Traversing down a notebook tree

gistfile1.js

getTreeData: function() {
    var rootNotebooks = this.get('rootNodes');
    var data = [];
    rootNotebooks.forEach(function(notebook) {
      var currentNotebook = notebook;
      var dataObj = Ember.Object.create({
        'text': currentNotebook.get('title'),
        'state' : {'opened' : false, 'selected' : false },
        'children': []
      });
      dataObj['children'].pushObjects(
        getChildren(currentNotebook, dataObj)
      );
      data.pushObject(dataObj);
    });
    
    function getChildren (currentNotebook, dataObj) {
      if (currentNotebook.get('hasChildren') === true) {
        var subNotebooks = currentNotebook.get('subNotebooks');
        var arr = [];
        subNotebooks.forEach(function(notebook) {
          var newDataObj = Ember.Object.create({
            'text': notebook.get('title'),
            'state' : {'opened' : false, 'selected' : false },
            'children': []
          });
          newDataObj['children'].pushObjects(getChildren(notebook, dataObj));
          arr.pushObject(newDataObj);
        });
        return arr;
      } else {
        return [];
      }
    }
    
    return data;
  }