Changing migration system so that the migration manager is responsible for organising dry-runs

This makes more sense from a structural point of view, and reduces the complexity of the db:migrate code.
Can now successfully do a dry run with query output :)

Also added a view so as to display task results.

classes/minion/migration/manager.php

@@ -21,6 +21,24 @@ class Minion_Migration_Manager {
 	 */
 	protected $_model;
 
+	/**
+	 * Whether this is a dry run migration
+	 * @var boolean
+	 */
+	protected $_dry_run = FALSE;
+
+	/**
+	 * A set of SQL queries that were generated on the dry run
+	 * @var array
+	 */
+	protected $_dry_run_sql = array();
+
+	/**
+	 * Set of migrations that were executed
+	 */
+	protected $_executed_migrations = array();
+
+
 	/**
 	 * Constructs the object, allows injection of a Database connection
 	 *
@@ -64,6 +82,30 @@ class Minion_Migration_Manager {
 		return $this;
 	}
 
+	/**
+	 * Set whether the manager should execute a dry run instead of a real run
+	 *
+	 * @param boolean Whether we should do a dry run
+	 * @return Minion_Migration_Manager
+	 */
+	public function set_dry_run($dry_run)
+	{
+		$this->_dry_run = (bool) $dry_run;
+
+		return $this;
+	}
+
+	/**
+	 * Ruturns a set of queries that would've been executed had dry run not been 
+	 * enabled.  If dry run was not enabled, this returns an empty array
+	 *
+	 * @return array SQL Queries
+	 */
+	public function get_dry_run_sql()
+	{
+		return $this->_dry_run_sql;
+	}
+
 	/**
 	 * Run migrations in the specified locations so as to reach specified targets
 	 *
@@ -97,14 +139,14 @@ class Minion_Migration_Manager {
 	 * @param  array   Set of locations to update, empty array means all
 	 * @param  array   Versions for specified locations
 	 * @param  boolean The default direction (up/down) for migrations without a specific version
-	 * @param  boolean Whether successful migrations should be recorded
 	 * @return array   Array of all migrations that were successfully applied
 	 */
-	public function run_migration(array $locations = array(), $versions = array(), $default_direction = TRUE, $record_success = TRUE)
+	public function run_migration(array $locations = array(), $versions = array(), $default_direction = TRUE)
 	{
 		$migrations = $this->_model->fetch_required_migrations($locations, $versions, $default_direction);
+		$db         = $this->_get_db_instance();
 
-		foreach($migrations as $location)
+		foreach($migrations as $path => $location)
 		{
 			$method = $location['direction'] ? 'up' : 'down';
 
@@ -125,7 +167,7 @@ class Minion_Migration_Manager {
 
 				$class = Minion_Migration_Util::get_class_from_migration($migration);
 
-				$this->_db->query(NULL, 'START TRANSACTION');
+				$db->query(NULL, 'START TRANSACTION');
 
 				try
 				{
@@ -133,18 +175,22 @@ class Minion_Migration_Manager {
 
 					$instance = new $class;
 
-					$instance->$method($this->_db);
+					$instance->$method($db);
 				}
 				catch(Exception $e)
 				{
-					$this->_db->query(NULL, 'ROLLBACK');
+					$db->query(NULL, 'ROLLBACK');
 
 					throw $e;
 				}
 				
-				$this->_db->query('COMMIT');
+				$db->query(NULL, 'COMMIT');
 
-				if($record_success)
+				if($this->_dry_run)
+				{
+					$this->_dry_run_sql[$path][$migration['timestamp']] = $db->reset_query_stack();
+				}
+				else
 				{
 					$this->_model->mark_migration($migration, $location['direction']);
 				}
@@ -214,4 +260,20 @@ class Minion_Migration_Manager {
 
 		return Minion_Migration_Util::compile_migrations_from_files($files);
 	}
+
+	/**
+	 * Gets a database connection for running the migrations
+	 *
+	 * @return Kohana_Database Database connection
+	 */
+	protected function _get_db_instance()
+	{
+		// If this isn't a dry run then just use the normal database connection
+		if( ! $this->_dry_run)
+			return $this->_db;
+
+		$db_group = array_search($this->_db, Database::$instances);
+
+		return Minion_Migration_Database::faux_instance($db_group);
+	}
 }

classes/minion/task/db/migrate.php

@@ -40,6 +40,11 @@
  *  No value taken, if this is specified then instead of executing the SQL it 
  *  will be printed to the console
  *
+ * --quiet
+ *
+ *  Suppress all unnessacery output.  If --dry-run is enabled then only dry run 
+ *  SQL will be output
+ *
  * @author Matt Button <matthew@sigswitch.com>
  */
 class Minion_Task_Db_Migrate extends Minion_Task
@@ -59,7 +64,8 @@ class Minion_Task_Db_Migrate extends Minion_Task
 		'environment',
 		'versions',
 		'locations',
-		'dry-run'
+		'dry-run',
+		'quiet'
 	);
 
 	/**
@@ -75,32 +81,33 @@ class Minion_Task_Db_Migrate extends Minion_Task
 		$environment         = Arr::get($config, 'environment', 'development');
 		$specified_locations = Arr::get($config, 'locations',   NULL);
 		$versions            = Arr::get($config, 'versions',    NULL);
-		$dry_run             = isset($config['dry-run']);
+		$dry_run             = array_key_exists('dry-run', $config);
+		$quiet               = array_key_exists('quiet', $config);
 
 		$targets   = $this->_parse_target_versions($versions);
 		$locations = $this->_parse_locations($specified_locations);
 
+		$db_group  = $k_config['db_connections'][$environment];
+		$db        = Database::instance($db_group);
+		$model     = new Model_Minion_Migration($db);
 
-		$db = Database::instance($k_config['db_connections'][$environment]);
+		$manager = new Minion_Migration_Manager($db, $model);
 
-		if($dry_run)
-		{
-			$manager = new Minion_Migration_Manager(
-				Minion_Migration_Database::instance($k_config['db_connections'][$environment]),
-				new Model_Minion_Migration($db)
-			);
-		}
-		else
-		{
-			$manager = new Minion_Migration_Manager($db);
-		}
-
-		$results = $manager
+		$manager
 			// Sync the available migrations with those in the db
 			->sync_migration_files()
-			// Run migrations for specified locations & versions, and if it's 
-			// a dry run don't log results to DB
-			->run_migration($locations, $targets, $this->_default_direction, ! $dry_run);
+
+			->set_dry_run($dry_run)
+
+			// Run migrations for specified locations & versions
+			->run_migration($locations, $targets, $this->_default_direction);
+
+		$view = View::factory('minion/task/db/migrate')
+			->set('dry_run', $dry_run)
+			->set('quiet', $quiet)
+			->set('dry_run_sql', $manager->get_dry_run_sql());
+
+		echo $view;
 	}
 
 	/**

views/minion/task/db/migrate.php

@@ -0,0 +1,31 @@
+<?php if($dry_run): ?>
+<?php if( ! $quiet): ?>
+
+This was a dry run, SQL is as follows:
+<?php endif; ?>
+
+<?php foreach($dry_run_sql as $location => $migrations): ?>
+<?php $location_padding = str_repeat('#', strlen($location)); ?>
+##################<?php echo $location_padding ?>##
+# Begin Location: <?php echo $location; ?> #
+##################<?php echo $location_padding ?>##
+
+<?php foreach($migrations as $timestamp => $sql): ?>
+# Begin <?php echo $timestamp; ?>
+
+<?php foreach($sql as $query): ?>
+
+<?php echo $query;?>;
+<?php endforeach; ?>
+
+# End <?php echo $timestamp; ?>
+
+<?php endforeach; ?>
+
+################<?php echo $location_padding ?>##
+# End Location: <?php echo $location; ?> #
+################<?php echo $location_padding ?>##
+<?php endforeach; ?>
+
+<?php endif; ?>
+