JSF: Problems adding rows to table with custom method

Question

Since this being my first post, I find it only appropriate to thank the development team for such a huge addition to the application development world. You guys rock. You have cured my Java identity crisis. That being said...
I have been stumped for days. I'm making a simple web cart. I am trying to get two string values (name and price) passed through a custom exposed application module method ran on a backing bean. What I want the exposed VO module to do is, upon receiving the two strings, create a new row on the empty data controlled table I have built to store them. Basically I just need to add rows to a table with my custom managed bean. Most recent version.
I have written a test method to make sure my backing bean and exposed app module impl were working. This test works:
//WORKS
//CartInfo.java   
    public String cb1_action() {
        AppModuleImpl am = new AppModuleImpl();
        am.testMethod();
        return null;       
//AppModuleImp.java
    public void testMethod() {
        System.out.println("WORKS");      
    }I found some code on how to add rows and unfortunately it isn't working out for some reason. Here is what is producing the error "Caused By: java.lang.NullPointerException" :
//DOESN'T WORK IN CUSTOM METHOD BUT WORKS WHEN DRAGGED ON TO THE PAGE AS A COMMAND BUTTON
//CartInfo.java
    public String cb1_action() {
        AppModuleImpl am = new AppModuleImpl();
        am.testMethod("test", "test");
        return null;
//AppModuleImp.java
       public void testMethod(String pName,String pPrice) {
        ViewObjectImpl vo = this.getCartVO1();
        Row r = vo.createRow();
        r.setAttribute("NAME", pName);
        r.setAttribute("PRICE", pPrice);
        vo.insertRow(r);
//The VO attributes for the DC are:
// Name : Type : Alias Name : Entity Usage : Info
NAME : String : NAME : (blank) : Transient
PRICE : String : PRICE : (blank) : TransientSo what I have so far is a table linked to my database. A user can select and click on a product on the row's individual Add button and using a modified selection listener, it returns the values to the backing_bean.
Then what I want it to do is have those variables passed to the other table. I just can't put it together.
Please if there is anyone that could send me in the right direction I would greatly appreciate it!
Thank you,
Jack

Answer 1

if i understand you, you want to call application module method when user clicks on add button on the UI and your table is from VO
so what i can come up for now is:
1) create variable binding from the iterator for both name and price.
2) on your UI action button :
<af:commandButton actionListener="yourbean.addToCart">
<f:attribute name="pName" value ="binding.<created name bind variable>"
<f:attribute name="pPrice" value = "binding.<created price bind variable>"
</af:commandButton>
3) custom Managed Bean:
//yourBean.java
public void addToCart(ActionEvent e){
// get binding here
// use executeWitParams method to send parameter to the function "testMethod" and execute
//AppModuleImp.java
public void testMethod(String pName,String pPrice) {
CardVOImpl vo = this.getCartVO1();
CardVORowImpl r = (CardVORowImpl)vo.createRow();
r.setAttribute("NAME", pName);
r.setAttribute("PRICE", pPrice);
vo.insertRow(r);
Hope this helps...
Let me know if not..
Thanks
Edited by: MavenDev on Oct 30, 2011 8:08 PM