A simple PHP Trait to make Doctrine MongoDB ODM Documents serializable to Array or JSON

1_DocumentSerializer.php

<?php
/**
 * Created by PhpStorm.
 * Author: Anis Ahmad <anisniit@gmail.com>
 * Date: 5/11/14
 * Time: 10:44 PM
 */
namespace Your\CoreBundle\Traits;


trait DocumentSerializer {

    private $_ignoreFields = array();

    /**
     * Convert Doctrine\ODM Document to Array
     *
     * @return array
     */
    function toArray() {
        $document = $this->toStdClass();
        return get_object_vars($document);
    }

    /**
     * Convert Doctrine\ODM Document to Array
     *
     * @return string
     */
    function toJSON() {
        $document = $this->toStdClass();
        return json_encode($document);
    }

    /**
     * Set properties to ignore when serializing
     *
     * @example  $this->setIgnoredFields(array('createdDate', 'secretFlag'));
     *
     * @param array $fields
     */
    function setIgnoredFields(array $fields) {
        $this->_ignoreFields = $fields;
    }

    /**
     * Convert Doctrine\ODM Document to plain simple stdClass
     *
     * @return \stdClass
     */
    function toStdClass()
    {
        $document = new \stdClass();

        foreach($this->findGetters() as $getter) {
            $prop = lcfirst(substr($getter, 3));

            if(! in_array($prop, $this->_ignoreFields)) {
                $value = $this->$getter();
                $document->$prop = $this->formatValue($value);
            }
        }

        return $document;
    }

    private function findGetters()
    {
        $funcs = get_class_methods(get_class($this));
        $getters = array();

        foreach($funcs as $func) {
            if(strpos($func, 'get') === 0) {
                $getters[] = $func;
            }
        }

        return $getters ;
    }

    private function formatValue($value) {

        if(is_scalar($value)) {
            return $value;

        // If the object uses this trait
        } elseif (in_array(__TRAIT__, class_uses(get_class($value)))) {
            return $value->toStdClass();

        // If it's a collection, format each value
        } elseif (is_a($value, 'Doctrine\ODM\MongoDB\PersistentCollection')) {
            $prop = array();
            foreach($value as $k => $v) {
                $prop[] = $this->formatValue($v);
            }
            return $prop;

        // If it's a Date, convert to unix timestamp
        } else if(is_a($value, 'DateTime')) {
            return $value->getTimestamp();

        // Otherwise leave a note that this type is not formatted
        // So that I can add formatting for this missed class
        } else {
            return 'Not formatted in DocumentSerializer: '. get_class($value);
        }
    }
}

2_Document.php

<?php
namespace Your\CoreBundle\Document;

// use ... (other classes)
use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;
use Your\CoreBundle\Traits\DocumentSerializer;

/**
 * @ODM\Document(collection="reports")
 */
class Report
{
    use DocumentSerializer;
    // NOTE: You have to use this trait to all it's embedded documents too
    
    public function __construct() {
        // You can hide some fields in serialized format
        $this->setIgnoredFields(array('createdDate', 'secretFlag'));
    }
    
    // ... Your as usual document code
}

3_SerializationExample.php

<?php
// Assuming in a Symfony2 Controller
// If you're not, then make your DocmentManager as you want
$dm = $this->get('doctrine_mongodb')->getManager();
$report = $dm->getRepository('YourCoreBundle:Report')->find($id);

// Will return simple PHP array
$docArray = $report->toArray();

// Will return JSON string
$docJSON = $report->toJSON();

4_toJSONExample.js

// today and yesterday has Embedded Documents
// Dates are converting to php timestamp
{
  id: "536fe7778ead0e5500d63b00",
  today: [
    {
      id: "536fe7778ead0e5500d63b01",
      title: "The first task",
      done: false
    },
    {
      id: "536fe7778ead0e5500d63b02",
      title: "The second task",
      done: false
    }
  ],
  yesterday: [
    {
      id: "536fe7778ead0e5500d63b03",
      title: "I did it yesterday",
      done: true
    }
  ],
  created: 1399842679,
  updated: 1399842679
}

Having issues with embedded documents variables getting set to null. thoughts?