the UI should be detached. Overriding it is not a reliable
 * way to catch UIs that are to be detached. Instead,
 * {@code #onDetach(DetachEvent)} should be overridden.
 */
public void close() {
    closing = true;
    // FIXME Send info to client
    PushConnection pushConnection = getInternals().getPushConnection();
    if (pushConnection != null) {
        // Can't use UI.push() directly since it checks for a valid session
        if (getSession() != null) {
            getSession().getService().runPendingAccessTasks(getSession());
        }
        pushConnection.push();
    }
}