The purpose of size() is to give the DataView an idea of how many pages there will be, so this really won't work. You should fetch size in a separate query as the number of orders total over all pages, and cache that.
best, jim On 5/29/07, V. Jenks <[EMAIL PROTECTED]> wrote: > > I'm trying to use a provider class for a DataView so I can do paging/sorting, > etc. It looks like this: > > ************************************************ > public class OrderProvider implements IDataProvider > { > private transient List<Order> orders; > > public OrderProvider() > { > } > > public Iterator iterator(int first, int count) > { > this.orders = > WicketHelper.<List<Order>>getDetachedModelObject( > OrderProxy.getAll(first, first + count)); > > return this.orders.iterator(); > } > > public IModel model(Object model) > { > return WicketHelper.getDetachedModel(model); > } > > public int size() > { > return this.orders.size(); > } > } > ************************************************ > > I thought this would work but it looks like size() is called first, since I > get a NPE: > > ************************************************ > Caused by: java.lang.NullPointerException > at com.myapp.provider.OrderProvider.size(OrderProvider.java:36) > ************************************************ > > It works if size() makes a call to the database to get a count of > records...but I'm trying to use a global field to prevent that data call. > > Any suggestions? > -- > View this message in context: > http://www.nabble.com/Chicken-and-egg-w--Data-Provider-tf3834369.html#a10855464 > Sent from the Wicket - User mailing list archive at Nabble.com. > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > Wicket-user mailing list > Wicket-user@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wicket-user > ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Wicket-user mailing list Wicket-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wicket-user