Question

I have a page where I have a static list containing the list of products which are again grouped into product groups.I have a toggle button in the JSP page which shuffles between the enabled and disabled products .Code for my toggle button is as follows

 <h:commandButton value="retrieve"  image="#{displayProductsBean.productsToggleImage}" actionListener="#{displayProductsBean.fetchProductsBasedOnStatus}">
     <c:choose>
      <c:when test="${displayProductsBean.productFetchCriteria=='0'}">
        <f:attribute name="buttonSelected" value="1" />
      </c:when>
      <c:otherwise>
        <f:attribute name="buttonSelected" value="0" />
      </c:otherwise>
    </c:choose>

    </h:commandButton>

Now in the managed bean I am able to get the value of the button selected and have logic to retrieve either enabled or disabled products
But I don’t know how would I get back to the same page and also I don’t want the list to be reloaded again from the DB.Code in my bean class is as follows

public void fetchProductsBasedOnStatus(ActionEvent event)
    {
        System.out.println("The fetchProductsBasedOnStatus in bean is called"); 
        String selected = (String) event.getComponent().getAttributes().get("buttonSelected");
        System.out.println("The value of toggle button is"+selected);
        setProductFetchCriteria(Integer.parseInt(selected));
        System.out.println("The value of toggle button is"+this.toString());

    }

Somebody please help me resolve this …..

Answer 1

But I don’t know how would I get back to the same page

Just return null or void in action method.

and also I don’t want the list to be reloaded again from the DB

Just don’t do that? If you keep the bean in the view scope and load the lists in the (post)constructor, then the same lists will be kept as long as the enduser is interacting with the same view. You should only not use JSTL tags as it breaks the view scope.

Your code can be simplified as follows:

<h:commandButton value="retrieve" image="#{bean.showDisabledProducts ? 'enabled' : 'disabled'}.png" action="#{bean.toggle}">
    <f:ajax render="@form" />
</h:commandButton>

<h:dataTable value="#{bean.products}" ...>
    ...
</h:dataTable>

with

@ManagedBean
@ViewScoped
public class Bean {

    private boolean showDisabledProducts;
    private List<Product> enabledProducts;
    private List<Product> disabledProducts;

    @EJB
    private ProductService service;

    @PostConstruct
    public void init() {
        enabledProducts = service.listEnabledProducts();
        disabledProducts = service.listDisabledProducts();
    }

    public void toggle() {
        showDisabledProducts = !showDisabledProducts;
    }

    public List<Product> getProducts() {
        return showDisabledProducts ? disabledProducts : enabledProducts;
    }

    public boolean isShowDisabledProducts() {
        return showDisabledProducts;
    }

}