api.js

exports.updateCollection = function(req, res) {
  Collection.update({ _id: req.params.collection }, req.body, {}, function(err, collection) {
    res.send(collection);
  });
};

collection.js

var mongoose = require('mongoose')
  , Schema = mongoose.Schema
  , ObjectId = Schema.ObjectId;

var collectionSchema = new Schema({
  hall: ObjectId,
  parent: ObjectId,
  position: Number,
  label: String,
  haslayout: { type: Boolean, default: false }
});

module.exports = mongoose.model('Collection', collectionSchema);

req.json

{"haslayout":true,"label":"Basement","hall":"4e36466c976e005003000004","_id":"4e4895a913d9adf5f5000006"}