CommandLink ActionListeners in DataTable

[Jack J. Jackson]

I'm using Sun RI 1.1_01 and MyFaces Tomahawk 1.1.1. Inside a DataTable, I have a CommandLink that appears on each row of data. The CommandLink has an ActionListener bound to a method on a session-scoped bean. Each row has the same client Id.

I just discovered that the ActionListener is fired for every row in the data table; i.e. if there are 100 rows, the actionListener method is invoked 100 times. I'm not sure why this would ever be useful behavior; it certainly isn't for my application.

Why does the actionListener event get fired for each row in the table? Is it because each row has the same id?

I suspect I've configured something incorrectly and would appreciate being steered back on course.

Thanks.

[Jack J. Jackson]

I'm adding more info to my original post. The following are the artifacts needed to illustrate what I'm talking about:

- faces-config.xml entry

<managed-bean>
  <managed-bean-name>simpleItemContainer</managed-bean-name>
  <managed-bean-class>mypackage.SimpleItemContainer</managed-bean-class>
  <managed-bean-scope>session</managed-bean-scope>
</managed-bean>

- SimpleItemContainer

public class SimpleItemContainer {
    public List<OrderableItem> itemList;
    private int invocationCount;
    
    public SimpleItemContainer() {
        super();
        init();
    }
    
    /**
     * @return Returns the itemList.
     */
    public List<OrderableItem> getItemList() {
        return itemList;
    }
 
    /**
     * @param itemList The itemList to set.
     */
    public void setItemList(List<OrderableItem> itemList) {
        this.itemList = itemList;
    }
 
    private void init() {
        itemList = new ArrayList<OrderableItem>();
        for(int i = 1; i <= 10; i++) {
            itemList.add(new OrderableItem("Item " + i, i));
        }
    }
    
    public void listener(ActionEvent evt) {
        FacesContext ctx = FacesContext.getCurrentInstance();
        String modelRowStr = (String) ctx.getExternalContext().getRequestParameterMap().get("modelRow");
        int modelRow = Integer.parseInt(modelRowStr);
        
        System.out.println("Event received for modelRow #" + modelRow);
        invocationCount ++;
    }
 
    /**
     * @return Returns the invocationCount.
     */
    public int getInvocationCount() {
        return invocationCount;
    }
 
    /**
     * @param invocationCount The invocationCount to set.
     */
    public void setInvocationCount(int invocationCount) {
        this.invocationCount = invocationCount;
    }
}

- OrderableItem

 
public class OrderableItem {
    private String label;
    private int itemNo;
    
    public OrderableItem() {
        super();
    }
    
    public OrderableItem(String label, int orderno) {
        super();
        
        this.label = label;
    }
 
    /**
     * @return Returns the label.
     */
    public String getLabel() {
        return label;
    }
 
    /**
     * @return Returns the itemNo.
     */
    public int getItemNo() {
        return itemNo;
    }
 
    /**
     * @param itemLabel The label to set.
     */
    public void setLabel(String label) {
        this.label = label;
    }
 
    /**
     * @param itemNo The itemNo to set.
     */
    public void setItemNo(int orderNo) {
        this.itemNo = orderNo;
    }
}
 

- simpleList.jsp form element

<h:form id="itemTableForm">
 <t :D ataTable id="table1" value="#{simpleItemContainer.itemList}" var="item" rowIndexVar="index">
    <h:column id="rowIndexCol">
      <f:facet name="header"><h :o utputText value="Item No"/></f:facet>
      <h :o utputText id="rowindex" value="#{index + 1}" />
    </h:column>
    <h:column id="labelCol">
      <f:facet name="header"><h :o utputText value="Label"/></f:facet>
      <h :o utputText id="pagename" value="#{item.label}" />
    </h:column>
    <h:column id="clickItem">
      <f:facet name="header"><h :o utputText value="Link Col"/></f:facet>
      <h:commandLink actionListener="#{simpleItemContainer.listener}"  value="Click Me!" immediate="true">
         <f :p aram name="modelRow" value="#{index}" />
      </h:commandLink>
    </h:column>
  </t :D ataTable>
</h:form>
<h :o utputText value="Invocation Count = #{simpleItemContainer.invocationCount}" />

When a link in a row is clicked, the actionListener method (simpleItemContainer.listener) is fired 10 times. Here's the output after clicking a link:

Item NoLabelLink Col
1Item 1Click Me!
2Item 2Click Me!
3Item 3Click Me!
4Item 4Click Me!
5Item 5Click Me!
6Item 6Click Me!
7Item 7Click Me!
8Item 8Click Me!
9Item 9Click Me!
10Item 10Click Me!
Invocation Count = 10

What I'd like to have happen is have the actionListener method "consume" the event so it's not broadcast 9 times more than is needed.

Since this issue hasn't been raised, I'm sure I've just misconfigured something. (or am doing this all wrong!)

Thanks for any help.

[ March 15, 2006: Message edited by: Jack J. Jackson ]
[ March 15, 2006: Message edited by: Jack J. Jackson ]

[Jack J. Jackson]

Okay. I found the cause of the problem.

I was using a MyFaces HtmlDataTable, but a Sun RI HtmlCommandLink was enclosed in a row. Apparently unique ids were not being generated for each row, causing every CommandLink's actionListener to be fired when any CommandLink was clicked. When I switched the DataTable back to RI from MyFaces, a unique id is generated for each row's CommandLink.

I wanted to use the MyFaces "rowindex" attribute. Maybe if I used the MyFaces JSF impl, things would work, but I'm mandated to use the Sun JSF RI implementation. Oh well.