<?php

/**
 * XML document manipulations library.
 *
 * @author     Time.ly Network Inc.
 * @since      2.0
 *
 * @package    AI1EC
 * @subpackage AI1EC.Xml
 */
class Ai1ec_XML_Builder {

        /**
         * Serializes given data (array, object, etc.) and generates an XML
         * document from it. If $wrap_json is true, simply serializes the data as
         * JSON and generates a simple XML wrapper around it.
         *
         * Function adapted from
         * http://www.sean-barton.co.uk/2009/03/turning-an-array-or-object-into-xml-using-php/
         *
         * @param  mixed    $data       Data to serialize.
         * @param  boolean  $wrap_json  Whether to serialize data in JSON format.
         * @param  string   $node_block Name of root-level XML element.
         * @param  string   $node_name  Name of XML element to wrap around ordinal array elements.
         * @return string               Valid XML document.
         */
        public static function serialize_to_xml(
            $data, $wrap_json = true, $node_block = 'data', $node_name = 'node'
        ) {
            $xml = '<?xml version="1.0" encoding="UTF-8" ?>';

            $xml .= '<' . $node_block . '>';

            if ( $wrap_json ) {
                $xml .= '<![CDATA[' . json_encode( $data ) . ']]>';
            }
            else {
                $xml .= self::_generate_xml_from_value( $data, $node_name );
            }

            $xml .= '</' . $node_block . '>';

            return $xml;
        }

        /**
         * Serializes $value into an XML document fragment.
         *
         * Function adapted from
         * http://www.sean-barton.co.uk/2009/03/turning-an-array-or-object-into-xml-using-php/
         *
         * @param  mixed    $array      Value to serialize.
         * @param  string   $node_name  Name of XML element to wrap around ordinal array elements.
         * @return string               Valid XML document.
         */
        private static function _generate_xml_from_value( $value, $node_name ) {
            if ( is_array( $value ) || is_object( $value ) ) {
                $xml = '';

                foreach ( $value as $key => $value ) {
                    if ( is_numeric( $key ) ) {
                        $key = $node_name;
                    }

                    $xml .= '<' . $key . '>' .
                        self::_generate_xml_from_value( $value, $node_name ) .
                        '</' . $key . '>';
                }
            }
            else {
                $xml = htmlspecialchars( $value, ENT_QUOTES );
            }

            return $xml;
        }
}