From 9758d84b69185f80fd8197f28046af7ef3b2a2d3 Mon Sep 17 00:00:00 2001 From: Phil Sturgeon Date: Mon, 7 Feb 2011 20:39:00 +0000 Subject: Added Migrations library, config and an example controller/migration file. --- system/libraries/Migration.php | 336 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 336 insertions(+) create mode 100644 system/libraries/Migration.php (limited to 'system/libraries') diff --git a/system/libraries/Migration.php b/system/libraries/Migration.php new file mode 100644 index 000000000..73c55c346 --- /dev/null +++ b/system/libraries/Migration.php @@ -0,0 +1,336 @@ + $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, '/').'/'; + + // 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 + * + * @access public + * @param $version integer Target schema version + * @return mixed TRUE if already latest, FALSE if failed, int if upgraded + */ + function version($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) + { + $this->error = sprintf($this->lang->line('multiple_migration_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. + $this->error = sprintf($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)) + { + $this->error = sprintf($this->lang->line('multiple_migrations_name'), $match[1]); + return FALSE; + } + + include $f[0]; + $class = 'Migration_' . ucfirst($match[1]); + + if ( ! class_exists($class)) + { + $this->error = sprintf($this->lang->line('migration_class_doesnt_exist'), $class); + return FALSE; + } + + if ( ! is_callable(array($class, 'up')) || ! is_callable(array($class, 'down'))) + { + $this->error = sprintf($this->lang->line('wrong_migration_interface'), $class); + return FALSE; + } + + $migrations[] = $match[1]; + } + else + { + $this->error = sprintf($this->lang->line('invalid_migration_filename'), $file); + return FALSE; + } + } + + $this->log('Current schema version: ' . $current_version); + + $version = $i + ($step == 1 ? -1 : 0); + + // If there is nothing to do so quit + if ($migrations === array()) + { + return TRUE; + } + + $this->log('Moving ' . $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); + } + + $this->log('All done. Schema is at version '.$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()) + { + throw new Exception('no_migrations_found'); + return false; + } + + $last_migration = basename(end($migrations)); + + // Calculate the last migration step from existing migration + // filenames and procceed to the standard version migration + $last_version = intval(substr($last_migration, 0, 3)); + return $this->version($last_version); + } + + // -------------------------------------------------------------------- + + /** + * 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() + { + $version = $this->_migration_version; + return $this->version($version); + } + + // -------------------------------------------------------------------- + + /** + * Set's the schema to the latest migration + * + * @access public + * @return mixed true if already latest, false if failed, int if upgraded + */ + + protected static 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 private + * @return integer Current Schema version + */ + private function _get_version() + { + $row = $this->db->get('migrations')->row(); + return $row ? $row->version : 0; + } + + // -------------------------------------------------------------------- + + /** + * Stores the current schema version + * + * @access private + * @param $migrations integer Schema version reached + * @return void Outputs a report of the migration + */ + private function _update_version($migrations) + { + return $this->db->update('migrations', array( + 'version' => $migrations + )); + } + + // -------------------------------------------------------------------- + + /** + * Stores the current schema version + * + * @access private + * @param $migrations integer Schema version reached + * @return void Outputs a report of the migration + */ + private function log($text) + { + echo $text.'
'; + } + + // -------------------------------------------------------------------- + + /** + * Enable the use of CI super-global + * + * @access public + * @param $var + * @return mixed + */ + public function __get($var) + { + return get_instance()->$var; + } +} \ No newline at end of file -- cgit v1.2.3-24-g4f1b