ci-bonfire / Sprint

system/libraries/Migration.php

<?php

For compatibility and reusability of your code, PSR1 recommends that a file should introduce either new symbols (like classes, functions, etc.) or have side-effects (like outputting something, or including other files), but not both at the same time. The first symbol is defined on line 52 and the first side effect is on line 38.

/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2015, British Columbia Institute of Technology
 *
 * 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. (http://ellislab.com/)
 * @copyright	Copyright (c) 2014 - 2015, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	http://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 {

The type CI_Migration has been defined more than once; this definition is ignored, only the first definition in application/libraries/Migration.php (L52-578) is considered.

	/**
	 * 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 bool
	 */
	protected $_migration_regex = NULL;

	/**
	 * 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)
		{
			// Moving Up
			$method = 'up';
		}
		else
		{
			// Moving Down, apply in reverse order
			$method = 'down';
			krsort($migrations);
		}

		if (empty($migrations))
		{
			return TRUE;
		}

		$previous = FALSE;

		// Validate all available migrations, and run the ones within our target range
		foreach ($migrations as $number => $file)
		{
			// Check for sequence gaps
			if ($this->_migration_type === 'sequential' && $previous !== FALSE && abs($number - $previous) > 1)
			{
				$this->_error_string = sprintf($this->lang->line('migration_sequence_gap'), $number);
				return FALSE;
			}

			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;
			}

			$previous = $number;

			// Run migrations that are inside the target range
			if (
				($method === 'up'   && $number > $current_version && $number <= $target_version) OR
				($method === 'down' && $number <= $current_version && $number > $target_version)
			)
			{
				$instance = new $class();
				if ( ! is_callable(array($instance, $method)))
				{
					$this->_error_string = sprintf($this->lang->line('migration_missing_'.$method.'_method'), $class);
					return FALSE;
				}

				log_message('debug', 'Migrating '.$method.' from version '.$current_version.' to version '.$number);
				call_user_func(array($instance, $method));
				$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;
	}

}