www.gusucode.com > PHP开源客户管理系统 v1.0PHP源码程序 > PHP开源客户管理系统 v1.0/khglxt_A5/khglxt_A5/system/libraries/Migration.php
<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
/**
* CodeIgniter
*
* An open source application development framework for PHP 5.1.6 or newer
*
* @package CodeIgniter
* @author EllisLab Dev Team
* @copyright Copyright (c) 2006 - 2014, EllisLab, Inc.
* @copyright Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
* @license http://codeigniter.com/user_guide/license.html
* @link http://codeigniter.com
* @since Version 1.0
* @filesource
*/
// ------------------------------------------------------------------------
/**
* Migration Class
*
* All migrations should implement this, forces up() and down() and gives
* access to the CI super-global.
*
* @package CodeIgniter
* @subpackage Libraries
* @category Libraries
* @author Reactor Engineers
* @link
*/
class CI_Migration {
protected $_migration_enabled = FALSE;
protected $_migration_path = NULL;
protected $_migration_version = 0;
protected $_error_string = '';
public function __construct($config = array())
{
# Only run this constructor on main library load
if (get_parent_class($this) !== FALSE)
{
return;
}
foreach ($config as $key => $val)
{
$this->{'_' . $key} = $val;
}
log_message('debug', 'Migrations class initialized');
// Are they trying to use migrations while it is disabled?
if ($this->_migration_enabled !== TRUE)
{
show_error('Migrations has been loaded but is disabled or set up incorrectly.');
}
// If not set, set it
$this->_migration_path == '' AND $this->_migration_path = APPPATH . 'migrations/';
// Add trailing slash if not set
$this->_migration_path = rtrim($this->_migration_path, '/').'/';
// Load migration language
$this->lang->load('migration');
// They'll probably be using dbforge
$this->load->dbforge();
// If the migrations table is missing, make it
if ( ! $this->db->table_exists('migrations'))
{
$this->dbforge->add_field(array(
'version' => array('type' => 'INT', 'constraint' => 3),
));
$this->dbforge->create_table('migrations', TRUE);
$this->db->insert('migrations', array('version' => 0));
}
}
// --------------------------------------------------------------------
/**
* Migrate to a schema version
*
* Calls each migration step required to get to the schema version of
* choice
*
* @param int Target schema version
* @return mixed TRUE if already latest, FALSE if failed, int if upgraded
*/
public function version($target_version)
{
$start = $current_version = $this->_get_version();
$stop = $target_version;
if ($target_version > $current_version)
{
// Moving Up
++$start;
++$stop;
$step = 1;
}
else
{
// Moving Down
$step = -1;
}
$method = ($step === 1) ? 'up' : 'down';
$migrations = array();
// We now prepare to actually DO the migrations
// But first let's make sure that everything is the way it should be
for ($i = $start; $i != $stop; $i += $step)
{
$f = glob(sprintf($this->_migration_path . '%03d_*.php', $i));
// Only one migration per step is permitted
if (count($f) > 1)
{
$this->_error_string = sprintf($this->lang->line('migration_multiple_version'), $i);
return FALSE;
}
// Migration step not found
if (count($f) == 0)
{
// If trying to migrate up to a version greater than the last
// existing one, migrate to the last one.
if ($step == 1)
{
break;
}
// If trying to migrate down but we're missing a step,
// something must definitely be wrong.
$this->_error_string = sprintf($this->lang->line('migration_not_found'), $i);
return FALSE;
}
$file = basename($f[0]);
$name = basename($f[0], '.php');
// Filename validations
if (preg_match('/^\d{3}_(\w+)$/', $name, $match))
{
$match[1] = strtolower($match[1]);
// Cannot repeat a migration at different steps
if (in_array($match[1], $migrations))
{
$this->_error_string = sprintf($this->lang->line('migration_multiple_version'), $match[1]);
return FALSE;
}
include $f[0];
$class = 'Migration_' . ucfirst($match[1]);
if ( ! class_exists($class))
{
$this->_error_string = sprintf($this->lang->line('migration_class_doesnt_exist'), $class);
return FALSE;
}
if ( ! is_callable(array($class, $method)))
{
$this->_error_string = sprintf($this->lang->line('migration_missing_'.$method.'_method'), $class);
return FALSE;
}
$migrations[] = $match[1];
}
else
{
$this->_error_string = sprintf($this->lang->line('migration_invalid_filename'), $file);
return FALSE;
}
}
log_message('debug', 'Current migration: ' . $current_version);
$version = $i + ($step == 1 ? -1 : 0);
// If there is nothing to do so quit
if ($migrations === array())
{
return TRUE;
}
log_message('debug', 'Migrating from ' . $method . ' to version ' . $version);
// Loop through the migrations
foreach ($migrations AS $migration)
{
// Run the migration class
$class = 'Migration_' . ucfirst(strtolower($migration));
call_user_func(array(new $class, $method));
$current_version += $step;
$this->_update_version($current_version);
}
log_message('debug', 'Finished migrating to '.$current_version);
return $current_version;
}
// --------------------------------------------------------------------
/**
* Set's the schema to the latest migration
*
* @return mixed true if already latest, false if failed, int if upgraded
*/
public function latest()
{
if ( ! $migrations = $this->find_migrations())
{
$this->_error_string = $this->lang->line('migration_none_found');
return false;
}
$last_migration = basename(end($migrations));
// Calculate the last migration step from existing migration
// filenames and procceed to the standard version migration
return $this->version((int) substr($last_migration, 0, 3));
}
// --------------------------------------------------------------------
/**
* Set's the schema to the migration version set in config
*
* @return mixed true if already current, false if failed, int if upgraded
*/
public function current()
{
return $this->version($this->_migration_version);
}
// --------------------------------------------------------------------
/**
* Error string
*
* @return string Error message returned as a string
*/
public function error_string()
{
return $this->_error_string;
}
// --------------------------------------------------------------------
/**
* Set's the schema to the latest migration
*
* @return mixed true if already latest, false if failed, int if upgraded
*/
protected function find_migrations()
{
// Load all *_*.php files in the migrations path
$files = glob($this->_migration_path . '*_*.php');
$file_count = count($files);
for ($i = 0; $i < $file_count; $i++)
{
// Mark wrongly formatted files as false for later filtering
$name = basename($files[$i], '.php');
if ( ! preg_match('/^\d{3}_(\w+)$/', $name))
{
$files[$i] = FALSE;
}
}
sort($files);
return $files;
}
// --------------------------------------------------------------------
/**
* Retrieves current schema version
*
* @return int Current Migration
*/
protected function _get_version()
{
$row = $this->db->get('migrations')->row();
return $row ? $row->version : 0;
}
// --------------------------------------------------------------------
/**
* Stores the current schema version
*
* @param int Migration reached
* @return bool
*/
protected function _update_version($migrations)
{
return $this->db->update('migrations', array(
'version' => $migrations
));
}
// --------------------------------------------------------------------
/**
* Enable the use of CI super-global
*
* @param mixed $var
* @return mixed
*/
public function __get($var)
{
return get_instance()->$var;
}
}
/* End of file Migration.php */
/* Location: ./system/libraries/Migration.php */