Node Mongoose attr_accessible - how I make my sub documents have public attributes.

publicProperties.js

/* this method is async */
UserSchema.methods.toPublic = function(done) {
  if(typeof done !== "function") {
    return undefined;
  }

  // this is a shared object, so beware of concurrency issues
  var publicObj = {
    _id: this.id,
    email: this.email,
    firstName: this.firstName,
    lastName: this.lastName,
    username: this.username
  };

  // add all the functions used to map models here
  var toMap = [];

  // map the posts model
  if(this.profile && this.profile.posts) {
    toMap.push(function(publicObj, callback) {
      async.map(this.profile.posts || [], function(post, cb) {
        post.toPublic(function(err, obj) {
          if(err) {
            return cb(err, null)
          }
          cb(null, obj);
        });
      }, function(err, posts) {
        if(err) return callback(err);
        // add posts to the public object to be returned
        publicObj.profile = {
          posts: posts
        }
        callback(null, publicObj);
      });
    }.bind(this, publicObj));
  }

  // this will run each of the model map functions in parallel
  async.parallel(toMap, function(err, results) {
    if(err) return console.log(err);
    done(null, publicObj);
  });
}; // end toPublic method