Making tree expanded by default

[reemokada]

I'm trying to make my tree grid expanded after data load. I initialized my_tree but when I try to call $scope.my_tree.expand_all() I got the error message undefined object regarding my_tree.
I setted the expand_level to one and it works fine, but I need to show my tree expanded and not collapsed at the beginning.
Did any one have a solution for my problem?

[urosgogic]

It works like this:

vm.treeControl = {};
$timeout(function () {
     vm.treeControl.expand_all();
});