onReadByIds method
Subclass hook for readByIds, return rows with nulls cells for each id not found.
Implementation
@override
Future<HGrid> onReadByIds(List<HRef> ids) {
var b = HGridBuilder();
b.addCol("id");
for (int i = 0; i < ids.length; ++i) {
b.addRow([ids[i]]);
}
return call("read", b.toGrid());
}