Migrate::version PHP Method

    public function version($version = 0)
    {
        $output = '';
        if ($version == 0) {
            $files = glob($this->migrations_path . "*" . EXT);
            $version = count($files);
        }
        $schema_version = $this->_get_db_schema_version();
        $start = $schema_version;
        $stop = $version;
        if ($version > $schema_version) {
            // Moving Up to the east side
            $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->migrations_path . '%03d_*.php', $i));
            // Only one migration per step is permitted
            if (count($f) > 1) {
                $this->error = sprintf($this->_ci->lang->line("multiple_migrations_version"), $i);
                return 0;
            }
            // Migration step not found
            if (count($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->_ci->lang->line("migration_not_found"), $i);
                return 0;
            }
            $file = basename($f[0]);
            $name = basename($f[0], EXT);
            // 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->_ci->lang->line("multiple_migrations_name"), $match[1]);
                    return 0;
                }
                include $f[0];
                $class = ucfirst($match[1]);
                if (!class_exists($class)) {
                    $this->error = sprintf($this->_ci->lang->line("migration_class_doesnt_exist"), $class);
                    return 0;
                }
                if (!is_callable(array($class, "up")) or !is_callable(array($class, "down"))) {
                    $this->error = sprintf($this->_ci->lang->line('wrong_migration_interface'), $class);
                    return 0;
                }
                $migrations[] = $match[1];
            } else {
                $this->error = sprintf($this->_ci->lang->line("invalid_migration_filename"), $file);
                return 0;
            }
        }
        $version = $i + ($step == 1 ? -1 : 0);
        // If there is any migration to proccess
        if (count($migrations)) {
            if ($this->verbose) {
                $output .= "<p>Current db schema version: " . $schema_version . "<br/>";
                $output .= "Moving " . $method . " to version " . $version . "</p>";
                $output .= "<hr/>";
            }
            // Loop Through the migrations
            foreach ($migrations as $m) {
                if ($this->verbose) {
                    $output .= "{$m}:<br />";
                    $output .= "<blockquote>";
                }
                $class = ucfirst($m);
                // As of 5.2.3
                $myobject = new $class();
                $output .= call_user_func(array($myobject, $method));
                if ($this->verbose) {
                    $output .= "</blockquote>";
                    $output .= "<hr/>";
                }
                $schema_version += $step;
                $this->_update_schema_version($schema_version);
            }
            if ($this->verbose) {
                $output .= sprintf(lang('all_done'), $schema_version);
            }
        } else {
            if ($this->verbose) {
                $output .= lang('nothing_to_do');
            }
        }
        return $output;
    }

 public static function down()
 {
     \Config::load('migrate', true);
     $version = \Config::get('migrate.version') - 1;
     if (\Migrate::version($version)) {
         static::_update_version($version);
     }
 }