/application/libraries/Format.php

<?php
/**
 * Format class
 *
 * Help convert between various formats such as XML, JSON, CSV, etc.
 *
 * @author      Phil Sturgeon
 * @license     http://philsturgeon.co.uk/code/dbad-license
 */
class Format {

    // Array to convert
    protected $_data = array();

    // View filename
    protected $_from_type = null;

    /**
     * Returns an instance of the Format object.
     *
     *     echo $this->format->factory(array('foo' => 'bar'))->to_xml();
     *
     * @param   mixed  general date to be converted
     * @param   string  data format the file was provided in
     * @return  Factory
     */
    public function factory($data, $from_type = null)
    {
        // Stupid stuff to emulate the "new static()" stuff in this libraries PHP 5.3 equivalent
        $class = __CLASS__;
        return new $class($data, $from_type);
    }

    /**
     * Do not use this directly, call factory()
     */
    public function __construct($data = null, $from_type = null)
    {
        get_instance()->load->helper('inflector');

        // If the provided data is already formatted we should probably convert it to an array
        if ($from_type !== null)
        {
            if (method_exists($this, '_from_' . $from_type))
            {
                $data = call_user_func(array($this, '_from_' . $from_type), $data);
            }

            else
            {
                throw new Exception('Format class does not support conversion from "' . $from_type . '".');
            }
        }

        $this->_data = $data;
    }

    // FORMATING OUTPUT ---------------------------------------------------------

    public function to_array($data = null)
    {
        // If not just null, but nothing is provided
        if ($data === null and ! func_num_args())
        {
            $data = $this->_data;
        }

        $array = array();

        foreach ((array) $data as $key => $value)
        {
            if (is_object($value) or is_array($value))
            {
                $array[$key] = $this->to_array($value);
            }

            else
            {
                $array[$key] = $value;
            }
        }

        return $array;
    }

    // Format XML for output
    public function to_xml($data = null, $structure = null, $basenode = 'xml')
    {
        if ($data === null and ! func_num_args())
        {
            $data = $this->_data;
        }

        // turn off compatibility mode as simple xml throws a wobbly if you don't.
        if (ini_get('zend.ze1_compatibility_mode') == 1)
        {
            ini_set('zend.ze1_compatibility_mode', 0);
        }

        if ($structure === null)
        {
            $structure = simplexml_load_string("<?xml version='1.0' encoding='utf-8'?><$basenode />");
        }

        // Force it to be something useful
        if ( ! is_array($data) AND ! is_object($data))
        {
            $data = (array) $data;
        }

        foreach ($data as $key => $value)
        {

            //change false/true to 0/1
            if(is_bool($value))
            {
                $value = (int) $value;
            }

            // no numeric keys in our xml please!
            if (is_numeric($key))
            {
                // make string key...
                $key = (singular($basenode) != $basenode) ? singular($basenode) : 'item';
            }

            // replace anything not alpha numeric
            $key = preg_replace('/[^a-z_\-0-9]/i', '', $key);

            // if there is another array found recursively call this function
            if (is_array($value) || is_object($value))
            {
                $node = $structure->addChild($key);

                // recursive call.
                $this->to_xml($value, $node, $key);
            }

            else
            {
                // add single node.
                $value = htmlspecialchars(html_entity_decode($value, ENT_QUOTES, 'UTF-8'), ENT_QUOTES, "UTF-8");

                $structure->addChild($key, $value);
            }
        }

        return $structure->asXML();
    }

    // Format HTML for output
    public function to_html()
    {
        $data = $this->_data;

        // Multi-dimensional array
        if (isset($data[0]) && is_array($data[0]))
        {
            $headings = array_keys($data[0]);
        }

        // Single array
        else
        {
            $headings = array_keys($data);
            $data = array($data);
        }

        $ci = get_instance();
        $ci->load->library('table');

        $ci->table->set_heading($headings);

        foreach ($data as &$row)
        {
            $ci->table->add_row($row);
        }

        return $ci->table->generate();
    }

    // Format CSV for output
    public function to_csv()
    {
        $data = $this->_data;

        // Multi-dimensional array
        if (isset($data[0]) && is_array($data[0]))
        {
            $headings = array_keys($data[0]);
        }

        // Single array
        else
        {
            $headings = array_keys($data);
            $data = array($data);
        }

        $output = implode(',', $headings).PHP_EOL;
        foreach ($data as &$row)
        {
            $output .= '"'.implode('","', $row).'"'.PHP_EOL;
        }

        return $output;
    }

    // Encode as JSON
    public function to_json()
    {
        return json_encode($this->_data);
    }

    // Encode as Serialized array
    public function to_serialized()
    {
        return serialize($this->_data);
    }

    // Output as a string representing the PHP structure
    public function to_php()
    {
        return var_export($this->_data, TRUE);
    }

    // Format XML for output
    protected function _from_xml($string)
    {
        return $string ? (array) simplexml_load_string($string, 'SimpleXMLElement', LIBXML_NOCDATA) : array();
    }

    // Format CSV for output
    // This function is DODGY! Not perfect CSV support but works with my REST_Controller
    protected function _from_csv($string)
    {
        $data = array();

        // Splits
        $rows = explode("\n", trim($string));
        $headings = explode(',', array_shift($rows));
        foreach ($rows as $row)
        {
            // The substr removes " from start and end
            $data_fields = explode('","', trim(substr($row, 1, -1)));

            if (count($data_fields) == count($headings))
            {
                $data[] = array_combine($headings, $data_fields);
            }
        }

        return $data;
    }

    // Encode as JSON
    private function _from_json($string)
    {
        return json_decode(trim($string));
    }

    // Encode as Serialized array
    private function _from_serialize($string)
    {
        return unserialize(trim($string));
    }

}

/* End of file format.php */