Mongoose, a recursive population hierarchy

Question

Mongoose, a recursive population hierarchy

I have a fairly large data set, where each element has a field hierarchywith an attribute children, which is an array of links to other elements. I want to get all the top parent elements and fill them up to all sheets.

Item = new Schema({
  ...,
  hierarchy: {
    children: [{
      type: mongoose.Schema,
      ref: 'Item'
    }],
  ...
})

Filling only fills one level and does not continue through the tree. I also tried mongoose-deep-populate , but couldn't get it to work. Can I write a recursive function to fill in all the fields? One of my ideas was to write something like this:

items = _.map(items, function(item){
  return populateChildren(item);
});

function populateChildren(item){
    if(item.hierarchy && item.hierarchy.children && item.hierarchy.children.length > 0){
        item.hierarchy.children = _.map(item.hierarchy.children, function(child){
            console.log(count++, child);
            return Item.findById(child).exec(function(err, child){
                return populateChildren(child);
            })
        });
    }
    return item;
}