<?php

/**

 * MySQL Resource

 * Resource Implementation based on the Custom API to use

 * MySQL as the storage resource for Smarty's templates and configs.

 * Table definition:

 * <pre>CREATE TABLE IF NOT EXISTS `templates` (

 *   `name` varchar(100) NOT NULL,

 *   `modified` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,

 *   `source` text,

 *   PRIMARY KEY (`name`)

 * ) ENGINE=InnoDB DEFAULT CHARSET=utf8;</pre>

 * Demo data:

 * <pre>INSERT INTO `templates` (`name`, `modified`, `source`) VALUES ('test.tpl', "2010-12-25 22:00:00", '{$x="hello world"}{$x}');</pre>

 *

 * @package Resource-examples

 * @author  Rodney Rehm

 */

class Smarty_Resource_Mysql extends Smarty_Resource_Custom {

    // PDO instance

    protected $db;

    // prepared fetch() statement

    protected $fetch;

    // prepared fetchTimestamp() statement

    protected $mtime;

    public function __construct() {

        try {

            $this->db = new PDO("mysql:dbname=test;host=127.0.0.1", "smarty");

        } catch (PDOException $e) {

            throw new SmartyException('Mysql Resource failed: ' . $e->getMessage());

        }

        $this->fetch = $this->db->prepare('SELECT modified, source FROM templates WHERE name = :name');

        $this->mtime = $this->db->prepare('SELECT modified FROM templates WHERE name = :name');

    }

    /**

     * Fetch a template and its modification time from database

     *

     * @param  string $name template name

     * @param  string $source template source

     * @param  integer $mtime template modification timestamp (epoch)

     *

     * @return void

     */

    protected function fetch($name, &$source, &$mtime) {

        $this->fetch->execute(array('name' => $name));

        $row = $this->fetch->fetch();

        $this->fetch->closeCursor();

        if ($row) {

            $source = $row['source'];

            $mtime = strtotime($row['modified']);

        } else {

            $source = null;

            $mtime = null;

        }

    }

    /**

     * Fetch a template's modification time from database

     *

     * @note implementing this method is optional. Only implement it if modification times can be accessed faster than loading the comple template source.

     *

     * @param  string $name template name

     *

     * @return integer timestamp (epoch) the template was modified

     */

    protected function fetchTimestamp($name) {

        $this->mtime->execute(array('name' => $name));

        $mtime = $this->mtime->fetchColumn();

        $this->mtime->closeCursor();

        return strtotime($mtime);

    }

}