Can't sort celltable column

Question

I want to sort celltable column, have written so far this, but it doesn't seem to be working, i did it all like in gwt showcase with celltable column sorting:

ListHandler<M> sort;

public View() {

    getM(0,m);
    createM();
}
void createM() {

    Column<M, String> firstColumn = new Column<M, String>(
            new TextCell()) {

        @Override
        public String getValue(M object) {
            return object.getName();
        }

    };

    table.addColumn(firstColumn,"Name");
    firstColumn.setSortable(true);
    sort.setComparator(firstColumn, new Comparator<M>() {

        @Override
        public int compare(M m1, M m2) {

            return m1.getName().compareTo(m2.getName());
        }
    });

    void getM(int dataID, M m) {
    final ListDataProvider<M> listProvider = new ListDataProvider<M>();
    listProvider.addDataDisplay(table);
    listProvider.refresh();
    final List<M> mList = listProvider.getList();
    sort = new ListHandler<M>(mList);



    AsyncCallback<List<M>> callback = new AsyncCallback<List<M>>() {

        @Override
        public void onFailure(Throwable caught) {
            // TODO Auto-generated method stub
        }

        @Override
        public void onSuccess(final List<M> result) {

            for (final M m : result) {

                mList.add(m);

            }

            table.addColumnSortHandler(sort);

        }

    };


        rpcService.getDataSource(dataID, m, callback);

any suggestion, what is wrong here? How can i solve this?

i moved my code from getM() into createM() like:

void createM() {
final ListDataProvider<M> listProvider = new ListDataProvider<M>();
    listProvider.addDataDisplay(table);
    listProvider.refresh();
    final List<M> mList = listProvider.getList();
    sort = new ListHandler<M>(mList);
        Column<M, String> firstColumn = new Column<M, String>(
                new TextCell()) {

        @Override
        public String getValue(M object) {
            return object.getName();
        }

    };

    table.addColumn(firstColumn,"Name");
    firstColumn.setSortable(true);
    sort.setComparator(firstColumn, new Comparator<M>() {

        @Override
        public int compare(M m1, M m2) {

            return m1.getName().compareTo(m2.getName());
        }
    });

and it sort the column, but if i choose the next data to show in column it will be added to the existing items in column, can anyone point me why it is so?

Answer 1

The first example is not working because you re-initialize your sort object:

sort = new ListHandler<M>(mList); 

This removes all settings from sort.

In the second example, you need to call

mList.clear();

before you add new items to this list. Also, move

table.addColumnSortHandler(sort);

from the callback to your create method. There is no need to call it every time you add data.