Is SelectableDataModel mandatory on ; how do I implement it

Question

Is it mandatory create a class that implements SelectableDataModel when I want to use selection property on my <p:dataTable>? If yes, how can I "link" my dataTable with a class that implements SelectableDataModel?

Answer 1

No, that's not necessary. You can just specify the rowKey attribute so that <p:dataTable> can figure the unique identifier of the row without the need for SelectableDataModel.

<p:dataTable value="#{bean.items}" var="item" rowKey="#{item.id}" ...>

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For the case you're interested, or need to, here's how you should implement it:

@ManagedBean
@ViewScoped
public class Bean implements Serializable {

    private List<Item> items;
    private ItemDataModel itemModel;

    public Bean() {
        items = itemService.list();
        itemModel = new ItemDataModel(items);
    }

    // ...
}

Where the ItemDataModel look like this:

public class ItemDataModel extends ListDataModel<Item> implements SelectableDataModel<Item> {  

    public ItemDataModel() {
        // Default c'tor, keep alive.
    }

    public ItemDataModel(List<Item> data) {
        super(data);
    }

    @Override
    public Item getRowData(String rowKey) {
        List<Item> items = (List<Item>) getWrappedData();

        for (Item item : items) {
            if (item.getId().equals(rowKey)) {
                return item;
            }
        }

        return null;
    }

    @Override
    public Object getRowKey(Item item) {
        return item.getId();
    }

}

Finally use itemModel instead of items as <p:dataTable value>.

<p:dataTable value="#{bean.itemModel}" var="item" ... />