<?php

/**
* This class extends Cache_Lite and uses output buffering to get the data to cache.
* It supports nesting of caches
*
* @package Cache_Lite
* @author Markus Tacker <tacker@php.net>
*/

require_once('Cache/Lite/Output.php');

class Cache_Lite_NestedOutput extends Cache_Lite_Output
{
    private $nestedIds = array();
    private $nestedGroups = array();

    /**
    * Start the cache
    *
    * @param string $id cache id
    * @param string $group name of the cache group
    * @param boolean $doNotTestCacheValidity if set to true, the cache validity won't be tested
    * @return boolean|string false if the cache is not hit else the data
    * @access public
    */
    function start($id, $group = 'default', $doNotTestCacheValidity = false)
    {
        $this->nestedIds[] = $id;
        $this->nestedGroups[] = $group;
        $data = $this->get($id, $group, $doNotTestCacheValidity);
        if ($data !== false) {
            return $data;
        }
        ob_start();
        ob_implicit_flush(false);
        return false;
    }

    /**
    * Stop the cache
    *
    * @param boolen
    * @return string return contents of cache
    */
    function end()
    {
        $data = ob_get_contents();
        ob_end_clean();
        $id = array_pop($this->nestedIds);
        $group = array_pop($this->nestedGroups);
        $this->save($data, $id, $group);
        return $data;
    }

}
