Question

In my code, I have the following objects to implement a shopping cart:

public class CartItem {
    ...
    public int id;
    public int quantity;
    ...
}

public class Partner {
    ...
    public List<CartItem> listOfItems;
    ...
}

public class Cart implements Serializable {
    ...
    private List<Partner> listOfPartners;
    ...
}

In the ViewCart.xhtml page, I list the items as following:

...
<ui:repeat value="#{cartManagedBean.cart.listOfPartners}" var="p">
    <ui:repeat value="#{p.listOfItems}" var="i">
        <h:form>
            ...
            <h:inputText size="3" value="#{i.quantity}" />

            <h:commandButton value="Update" />
            ...
        </h:form>
    </ui:repeat>
</ui:repeat>
...

And this is my ManagedBean:

@ManagedBean
@SessionScoped
public class CartManagedBean {
    ...
    private Cart cart;
    ...
}

All the getters and setters methods are properly done. Hence, I expected that when I click the update button, the quantity of the corresponding Item would be updated. However, when I test the function, only the last item in the list can be updated.

I’d be very grateful if someone could give me an advice on how I should tackle this problem.

UPDATE: I managed to make it work by replacing ui:repeat with h:dataTable. I think my knowledge of ui:repeat should be wrong somewhere. When I was using ui:repeat, I saw that the HTML generated was something like:

<form>
    ...
    <input type="submit" id="jdt:51;jdt52" />
    ...
</form>
<form>
    ...
    <input type="submit" id="jdt:51;jdt52" />
    ...
</form>

In other words, all the Items were generated with the same ID. I even tried to make the ID of the input for quantity unique by appending the unique ID of each item to the ID of the input as following:

<h:inputText id="quantity#{i.id}" size="3" value="#{i.quantity}" />

However, in the HTML result, I saw that the ID was something like:

<form>
    ...
    <input type="submit" id="jdt:51;jdt52;quantity203" />
    ...
</form>
<form>
    ...
    <input type="submit" id="jdt:51;jdt52;quantity203" />
    ...
</form>

In other words, the ID of the 1st Item was repeated for all subsequent items. Even though I haven’t fully understood how variables are updated with new values, I think this is the reason why only the last item can be updated.

I’d be very grateful if someone could explain this further for me so that I won’t make the same mistake again =).

Answer 1

You seem to be using Mojarra. The <ui:repeat> is totally broken in Mojarra. I can reproduce your problem even on the latest Mojarra 2.1.4. It however works 100% when using MyFaces 2.1.3. I’ve reported it to the Mojarra guys as issue 2243.

You have 3 options:

• Replace Mojarra by MyFaces.
• Use <c:forEach> instead of <ui:repeat>. This only works if the <c:forEach> is not by itself inside some UIData component.
• Use an UIData component instead of <ui:repeat>.