Updated PHP VDF code to support arrays of maps.

test.php

<?php

error_reporting(-1);
ini_set('display_errors', 'On');


$test_data = <<<TEST_DATA
"treasure_chest_59_trappers_pelt"
{
    "Crescent" "1"
    "Rightful Heir" "1"
    "Tribal Terror" "1"
    "Vestments of the Infinite Waves" "1"
    "additional_drop"
    {
        "chance" "1"
        "item" "The Iron Claw"
    }
    "additional_drop"
    {
        "chance" "1"
        "item" "Jin and Yin Fox Spirits"
    }
    "additional_drop"
    {
        "chance" "1"
        "loot_list" "treasure_chest_58_59_unusual_courier"
    }
}
TEST_DATA;


include("vdf.php");

$kv_data = new KeyValues("DATER");


header("content-type: application/json");
echo json_encode($kv_data->load($test_data));

vdf.php

<?php
/**
 * Tree-based Valve KeyValues parser
 * Updated 2014-09-03 by Rob Jackson to support arrays of maps.
 *
 * @author GameConnect
 * @author Rob Jackson <[email protected]>
 *
 * @copyright (C)2007-2013 GameConnect.net.  All rights reserved.
 * @link http://www.sourcebans.net
 *
 * @package sourcebans.components
 * @since 2.0
 */
class KeyValues
{
        /**
         * @var string Root section name
         */
        protected $_name;


        /**
         * Constructor
         *
         * @param string $name Root section name
         * @param array $data Optional key values data
         */
        public function __construct($name = null, $data = null)
        {
                $this->_name = $name;

                if(is_array($data))
                {
                        parent::__construct($data);
                }
        }

        /**
         * Returns a property value
         *
         * @param string $name The property name
         * @return mixed The property value
         */
        public function __get($name)
        {
                switch($name)
                {
                        case 'name':
                                return $this->_name;
                }
        }

        /**
         * Blocks setting property values
         *
         * @param string $name The property name
         * @param string $value The property value
         */
        public function __set($name, $value) {}

        /**
         * Returns a string representation of the data
         *
         * @return string The string representation of the data
         */
        public function __toString()
        {
                $ret  = $this->name . "\n{\n";
                $ret .= $this->_build(parent::getArrayCopy());
                $ret .= '}';

                return $ret;
        }


        /**
         * Loads key values data from a string or file
         *
         * @param string $string String or file to load
         */
        public function load($string)
        {
                if(is_readable($string))
                {
                        $string = file_get_contents($string);
                }

                // Use token_get_all() to easily ignore comments and whitespace
                $tokens = token_get_all("<?php\n" . $string . "\n?>");
                $data   = $this->_parse($tokens);
                // Strip root section
                $data   = reset($data);

                return $data;
        }

        /**
         * Saves key values data to file
         *
         * @param string $file File to save to
         * @return boolean Whether saving was successful
         */
        public function save($file)
        {
                if(($fp = fopen($file, 'w+')) === false)
                        return false;

                fwrite($fp, $this);
                fclose($fp);
                return true;
        }

        /**
         * Serializes key values data and root section name
         */
        public function serialize()
        {
                return serialize(array(
                        'data' => parent::serialize(),
                        'name' => $this->_name,
                ));
        }

        /**
         * Returns an array representation of the data
         *
         * @return array The array representation of the data
         */
        public function toArray()
        {
                return parent::getArrayCopy();
        }

        /**
         * Unserializes key values data and root section name
         */
        public function unserialize($data)
        {
                $data        = unserialize($data);
                $this->_name = $data['name'];

                parent::unserialize($data['data']);
        }


        /**
         * Recursively builds key values string
         *
         * @param array $data Key values data to write
         * @param integer $level Optional level to use for indenting
         */
        private function _build($data, $level = null)
        {
                // Default level to 0
                if(!is_numeric($level))
                {
                        $level = 0;
                }

                $indent = str_repeat("\t", $level + 1);
                $ret    = '';

                foreach($data as $key => $value)
                {
                        if(is_array($value))
                        {
                                reset($value);
                                // If array is numerical, write key sub-value pairs
                                if(is_int(key($value)))
                                {
                                        foreach($value as $sub_value)
                                        {
                                                $ret .= sprintf("%s\"%s\"\t\"%s\"\n",
                                                        $indent, $key, $sub_value);
                                        }
                                }
                                // Otherwise, recursively write section
                                else
                                {
                                        $ret .= sprintf("%s\"%s\"\n%s{\n",
                                                $indent, $key, $indent);

                                        $ret .= $this->_build($value, $level + 1);
                                        $ret .= $indent . "}\n";
                                }
                        }
                        // Write key value pair
                        else
                        {
                                $ret .= sprintf("%s\"%s\"\t\"%s\"\n",
                                        $indent, $key, $value);
                        }
                }

                return $ret;
        }

        // Returns whether the given array is associative (has keys) or sequential.
        private function is_assoc($array) {
            return (bool)count(array_filter(array_keys($array), 'is_string'));
        }

        /**
         * Recursively parses key values data from tokens
         *
         * @param array $tokens Tokens received from token_get_all()
         */
        private function _parse(&$tokens)
        {
                $data = array();
                $key  = null;

                // Use each() so the array cursor is also advanced
                // when the function is called recursively
                while(list(, $token) = each($tokens))
                {
                        // New section
                        if($token == '{')
                        {
                            // Recursively parse section

                            if (array_key_exists($key, $data)) {
                                // If key is already in data then we have an array of values
                                if (!is_array($data[$key]) || $this->is_assoc($data[$key])) {
                                    // If the existing data is not a sequential array we need to convert it to an array.
                                    $data[$key] = array($data[$key]);
                                }

                                // Append data to array
                                $data[$key][] = $this->_parse($tokens);

                            }
                            else {
                                // If the key isn't in the data, add it!
                                $data[$key] = $this->_parse($tokens);
                            }
                            $key        = null;
                        }
                        // End section
                        else if($token == '}')
                        {
                                return $data;
                        }
                        // Key or value
                        else
                        {
                                $value = $token[1];
                                switch($token[0])
                                {
                                        case T_CONSTANT_ENCAPSED_STRING:
                                                // Strip surrounding quotes, then parse as a string
                                                $value = substr($value, 1, -1);
                                        case T_STRING:
                                                // If key is not set, store
                                                if(is_null($key))
                                                {
                                                        $key = $value;
                                                }
                                                // Otherwise, it's a key value pair
                                                else
                                                {
                                                        // If value is already set, treat as an array
                                                        // to allow multiple values per key
                                                        if(isset($data[$key]))
                                                        {
                                                                // If value is not an array, cast
                                                                if(!is_array($data[$key]))
                                                                {
                                                                        $data[$key] = (array)$data[$key];
                                                                }

                                                                // Add value to array
                                                                $data[$key][] = $value;
                                                        }
                                                        // Otherwise, store key value pair
                                                        else
                                                        {
                                                                $data[$key] = $value;
                                                        }

                                                        $key = null;
                                                }
                                }
                        }
                }

                return $data;
        }
}