Using Ajax With WebSockets

Java Platform, Enterprise Edition (Java EE) 8
The Java EE Tutorial

Using Ajax With WebSockets

If you want to perform complex UI updates depending on the received push message, you can nest the f:ajax tag inside the f:websocket tag. See the following example:

<h:panelGroup id="foo">
... (some complex UI here) ...
</h:panelGroup>
<h:form>
<f:websocket channel="someChannel" scope="view">
<f:ajax event="someEvent"
listener="#{bean.pushed}" render=":foo" />
</f:websocket>
</h:form>

Here, the push message simply represents the ajax event name. You can use any custom event name.

someChannel.send("someEvent");

An alternative is to combine the f:websocket tag with the h:commandScript tag. The <f:websocket onmessage> references exactly the <h:commandScript name>.

For example:

<h:panelGroup id="foo">
... (some complex UI here) ...
</h:panelGroup>
<f:websocket channel="someChannel" scope="view"
onmessage="pushed" />
<h:form>
<h:commandScript name="pushed"
action="#{bean.pushed}" render=":foo" />
</h:form>

If you pass a Map<String,V> or a JavaBean as the push message object, then all entries or properties will transparently be available as request parameters in the command script method #{bean.pushed}.

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