Ajax update executes once though event occurs many times
Question
I'm starting to learn Primefaces framework, based on JSF and AJAX and I'm having some trouble.
I was trying a simple example such as having an inputText and I was trying to set a counter that increments its value every time a key is pressed on the inputText . To do this I used AJAX and a Bean. The problem is that the counter only is increased the first time, after that it remains the same. Here's my code:
WEB PAGE
<!DOCTYPE html>
<html xmlns:h="http://java.sun.com/jsf/html"
xmlns:p="http://primefaces.org/ui">
<h:head>
<title>AJAX LISTENER</title>
</h:head>
<h:body>
<h:form>
<h:inputText id="counter">
<p:ajax update="out" event="keypress" listener="#{counterBean.increment}"/>
</h:inputText>
<br/>
AJAX listener = <h:outputText id="out" value="#{counterBean.count}" />
</h:form>
</h:body>
</html>
BEAN
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
@ManagedBean
@RequestScoped
public class counterBean {
private int count;
public counterBean() {
this.count = 0;
}
public void increment(){
this.count = this.count +5;
}
public void setCount(int count) {
this.count = count;
}
public int getCount() {
return count;
}
}
2 answers
solution1
0 2014-03-21 15:25:09
Refer to : http://www.primefaces.org/documentation
In your case the better event is keyup I don't think it has a keypress event in primefaces.
Section 8.3 in the user guide 4.0
- Ok your answer is actually very simple, I did testing and after finally realising the stupidity of it all...
Your ManagedBean is only RequestScoped - thus it's getting re-initalised every request... Change it to @ViewScoped.
A great doco on beans is : http://balusc.blogspot.com.au/2011/09/communication-in-jsf-20.html#ManagedBeanScopes
solution2
0 ACCPTED 2014-03-21 16:46:25
该bean需要进行观察。
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