Polling – sending periodical AJAX requests
Polling is a way to poll a server periodically in order to trigger server-side changes or update parts of a web page. The polling technology in PrimeFaces is represented by the poll component. It is an AJAX-ified component that has the ability to send periodical AJAX requests.
In this recipe, we will update a feed reader periodically to show current sports news. A growl component will be updated with the same interval too in order to show the time of the last feed update.
How to do it…
The p:poll component in the following code snippet invokes the showMessage() listener method every 10 seconds and updates a feed reader and a growl. The listener method generates the current time. Furthermore, we will define a widget variable in order to stop or start polling using the client-side API. This occurs via command buttons. Take a look at the code for this discussion:
<p:growl id="growl"/> <p:poll id="poll" listener...
