Migration command for Yii that allows for adding (and removing) of external migrations.

MigratePathCommand.php

<?php

Yii::import('system.cli.commands.MigrateCommand');

class MigratePathCommand extends MigrateCommand
{
    /**
     * @var string
     */
    public $migrationTable = 'migration';
    /**
     * @var string
     */
    public $migrationFile = 'migrations';

    /**
     * Adds a migration path from the registry.
     * @param $args
     * @throws CException
     */
    public function actionAddPath($args)
    {
        echo "Adding migration path ... ";
        if (!isset($args[0])) {
            $this->usageError("Please provide a migration path to add.");
        }
        $path = $args[0];
        $migrations = $this->readMigrationsFile();
        $relativePath = $this->migrationPath . DIRECTORY_SEPARATOR . $path;
        if (is_dir($relativePath)) {
            $migrations = $this->normalizeMigrations($migrations);
            if (!in_array($path, $migrations)) {
                $migrations[] = $path;
                $this->writeMigrationFile($migrations);
                echo "done\n";
            } else {
                echo "skipped (already registered)\n";
            }
        } else {
            echo "skipped (path not found)\n";
        }
    }

    /**
     * Removes a migration path from the registry.
     * @param $args
     */
    public function actionRemovePath($args)
    {
        echo "Removing migration path ... ";
        if (!isset($args[0])) {
            $this->usageError("Please provide a migration path to remove.");
        }
        $path = $args[0];
        $migrations = $this->readMigrationsFile();
        $migrations = $this->normalizeMigrations($migrations);
        if (($index = array_search($path, $migrations)) !== false) {
            unset($migrations[$index]);
            $this->writeMigrationFile($migrations);
            echo "done\n";
        } else {
            echo "skipped (not found)\n";
        }
    }

    /**
     * @return string
     */
    public function getHelp()
    {
        return parent::getHelp() . <<<EOD

 * yiic migrate addPath ../../path/to/migrations
   Adds a migration path (relative to the application migrations path).

 * yiic migrate removePath ../../path/to/migrations
   Remove a migration path (relative to the application migrations path).

EOD;
    }


    /**
     * @param $class
     */
    protected function instantiateMigration($class)
    {
        foreach ($this->getMigrationPaths() as $path) {
            $file = $path . DIRECTORY_SEPARATOR . $class . '.php';
            if (file_exists($file) && is_file($file)) {
                require_once($file);
                /* @var CDbMigration $migration */
                $migration = new $class;
                $migration->setDbConnection($this->getDbConnection());
                return $migration;
            }
        }
        return null;
    }

    /**
     * @return array
     */
    protected function getNewMigrations()
    {
        $applied = array();
        foreach ($this->getMigrationHistory(-1) as $version => $time) {
            $applied[substr($version, 1, 13)] = true;
        }

        $migrations = array();
        foreach ($this->getMigrationPaths() as $migrationPath) {
            $handle = opendir($migrationPath);
            while (($file = readdir($handle)) !== false) {
                if ($file === '.' || $file === '..') {
                    continue;
                }
                $path = $migrationPath . DIRECTORY_SEPARATOR . $file;
                if (preg_match('/^(m(\d{6}_\d{6})_.*?)\.php$/', $file, $matches) && is_file(
                        $path
                    ) && !isset($applied[$matches[2]])
                ) {
                    $migrations[] = $matches[1];
                }
            }
            closedir($handle);
        }
        sort($migrations);
        return $migrations;
    }

    /**
     * @return array
     */
    protected function getMigrationPaths()
    {
        return array_merge(array($this->migrationPath), $this->readMigrationsFile());
    }

    /**
     * @return mixed
     */
    protected function readMigrationsFile()
    {
        $migrationFile = $this->resolveMigrationFilePath();
        if (!file_exists($migrationFile)) {
            $this->writeMigrationFile();
        }
        return require($migrationFile);
    }

    /**
     * @param array $migrations
     */
    protected function writeMigrationFile($migrations = array())
    {
        ob_start();
        echo "<?php\n\n";
        echo "// {$this->migrationFile}.php generated by MigrationCommand\n\n";
        echo "\$migrationDir = __DIR__;\n\n";
        echo "return array(\n";
        foreach ($migrations as $value) {
            echo "\t\$migrationDir . '/" . $value . "',\n";
        }
        echo ');\n';
        $migrationFile = $this->resolveMigrationFilePath();
        file_put_contents($migrationFile, ob_get_clean());
    }

    /**
     * @param $migrations
     * @return mixed
     */
    protected function normalizeMigrations($migrations)
    {
        foreach ($migrations as &$path) {
            $path = ltrim(str_replace($this->migrationPath, '', $path), '/');
        }
        return $migrations;
    }

    /**
     * @return string
     */
    protected function resolveMigrationFilePath()
    {
        return $this->migrationPath . '/' . $this->migrationFile . '.php';
    }
}