Photo Model & Service

photo.model.js

'use strict';

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

var PhotoSchema = new Schema({
  type: {
    type: String,
    enum: ['png', 'jpeg', 'gif']
  },
  width: Number,
  height: Number,
  size: Number,
  image: String,
  ref: {
    collection: String,
    id: Schema.Types.ObjectId
  },
  created_at: {
    type: Date,
    default: Date.now,
    index: true
  }
});

module.exports = mongoose.model('Photo', PhotoSchema);

photo.service.js

'use strict';

var Bluebird = require('bluebird'),
    _ = require('lodash'),
    Photo = localrequire.model('photo');

exports.create = function(contents) {
  _.forOwn(contents, function(value, key) {
    if (!_.contains(['type', 'width', 'height', 'size', 'image', 'ref'], key)) delete contents[key];
  });

  var deferred = Bluebird.defer();

  new Photo(contents).save(function(err, photo) {
    if (err) return deferred.reject(err);

    deferred.resolve(photo);
  });

  return deferred.promise;
};

exports.read = function(id) {
  var deferred = Bluebird.defer();

  Photo.findById(id).exec(function(err, photo) {
    if (err) {
      if (err.name === 'CastError' && err.type === 'ObjectId')
        return deferred.reject(Errors.PhotoNotFound(id));
      else
        return deferred.reject(err);
    }

    if (!photo) return deferred.reject(Errors.PhotoNotFound(id));

    deferred.resolve(photo);
  });

  return deferred.promise;
};