H:selectBooleanCheckbox valuechangelistener help

Question

Hi all,
I have a page with a dataTable that holds information about sales items. On the first visit to the page, the table is displayed normally and sorted by price. It takes a Result as its collection so any sorting is done in SQL. I want to support grouping the items by quantity as well so I used the t:dataTable component and specified a groupBy column. Outside of the table, I have an h:selectBooleanCheckbox that has a value of myBean.groupByQuantity, a valueChangeListener, and an onchange="this.form.submit()". The groupByQuantity boolean is also used in the t:column as the groupBy value. The value change listener checks the value of the groupByQuantity boolean and runs an appropriate query (to order by price or quantity).
Some relevant code:
<t:dataTable value="#{myBean.items}" var="item" groupByStyle="groups">
   <t:column>
    <t:column groupBy="#{myBean.groupByQuantity}">
       <h:outputText value="#{item.quantity}"/>
    </t:column>
</t:dataTable>
<h:selectBooleanCheckbox value="#{myBean.groupByQuantity}"
valueChangeListener="#{myBean.processValueChangeEvent}"
onclick="this.form.submit()"/>In the MyBean.java
public class MyBean{
private boolean groupByQuantity = false;
//getters and setters for groupByQuantity
public void processValueChangeEvent(ValueChangeEvent vce){
   if (!groupByQuantity){
     //run SQL to order by quantity
   }else{
     //run SQL to order by price
public String goBackToList(){
   //run SQL to order by price
   groupByQuantity = false;
}When using the checkbox to toggle the value of groupByQuantity, the code acts as expected (except for the fact that it seems as if the checkbox is submitting the opposite value as it should which is why the two have to be reversed). However, if a user leaves the page and comes back using the goBackToList method, the checkbox keeps whatever state it was in when the application navigated away from the page even though I explicitly set the value to false and secondly, if the value was true then the application runs the query to order by price but the group by style is being displayed but if it is false, the query to run the order by quantity is run and the group by style is not displayed.
Having this information, I can see two problems but do not understand why they are happening. The first is that when I navigate to the page, the valueChangeListener event is being called even though I have not touched the checkbox. This must be happening because that method is the only place where there is a query to order by quantity. The other problem is that the value that is getting submitted to the backing bean and the value that is being reflected by the checkbox and groupBy attributes are not the same value. Has anyone had a similar problem? Does anyone have any advice on how to fix this?
Thanks in advance,
JR

Answer 1

Hi all,
I have a page with a dataTable that holds information about sales items. On the first visit to the page, the table is displayed normally and sorted by price. It takes a Result as its collection so any sorting is done in SQL. I want to support grouping the items by quantity as well so I used the t:dataTable component and specified a groupBy column. Outside of the table, I have an h:selectBooleanCheckbox that has a value of myBean.groupByQuantity, a valueChangeListener, and an onchange="this.form.submit()". The groupByQuantity boolean is also used in the t:column as the groupBy value. The value change listener checks the value of the groupByQuantity boolean and runs an appropriate query (to order by price or quantity).
Some relevant code:
<t:dataTable value="#{myBean.items}" var="item" groupByStyle="groups">
   <t:column>
    <t:column groupBy="#{myBean.groupByQuantity}">
       <h:outputText value="#{item.quantity}"/>
    </t:column>
</t:dataTable>
<h:selectBooleanCheckbox value="#{myBean.groupByQuantity}"
valueChangeListener="#{myBean.processValueChangeEvent}"
onclick="this.form.submit()"/>In the MyBean.java
public class MyBean{
private boolean groupByQuantity = false;
//getters and setters for groupByQuantity
public void processValueChangeEvent(ValueChangeEvent vce){
   if (!groupByQuantity){
     //run SQL to order by quantity
   }else{
     //run SQL to order by price
public String goBackToList(){
   //run SQL to order by price
   groupByQuantity = false;
}When using the checkbox to toggle the value of groupByQuantity, the code acts as expected (except for the fact that it seems as if the checkbox is submitting the opposite value as it should which is why the two have to be reversed). However, if a user leaves the page and comes back using the goBackToList method, the checkbox keeps whatever state it was in when the application navigated away from the page even though I explicitly set the value to false and secondly, if the value was true then the application runs the query to order by price but the group by style is being displayed but if it is false, the query to run the order by quantity is run and the group by style is not displayed.
Having this information, I can see two problems but do not understand why they are happening. The first is that when I navigate to the page, the valueChangeListener event is being called even though I have not touched the checkbox. This must be happening because that method is the only place where there is a query to order by quantity. The other problem is that the value that is getting submitted to the backing bean and the value that is being reflected by the checkbox and groupBy attributes are not the same value. Has anyone had a similar problem? Does anyone have any advice on how to fix this?
Thanks in advance,
JR