We are tryping to use igpivotgrid with olap xmla data source and want to have expand and collapse functionality on button click.

For this, we are using below code

 <input type="button" onclick="expand()" value="Expand" />

function expand() {
var tuplesCount, membersCount;
for (var x = 0; x < dataSource.result().axes().count() ; x++) {
tuplesCount = dataSource.result().axes().item(x).tuples().count();
for (var i = 0; i < tuplesCount; i++) {
membersCount = dataSource.result().axes().item(x).tuples().item(i).members().count();
for (var j = 0; j < membersCount; j++) {
if (dataSource.result().axes().item(x).tuples().item(i).members().item(j).isExpandable()) {
dataSource.expandTupleMember(dataSource.result().axes().item(x).name(), i, j);
dataSource.update();
}
}
}
}
}

After adding a meaure and a dimension, on first "Expand" button click, it throws an error in browser console "TypeError: Cannot read property 'createAxis' of null(…)"