Anyone who has developed JSF 2 applications for any length of time, will have come across the issue that element focus may get lost when AJAX rendering is preformed.
So what is the cause of this? I have constructed a simple webapp to demonstrate the issue and show a potential solution.
One of the simplest possible scenario is a simple value change event that triggers a render on the following field:
[xhtml]
<h:outputLabel value="Input field: " />
<h:inputText id="firstValue" value="#{sessionBean.firstValue}" tabindex="1">
<f:ajax event="change" render="secondValue thirdValue" />
</h:inputText>
<h:outputLabel value="Render to Upper field: " />
<h:inputText id="secondValue" value="#{sessionBean.secondValue}" tabindex="2" />
[/xhtml]
On the server side we are simply preforming a toUpper on the firstInput and assigning it to the secondValue. In this case implemented as a simple session scoped CDI bean, the underlying backing bean infrastructure has no influence on the response that JSF produces or how it is treated by the client.
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