add dynamic row content to vaadin grid - vaadin-grid

Question

In vaadin7, I used GeneratedPropertyContainer to do this, eg adding row number:
wrappedContainer = new GeneratedPropertyContainer(_container);
wrappedContainer.addGeneratedProperty("#",
new PropertyValueGenerator<Integer>() {
#Override
public Integer getValue(Item item, Object itemId, Object propertyId) {
return (int) _container.indexOfId(itemId) + 1;
}
#Override
public Class<Integer> getType() {
return java.lang.Integer.class;
}
}
);
setContainerDataSource(wrappedContainer);
In vaadin8, since GeneratedPropertyContainer is deprecated, I tried to do like this:
grid.addColumn((v)->((List)_container.getData().getItems()).indexOf(v)+1);
But the index is static, when I sort the rows ascending and descending, the row number is moving too.
What I need is the first row is row number 1 and the last row is row number N, no matter how I sort the rows.
Thanks.

Answer 1

Unfortunately, as far as I can tell there is no simple solution out of the box. However, you can do like the following code:
Grid<MyBean> grid = new Grid<>();
grid.setDataProvider(new RowIndexDataProviderWrapper<>(DataProvider.ofItems(new MyBean("Item 1"), new MyBean("Item 2"), new MyBean("Item 3"))));
grid.addColumn(MyBean::getRowIndex).setCaption("#");
grid.addColumn(MyBean::getName).setCaption("Name");
public interface RowIndexAware {
void setRowIndex(int rowIndex);
int getRowIndex();
}
public class MyBean implements RowIndexAware {
// implement the interface (e.g. store row index in field)
// and add your bean properties
}
public class RowIndexDataProviderWrapper<T extends RowIndexAware, F> implements DataProvider<T, F> {
private DataProvider<T, F> wrapped;
public RowIndexDataProviderWrapper(DataProvider<T, F> wrapped) {
this.wrapped = wrapped;
}
// delegate all methods to be implemented for DataProvider interface
// to wrapped DataProvider with the exception of "fetch":
#Override
public Stream<T> fetch(Query<T, F> query) {
List<T> result = wrapped.fetch(query).collect(Collectors.toCollection(ArrayList::new));
for (int i = 0; i < result.size(); i++) {
result.get(i).setRowIndex(query.getOffset() + i);
}
return result.stream();
}
}
The idea is to get the row index when rows are fetched within the DataProvider and to store them in your bean.