<?php
/**
* Kunena Component
* @package Kunena.Framework
*
* @copyright (C) 2008 - 2014 Kunena Team. All rights reserved.
* @license http://www.gnu.org/copyleft/gpl.html GNU/GPL
* @link http://www.kunena.org
**/
defined ( '_JEXEC' ) or die ();
/**
* Class KunenaInstaller
*/
class KunenaInstaller {
// Minimum supported versions during downgrade.
protected static $downgrade = array('3.0' => '3.0.0-DEV', '2.9' => '2.9.90-DEV', '2.0' => '2.0.4');
protected static $tables = null;
/**
* Check if we are allowed to downgrade from the new to the old version.
*
* @param string $version
* @return boolean True if version can be safely downgraded.
*/
public static function canDowngrade($version) {
if ($version == '@'.'kunenaversion'.'@') return true;
foreach (self::$downgrade as $major=>$minor) {
if (version_compare ( $version, $major, "<" )) continue;
if (version_compare ( $version, $minor, ">=" )) return true;
}
return false;
}
/**
* Get Kunena database schema version.
*
* @return string Version number or null.
*/
public static function getSchemaVersion() {
// Check if Kunena can be found from the database.
if (!self::detectTable('kunena_version')) return null;
// Get installed version.
$db = JFactory::getDBO();
$db->setQuery("SELECT version FROM {$db->quoteName('#__kunena_version')} WHERE state='' ORDER BY id DESC", 0, 1);
$version = $db->loadResult();
return $version;
}
/**
* Detect if table exists in the database.
*
* @param string $table Table name to be found.
* @param string $prefix Database prefix.
* @param bool $reload Reload all tables.
*
* @return boolean True if the table exists in the database.
*/
public static function detectTable($table, $prefix = '#__', $reload = false) {
$db = JFactory::getDBO();
if (self::$tables === null || $reload) {
$list = $db->getTableList();
self::$tables = array();
foreach ($list as $item) {
self::$tables[$item] = false;
}
}
if ($prefix == '#__') $prefix = $db->getPrefix();
$table = $prefix . $table;
return isset(self::$tables[$table]);
}
/**
* Get column type in the table.
*
* @param string $table Table name to be found.
* @param string $column Table column to be searched.
* @param string $prefix Database prefix.
* @param boolean $reload Reload all tables.
*
* @return string|null Column type or NULL if either table or column does not exist.
*/
public static function getTableColumn($table, $column, $prefix = '#__', $reload = false) {
if (!self::detectTable($table, $prefix, $reload)) return false;
$db = JFactory::getDBO();
if ($prefix == '#__') $prefix = $db->getPrefix();
$table = $prefix . $table;
if (!isset(self::$tables[$table]['columns'])) {
self::$tables[$table]['columns'] = $db->getTableColumns($table);
}
return isset(self::$tables[$table]['columns'][$column]) ? self::$tables[$table]['columns'][$column] : null;
}
}