summaryrefslogtreecommitdiffstats
path: root/system/libraries/Migration.php
blob: 682d907526fdc3a25bd71256401f7ec98c62fbaf (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
<?php defined('BASEPATH') OR 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 - 2011, EllisLab, Inc.
 * @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 $_migration_table = 'migrations';
	
	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();

		// Make sure the migration table name was set.
		if ( (! isset($this->_migration_table)) OR (empty($this->_migration_table)))
		{
			show_error('Migrations configuration file (migration.php) must have "migration_table" set.');			
		}

		// If the migrations table is missing, make it
		if ( ! $this->db->table_exists($this->_migration_table))
		{
			$this->dbforge->add_field(array(
				'version' => array('type' => 'INT', 'constraint' => 3),
			));

			$this->dbforge->create_table($this->_migration_table, TRUE);

			$this->db->insert($this->_migration_table, array('version' => 0));
		}
	}

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

	/**
	 * Migrate to a schema version
	 *
	 * Calls each migration step required to get to the schema version of
	 * choice
	 *
	 * @access	public
	 * @param $version integer	Target schema version
	 * @return	mixed	TRUE if already latest, FALSE if failed, int if upgraded
	 */
	public function version($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
	 *
	 * @access	public
	 * @return	mixed	true if already latest, false if failed, int if upgraded
	 */
	public function latest()
	{
		if ( ! $migrations = $this->find_migrations())
		{
			$this->_error_string = $this->line->lang('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
	 *
	 * @access	public
	 * @return	mixed	true if already current, false if failed, int if upgraded
	 */
	public function current()
	{
		return $this->version($this->_migration_version);
	}

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

	/**
	 * Error string
	 *
	 * @access	public
	 * @return	string	Error message returned as a string
	 */
	public function error_string()
	{
		return $this->_error_string;
	}

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

	/**
	 * Set's the schema to the latest migration
	 *
	 * @access	protected
	 * @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
	 *
	 * @access	protected
	 * @return	integer	Current Migration
	 */
	protected function _get_version()
	{
		$row = $this->db->get($this->_migration_table)->row();
		return $row ? $row->version : 0;
	}

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

	/**
	 * Stores the current schema version
	 *
	 * @access	protected
	 * @param $migrations integer	Migration reached
	 * @return	void					Outputs a report of the migration
	 */
	protected function _update_version($migrations)
	{
		return $this->db->update($this->_migration_table, array(
			'version' => $migrations
		));
	}

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

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

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