system/libraries/Migration.php
<?php
/**
* CodeIgniter
*
* An open source application development framework for PHP
*
* This content is released under the MIT License (MIT)
*
* Copyright (c) 2019 - 2022, CodeIgniter Foundation
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* @package CodeIgniter
* @author EllisLab Dev Team
* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
* @copyright Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
* @copyright Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/)
* @license https://opensource.org/licenses/MIT MIT License
* @link https://codeigniter.com
* @since Version 3.0.0
* @filesource
*/
defined('BASEPATH') OR exit('No direct script access allowed');
/**
* 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 {
/**
* Whether the library is enabled
*
* @var bool
*/
protected $_migration_enabled = FALSE;
/**
* Migration numbering type
*
* @var bool
*/
protected $_migration_type = 'sequential';
/**
* Path to migration classes
*
* @var string
*/
protected $_migration_path = NULL;
/**
* Current migration version
*
* @var mixed
*/
protected $_migration_version = 0;
/**
* Database table with migration info
*
* @var string
*/
protected $_migration_table = 'migrations';
/**
* Whether to automatically run migrations
*
* @var bool
*/
protected $_migration_auto_latest = FALSE;
/**
* Migration basename regex
*
* @var string
*/
protected $_migration_regex;
/**
* Error message
*
* @var string
*/
protected $_error_string = '';
/**
* Initialize Migration Class
*
* @param array $config
* @return void
*/
public function __construct($config = array())
{
// Only run this constructor on main library load
if ( ! in_array(get_class($this), array('CI_Migration', config_item('subclass_prefix').'Migration'), TRUE))
{
return;
}
foreach ($config as $key => $val)
{
$this->{'_'.$key} = $val;
}
log_message('info', 'Migrations Class Initialized');
// Are they trying to use migrations while it is disabled?
if ($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 !== '' OR $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
$this->load->dbforge();
// Make sure the migration table name was set.
if (empty($this->_migration_table))
{
show_error('Migrations configuration file (migration.php) must have "migration_table" set.');
}
// Migration basename regex
$this->_migration_regex = ($this->_migration_type === 'timestamp')
? '/^\d{14}_(\w+)$/'
: '/^\d{3}_(\w+)$/';
// Make sure a valid migration numbering type was set.
if ( ! in_array($this->_migration_type, array('sequential', 'timestamp')))
{
show_error('An invalid migration numbering type was specified: '.$this->_migration_type);
}
// If the migrations table is missing, make it
if ( ! $this->db->table_exists($this->_migration_table))
{
$this->dbforge->add_field(array(
'version' => array('type' => 'BIGINT', 'constraint' => 20),
));
$this->dbforge->create_table($this->_migration_table, TRUE);
$this->db->insert($this->_migration_table, array('version' => 0));
}
// Do we auto migrate to the latest migration?
if ($this->_migration_auto_latest === TRUE && ! $this->latest())
{
show_error($this->error_string());
}
}
// --------------------------------------------------------------------
/**
* Migrate to a schema version
*
* Calls each migration step required to get to the schema version of
* choice
*
* @param string $target_version Target schema version
* @return mixed TRUE if no migrations are found, current version string on success, FALSE on failure
*/
public function version($target_version)
{
// Note: We use strings, so that timestamp versions work on 32-bit systems
$current_version = $this->_get_version();
if ($this->_migration_type === 'sequential')
{
$target_version = sprintf('%03d', $target_version);
}
else
{
$target_version = (string) $target_version;
}
$migrations = $this->find_migrations();
if ($target_version > 0 && ! isset($migrations[$target_version]))
{
$this->_error_string = sprintf($this->lang->line('migration_not_found'), $target_version);
return FALSE;
}
if ($target_version > $current_version)
{
$method = 'up';
}
elseif ($target_version < $current_version)
{
$method = 'down';
// We need this so that migrations are applied in reverse order
krsort($migrations);
}
else
{
// Well, there's nothing to migrate then ...
return TRUE;
}
// Validate all available migrations within our target range.
//
// Unfortunately, we'll have to use another loop to run them
// in order to avoid leaving the procedure in a broken state.
//
// See https://github.com/bcit-ci/CodeIgniter/issues/4539
$pending = array();
foreach ($migrations as $number => $file)
{
// Ignore versions out of our range.
//
// Because we've previously sorted the $migrations array depending on the direction,
// we can safely break the loop once we reach $target_version ...
if ($method === 'up')
{
if ($number <= $current_version)
{
continue;
}
elseif ($number > $target_version)
{
break;
}
}
else
{
if ($number > $current_version)
{
continue;
}
elseif ($number <= $target_version)
{
break;
}
}
// Check for sequence gaps
if ($this->_migration_type === 'sequential')
{
if (isset($previous) && abs($number - $previous) > 1)
{
$this->_error_string = sprintf($this->lang->line('migration_sequence_gap'), $number);
return FALSE;
}
$previous = $number;
}
include_once($file);
$class = 'Migration_'.ucfirst(strtolower($this->_get_migration_name(basename($file, '.php'))));
// Validate the migration file structure
if ( ! class_exists($class, FALSE))
{
$this->_error_string = sprintf($this->lang->line('migration_class_doesnt_exist'), $class);
return FALSE;
}
elseif ( ! method_exists($class, $method) OR ! (new ReflectionMethod($class, $method))->isPublic())
{
$this->_error_string = sprintf($this->lang->line('migration_missing_'.$method.'_method'), $class);
return FALSE;
}
$pending[$number] = array($class, $method);
}
// Now just run the necessary migrations
foreach ($pending as $number => $migration)
{
log_message('debug', 'Migrating '.$method.' from version '.$current_version.' to version '.$number);
$migration[0] = new $migration[0];
call_user_func($migration);
$current_version = $number;
$this->_update_version($current_version);
}
// This is necessary when moving down, since the the last migration applied
// will be the down() method for the next migration up from the target
if ($current_version <> $target_version)
{
$current_version = $target_version;
$this->_update_version($current_version);
}
log_message('debug', 'Finished migrating to '.$current_version);
return $current_version;
}
// --------------------------------------------------------------------
/**
* Sets the schema to the latest migration
*
* @return mixed Current version string on success, FALSE on failure
*/
public function latest()
{
$migrations = $this->find_migrations();
if (empty($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 proceed to the standard version migration
return $this->version($this->_get_migration_number($last_migration));
}
// --------------------------------------------------------------------
/**
* Sets the schema to the migration version set in config
*
* @return mixed TRUE if no migrations are found, current version string on success, FALSE on failure
*/
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;
}
// --------------------------------------------------------------------
/**
* Retrieves list of available migration scripts
*
* @return array list of migration file paths sorted by version
*/
public function find_migrations()
{
$migrations = array();
// Load all *_*.php files in the migrations path
foreach (glob($this->_migration_path.'*_*.php') as $file)
{
$name = basename($file, '.php');
// Filter out non-migration files
if (preg_match($this->_migration_regex, $name))
{
$number = $this->_get_migration_number($name);
// There cannot be duplicate migration numbers
if (isset($migrations[$number]))
{
$this->_error_string = sprintf($this->lang->line('migration_multiple_version'), $number);
show_error($this->_error_string);
}
$migrations[$number] = $file;
}
}
ksort($migrations);
return $migrations;
}
// --------------------------------------------------------------------
/**
* Extracts the migration number from a filename
*
* @param string $migration
* @return string Numeric portion of a migration filename
*/
protected function _get_migration_number($migration)
{
return sscanf($migration, '%[0-9]+', $number)
? $number : '0';
}
// --------------------------------------------------------------------
/**
* Extracts the migration class name from a filename
*
* @param string $migration
* @return string text portion of a migration filename
*/
protected function _get_migration_name($migration)
{
$parts = explode('_', $migration);
array_shift($parts);
return implode('_', $parts);
}
// --------------------------------------------------------------------
/**
* Retrieves current schema version
*
* @return string Current migration version
*/
protected function _get_version()
{
$row = $this->db->select('version')->get($this->_migration_table)->row();
return $row ? $row->version : '0';
}
// --------------------------------------------------------------------
/**
* Stores the current schema version
*
* @param string $migration Migration reached
* @return void
*/
protected function _update_version($migration)
{
$this->db->update($this->_migration_table, array(
'version' => $migration
));
}
// --------------------------------------------------------------------
/**
* Enable the use of CI super-global
*
* @param string $var
* @return mixed
*/
public function __get($var)
{
return get_instance()->$var;
}
}