Sorting a CellTable server-side

Question

I\'m currently using a Gwt CellTable, bound to my GAE/Objectify backend via RPC calls.

All right now! :-)

Then I want to sort columns, so I read http://code.goog

Answer 1

A bit late to the party, but here's a more straight-forward solution based off of the current documentation (see section 'ColumnSorting with AsyncDataProvider').

When we're adding our columns we can simply set the dataStoreName:

TextColumn surname = new TextColumn() {
    ...
}
surname.setSortable(true);
surname.setDataStoreName("surname");  // Set the column name
table.getColumnSortList().push(surname);
table.addColumn(surname, "Last Name");  // eg. A different name for the UI

Then we can retrieve the column's dataStoreName later when sorting:

@Override
protected void onRangedChanged(HasData display) {
    ...
    ColumnSortList.ColumnSortInfo info = table.getColumnSortList().get(0);
    String sortColumn = info.getColumn().getDataStoreName();  // Get the column name
    boolean sortIsAscending = info.isAscending();

    rpcService.requestMyData(
        sortColumn,
        sortIsAscending,
        new AsyncCallback>() {...}
    );
    ...
}

Using this method we can pass the column name directly to our RPC method. It even allows us to use a different name (eg. the database column name) than the column name used on the UI/client side.