rich:progressBar currentValue does not working with For-Loop? - jsf

Question

In RichFaces 4.1, rich:progressBar 'currentValue' from the ManagedBean does not updating with for-loop.
progressBar.xhtml
<h:form id="formProgress">
<h:commandLink action="#{progressBarBean.startProcess}" value="click here"/>
<rich:progressBar mode="ajax" value="#{progressBarBean.currentValue}" interval="1000" id="pb"
enabled="#{progressBarBean.enabled}" minValue="0" maxValue="100">
<h:outputText value="Retrieving #{progressBarBean.currentValue} of #{progressBarBean.totalRecords}" />
</rich:progressBar>
</h:form>
Bean
package ap;
import java.io.Serializable;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
#ManagedBean
#ViewScoped
public class ProgressBarBean implements Serializable {
private static final long serialVersionUID = 8775622106408411357L;
private boolean enabled = false;
private Integer totalRecords;
private Integer currentValue;;
public String startProcess() {
setEnabled(true);
setTotalRecords(100);
return null;
}
public Integer getCurrentValue() {
if (isEnabled()) {
for(currentValue=0;currentValue < totalRecords;) {
currentValue++;
}
}
return currentValue;
}
public boolean isEnabled() {
return enabled;
}
public void setEnabled(boolean enabled) {
this.enabled = enabled;
}
public Integer getTotalRecords() {
return totalRecords;
}
public void setTotalRecords(Integer totalRecords) {
this.totalRecords = totalRecords;
}
}
When i click the 'click here' link, the currentValue updates very fastly and reaches the totalRecords to 100 suddenly. It was not updating in the incremental way(present value in for-loop). The progress bar is not updated by the present value return by the method.
Any help please.

Answer 1

There are two problems: your Java code does not do what you want it to do and you're not telling the page to update (that won't happen automatically).
Take a look at the getCurrentValue() again: It increments currentValue from 0 to 100 and returns the result which is 100. #{progressBarBean.currentValue} does not care (or know) what happens with the variable, it only cares about the result of the getCurrentValue() method.
So in order for it all to work it will have to look like this:
Page
<a4j:commandLink action="#{progressBarBean.startProcess}" value="click here" render="pb" execute="#this"/>
<rich:progressBar mode="ajax" value="#{progressBarBean.currentValue}" interval="1000" id="pb"
enabled="#{progressBarBean.enabled}" minValue="0" maxValue="100">
<a4j:ajax event="begin" listener="#{progressBarBean.increment}" render="text"/>
<h:outputText value="Retrieving #{progressBarBean.currentValue} of #{progressBarBean.totalRecords}" id="text" />
</rich:progressBar>
The a4j:ajax is fired each second (i.e. each interval), it increments the currentValue and updates the text.
You also need a4j:commandLink (or a4j:ajax inside the h:commandLink) in order to rerender the progressbar - in your example you enable the progressbar in the bean but the value on the page does not change.
Bean
public Integer getCurrentValue() {
return currentValue;
}
public void increment() {
if (isEnabled() && currentValue < totalRecords) {
currentValue++;
}
}
Ask if anything isn't clear.