Skip processing of input components inside p:dataTable when a button is pressed which only needs to get selected rows

Question

I have prepared just a simple example of shopping basket for the demonstration purpose only.

The XHTML page:

<p:dataTable id="cartDataTable" value="#{testManagedBean.qtyList}"
             var="cart"
             selection="#{testManagedBean.selectedQtyList}"
             rowKey="#{cart.id}">

    <p:column selectionMode="multiple" />

    <p:column>
        <h:outputText value="#{cart.id}"/>
    </p:column>

    <p:column>
        <p:inputText value="#{cart.qty}"/>
    </p:column>
</p:dataTable>

<p:commandButton value="Delete" process="@this cartDataTable"
                 actionListener="#{testManagedBean.delete}"/>

The managed bean:

@ManagedBean
@SessionScoped
public final class TestManagedBean implements Serializable
{
    private List<Cart>qtyList; //Getter only.
    private List<Cart>selectedQtyList; //Getter and setter.
    private static final long serialVersionUID = 1L;

    @PostConstruct
    public void init()
    {
        qtyList=new ArrayList<>();
        qtyList.add(new Cart(1, 1));
        qtyList.add(new Cart(2, 1));
        qtyList.add(new Cart(3, 2));
        qtyList.add(new Cart(4, 1));
        qtyList.add(new Cart(5, 3));
    }

    public void delete()
    {
        for(Cart cart:selectedQtyList) {
            System.out.println(cart.getId()+" : "+cart.getQty());
        }

        System.out.println("Perform deletion somehow.");
    }
}

This is a session scoped JSF managed bean holding a shopping cart. The class Cart is quite intuitive with only two properties of type Integer namely id and qty and a parameterized constructor.

When the given delete button is clicked, we need to set the selected rows to be deleted to the backing bean.

To set the selected rows, the process attribute of <p:commandButton> is set to @this and cartDataTable which sets the selected rows to the bean's property selectedQtyList, when this button is pressed.

Since this a session scoped bean, if a user unknowing modifies the quantity in the cart in any row/s prior to pressing the delete button then, new value/s of quantity is/are set to list qtyList.

This should happen only when updating the cart but certainly must not happen anymore while deleting row/s.

In real application, deletion is done in a separate view scoped bean.

If the process attribute of <p:commandButton> is set to @this only (i.e process="@this" removing cartDataTable from this attribute) then, selected rows are not set to the managed bean property selectedQtyList.

How to proceed with this?

If I understand it correctly you can give your inputText a styleClass of your own choice, and then omit components with this class in process="" with a jQuery selector. See BalusC's answer here: http://stackoverflow.com/questions/12614882/how-to-exclude-child-component-in-ajax-update-of-a-parent-component/ — Jaqen H'ghar, Jul 13 '14 at 18:27
`` is inside ``. It is quite unlikely to make its ids available outside `` to be excluded from being processed, when `` is clicked. — Tiny, Jul 13 '14 at 18:35
You can use the styleClass attribute and it will work. What is unlikely? — Jaqen H'ghar, Jul 13 '14 at 18:37
This `` `` does not work nor `process="@this cartDataTable @(form :not(.noupdate))"`. — Tiny, Jul 13 '14 at 18:50
What about just process="@(form :not(.noupdate))" as both @this and datatable is in the same form. Otherwise I think you can use any selector: http://api.jquery.com/category/selectors/ — Jaqen H'ghar, Jul 13 '14 at 18:57
`process="@(form :not(.noupdate))"` makes no difference either. — Tiny, Jul 13 '14 at 19:05
Maybe I don't understand the question... What is the problem with having new quantity values set if the item is going to be deleted? — rion18, Jul 16 '14 at 00:18
@rion18 : Then there is no problem, if new values are set for some rows (in the quantity column) and those rows are deleted but it is not necessary. New quantity values may be set for rows which are not selected/marked for deletion (a user may unknowingly change values in `` while deleting rows from the cart) and consequently those rows are not going to be deleted. New values of quantity for such rows will then be reflected from the user session which is intuitively not expected to happen while deleting items from the basket. — Tiny, Jul 16 '14 at 00:33
What would be the best solution in your opinion: if there's a selected item then disable the input, or always let the user change the quantity and ignore those values if and only if the remove button is pressed? — rion18, Jul 16 '14 at 01:10
@rion18 : I cannot determine myself. Anything that functions is sufficient for me. It should not always be the best :) — Tiny, Jul 16 '14 at 03:15

BalusC · Accepted Answer · 2014-07-16T10:24:08.410

As far as I understand, you basically want to prevent <p:inputText value="#{cart.qty}"> from being processed (updating the model value) when the delete button is pressed. Theoretically, it should work to only specify the selection column in the process attribute, but unfortunately <p:dataTable> didn't eat that. Also, immediate="true" on the button won't help as the <p:column selectionMode> doesn't support that.

Your best bet is making sure that rendered attribute of the input field only evaluates true if the delete button is not pressed or when JSF is rendering the response.

<p:inputText ... rendered="#{empty param[delete.clientId] or facesContext.renderResponse}" />
...
<p:commandButton binding="#{delete}" ... />

JSF namely won't process input components which aren't rendered. The bean scope is irrelevant in this case.

Skip processing of input components inside p:dataTable when a button is pressed which only needs to get selected rows

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