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.google.com/intl/it-IT/webtoolkit/doc/latest/DevGuideUiCellTable.html#columnSorting

The Async Remote sorting sections shows very well how to get sorting into my AsyncDataProvider but… how can I retrieve the name of the column the user wants to sort?

It shows this code: ColumnSortList sortList = table.getColumnSortList();

But how can I get String names from that? I simply want to know “surname” or “soldDate”, the name of the field the column is bound to! Then I will pass it to my rpc service, and use it to sort data server-side query(...).order(<field_name>)

Am I missing something?

UPD: interesting stuff here: http://groups.google.com/group/google-web-toolkit/browse_thread/thread/77a0eaf8086218a6/effb8d3abe69270b#effb8d3abe69270b

Answer 1

You can keep a list of column names ordered as they are in the table:

List<String> columnNames = new ArrayList<String>();

table.addColumn(surnameColumn, "surname");
columnNames.add("surname");

// add the other columns

Then when you need to get the sort column name:

String sortColumnName;
ColumnSortList sortList = table.getColumnSortList();
if (sortList != null && sortList.size() != 0){
     Column <MyEntity, ?> sortColumn = (Column <MyEntity, ?>) 
                                           sortList.get(0).getColumn();
     Integer columnIndex = table.getColumnIndex(sortColumn);
     sortColumnName = columnNames.get(columnIndex);
}

// do your rpc call

*where MyEntity is your data object displayed in the cell table.