Build a JSON tree from materialized paths

Question

I\'m planning on using materialized paths in MongoDB to represent a tree and need to convert the materialized paths back into a JSON tree.

ex. // Materialized path

Answer 1

var Comment = new Schema({
    date      : {
        type        : Date,
        default     : Date.now
    },
    event: ObjectId,
    body      : String,
    pathComment  : String,
    user: Array
})
Comment.virtual('level').get(function() {
    return this.pathComment.split(',').length;
});

Comment.find({event: event.id}).sort({pathComment:1}).exec(function(err, comment){

            var collectComment = function(comment){
                return  {
                    body: comment.body,
                    event: comment.event,
                    pathComment: comment.pathComment,
                    id: comment._id,
                    level: comment.level,
                    user: comment.user[0],
                    date: comment.date,
                    comments: []
                };

            }
            var tplComment = [];

            var createChildComment = function(comment, currentNode, level){

                if(level==1){
                    comment.push(collectComment(currentNode));
                }else{
                    createChildComment(comment[comment.length-1]['comments'], currentNode,level-1);
                }
                return;

            }

            for(var k in comment){
               createChildComment(tplComment, comment[k],comment[k].level);
            }
});