Grid data content not properly sync

General
1

Hi,

I’m facing a really weird behavior in using GRID component where I do modify its content.
I’ll explain the flow I follow to reach to this situation:

  1. I create a Grid component and define a BeanItemContainer associated to it.
	BeanItemContainer<Object> conNew = new BeanItemContainer(bean.getClass());
	Grid grdNew = new Grid("New data", conNew);
  1. Add some data to it deleting the previous one.
	public boolean insertNewData(ArrayList<?> data) {
		boolean res = true;
		grdNew.getContainerDataSource().removeAllItems();
		grdNew.getSelectionModel().reset();
		grdNew.refreshAllRows();

	if (data.size() > 0) {
		try {
			for (Object item : data) grdNew.getContainerDataSource().addItem(item);
			grdNew.getSelectionModel().reset();
			grdNew.recalculateColumnWidths();
			grdNew.refreshAllRows();
		} catch (Exception e) {
			res = false;
		}
	} else grdNew.setHeightByRows(1);

	return res;
}
  1. The first time I add data to the Grid, when I select any of the items, I can check that the selected item is properly obtained from
		grdNew.addSelectionListener(new SelectionListener() {
			@Override
			public void select(SelectionEvent event) {
				Set<Object> selEvent = event.getSelected();
			}
		});
  1. If I call again insertNewData(…) method and I select any row from the Grid, what I get in the selection listener are the rows previously selected!
  2. Besides, if instead of retrieve the selected rows from the Grid I get the list of items contained, I get correctly the last loaded into the Grid.

Can anyone explain what is happening?

Thanks in advance,
Martin

2

Sounds like maybe something is getting mixed up in the internal bookkeeping of selected items. Instead of refreshing the existing data, it might be better just to create a whole new Grid from scratch.

-Olli

3

Thanks a lot for your response Olli,

I’ve thought that the command on the Grid

grdNew.getSelectionModel().reset();

would precisely do that: forces a refresh on the selected items. Isn’t that so?
Is there any other way to force the refreshing?

Anyway, I’ll make a test as you propose and I’ll see what happens…

4

The JavaDoc of SelectionModel::reset says:

/**
         * Resets the SelectiomModel to an initial state.
         * <p>
         * Most often this means that the selection state is cleared, but
         * implementations are free to interpret the "initial state" as they
         * wish. Some, for example, may want to keep the first selected item as
         * selected.
         */

…so the actual implementation is left some amount of freedom to do what it wants.

The implementation in MultiSelectionModel just does this:

        /**
         * Resets the selection model.
         * <p>
         * Equivalent to calling {@link #deselectAll()}
         */
        @Override
        public void reset() {
            deselectAll();
        }

so I’m not sure how that will play out. You’d need to investigate how exactly deselect works in that scenario (itemids have changed / selection is not included in itemids any more).

-Olli

-Olli

5

I’ve found a workaround to solve this issue. It’s not very elegant nor efficient but it works:

to get the currently selected items, instead of:

Set<Object> elemSelected = new HashSet<Object>((Collection<? extends Object>) grdNew.getSelectionModel().getSelectedRows());

it can be done:

Set<Object> elemSelected = new HashSet<Object>();
Set<Object> elemTotal = new HashSet<Object>((Collection<? extends Object>) grdNew.getContainerDataSource().getItemIds());
for (Object elem : elemTotal) 
	if (grdNew.getSelectionModel().isSelected(elem)) elemSelected.add(elem);

I do not understand the logic behind this, but at least it works