SessionInitListener for a Vaadin 8.1 OSGI Portlet

Question

I can't seem to work out how to add SessionInitListener to a Vaadin 8.1 OSGI portlet running on Liferay 7.

In Vaadin 7 and Liferay 6.x it was done by simply defining a custom implementation of VaadinPortlet. Any help would be much appreciated.

Answer 1

This is possible. There is no need for a custom Portlet implementation.

All that is required is to add a SessionInitListener in the UI init method.

 @Override
    protected void init(final VaadinRequest vaadinRequest) {


        vaadinRequest.getService().addSessionInitListener(this::sessionInit);

Combined with a lambda, you can manupulate the HTML like this.

private void sessionInit(final SessionInitEvent sessionInitEvent) {
    sessionInitEvent.getSession().addBootstrapListener(new BootstrapListener() {
        @Override
        public void modifyBootstrapFragment(final BootstrapFragmentResponse response) {
            Element myDiv = new Element(Tag.valueOf("div"), "");
            myDiv.append("<h1>Extra HTML!</h1>");
            List<Node> nodes = response.getFragmentNodes();
            for (Node node : nodes) {
                myDiv.appendChild(node);
            }
            nodes.clear();
            nodes.add(myDiv);
        }

        @Override
        public void modifyBootstrapPage(final BootstrapPageResponse bootstrapPageResponse) {

        }
    });
}