Question

I have the following code

---

taskDataProvider = new ListDataProvider<TaskHeader>();  
taskDataProvider.addDataDisplay(taskTable);
ListHandler<TaskHeader> columnSortHandler = new ListHandler<TaskHeader>(
            taskDataProvider.getList());
taskTable.addColumnSortHandler(columnSortHandler);

//Some other code that modifies the list in taskDataProvider

---

When I click on the column header the ColumnSortEvent is fired but upon inspection I can see that the list in columnSortHandler is empty. Any modifications made to the taskDataProvider list have not been reflected in columnSortHandler. Am I missing something?

Answer 1

The example here seems to be exactly what you are looking for.
From what you’re showing of your code, I would say you are missing the comparator

columnSortHandler.setComparator(yourColumn,
        new Comparator<TaskHeader>() {
          public int compare(TaskHeader t1, TaskHeader t2) {
            return o1.field1.compareTo(o2.field1);
          }
        });

Also, when adding or removing data to your dataProvider, make sure you do not set a new list but add or remove data instead. Otherwise your dataProvider and listHandler will not be working with the same list ..

Don’t :

taskDataProvider.setList(newList);

Do:

taskDataProvider.getList().add(newItem);