summaryrefslogtreecommitdiffstats
path: root/system/libraries/Migration.php
blob: d08afa598d8e96a2d948e3a7091e0962413a8814 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.2.4 or newer
 *
 * NOTICE OF LICENSE
 *
 * Licensed under the Open Software License version 3.0
 *
 * This source file is subject to the Open Software License (OSL 3.0) that is
 * bundled with this package in the files license.txt / license.rst.  It is
 * also available through the world wide web at this URL:
 * http://opensource.org/licenses/OSL-3.0
 * If you did not receive a copy of the license and are unable to obtain it
 * through the world wide web, please send an email to
 * licensing@ellislab.com so we can send you a copy immediately.
 *
 * @package		CodeIgniter
 * @author		EllisLab Dev Team
 * @copyright	Copyright (c) 2006 - 2012, EllisLab, Inc. (http://ellislab.com/)
 * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
 * @link		http://codeigniter.com
 * @since		Version 3.0
 * @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 bool
	 */
	protected $_migration_regex = NULL;

	/**
	 * Error message
	 *
	 * @var string
	 */
	protected $_error_string = '';

	/**
	 * Initialize Migration Class
	 *
	 * @param	array
	 * @return	void
	 */
	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 !== '' 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	int	Target schema version
	 * @return	mixed	TRUE if already latest, FALSE if failed, int if upgraded
	 */
	public function version($target_version)
	{
		$current_version = (int) $this->_get_version();
		$target_version = (int) $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 $file;
			$class = 'Migration_'.ucfirst(strtolower($this->_get_migration_name(basename($file, '.php'))));

			// Validate the migration file structure
			if ( ! class_exists($class))
			{
				$this->_error_string = sprintf($this->lang->line('migration_class_doesnt_exist'), $class);
				return FALSE;
			}
			elseif ( ! is_callable(array($class, $method)))
			{
				$this->_error_string = sprintf($this->lang->line('migration_missing_'.$method.'_method'), $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 > $target_version)
			)
			{
				log_message('debug', 'Migrating '.$method.' from version '.$current_version.' to version '.$number);
				call_user_func(array(new $class, $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;
	}

	// --------------------------------------------------------------------

	/**
	 * Set's the schema to the latest migration
	 *
	 * @return	mixed	true if already latest, false if failed, int if upgraded
	 */
	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 procceed to the standard version migration
		return $this->version($this->_get_migration_number($last_migration));
	}

	// --------------------------------------------------------------------

	/**
	 * 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;
	}

	// --------------------------------------------------------------------

	/**
	 * 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
	 *
	 * @return	int Numeric portion of a migration filename
	 */
	protected function _get_migration_number($migration)
	{
		$parts = explode('_', $migration);
		return (int) $parts[0];
	}

	// --------------------------------------------------------------------

	/**
	 * Extracts the migration class name from a filename
	 *
	 * @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	int	Current Migration
	 */
	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	int	Migration reached
	 * @return	void	Outputs a report of the migration
	 */
	protected function _update_version($migration)
	{
		return $this->db->update($this->_migration_table, array(
			'version' => $migration
		));
	}

	// --------------------------------------------------------------------

	/**
	 * Enable the use of CI super-global
	 *
	 * @param	$var
	 * @return	mixed
	 */
	public function __get($var)
	{
		return get_instance()->$var;
	}

}

/* End of file Migration.php */
/* Location: ./system/libraries/Migration.php */