feat: dispatch transactions events

cc cycle#96

src/Driver/Driver.php

@@ -16,6 +16,9 @@
 use Cycle\Database\Config\PDOConnectionConfig;
 use Cycle\Database\Config\ProvidesSourceString;
 use Cycle\Database\Event\QueryExecuted;
+use Cycle\Database\Event\TransactionBeginning;
+use Cycle\Database\Event\TransactionCommited;
+use Cycle\Database\Event\TransactionRolledBack;
 use Cycle\Database\EventDispatcherAwareInterface;
 use Cycle\Database\EventDispatcherAwareTrait;
 use Cycle\Database\Exception\DriverException;
@@ -321,6 +324,15 @@ public function getTransactionLevel(): int
      * @param string|null $isolationLevel
      */
     public function beginTransaction(string $isolationLevel = null): bool
+    {
+        $transactionCreated = $this->createTransaction($isolationLevel);
+
+        $this->eventDispatcher?->dispatch(new TransactionBeginning($this));
+
+        return $transactionCreated;
+    }
+
+    protected function createTransaction(string $isolationLevel = null): bool
     {
         ++$this->transactionLevel;
 
@@ -391,14 +403,20 @@ public function commitTransaction(): bool
             $this->logger?->info('Commit transaction');
 
             try {
-                return $this->getPDO()->commit();
+                $transactionCommited = $this->getPDO()->commit();
+
+                $this->eventDispatcher?->dispatch(new TransactionCommited($this));
+
+                return $transactionCommited;
             } catch (Throwable $e) {
                 throw $this->mapException($e, 'COMMIT TRANSACTION');
             }
         }
 
         $this->releaseSavepoint($this->transactionLevel + 1);
 
+        $this->eventDispatcher?->dispatch(new TransactionCommited($this));
+
         return true;
     }
 
@@ -436,6 +454,8 @@ public function rollbackTransaction(): bool
 
         $this->rollbackSavepoint($this->transactionLevel + 1);
 
+        $this->eventDispatcher?->dispatch(new TransactionRolledBack($this));
+
         return true;
     }
 

src/Driver/Postgres/PostgresDriver.php

@@ -19,6 +19,7 @@
 use Cycle\Database\Driver\Postgres\Query\PostgresInsertQuery;
 use Cycle\Database\Driver\Postgres\Query\PostgresSelectQuery;
 use Cycle\Database\Driver\Postgres\Query\PostgresUpdateQuery;
+use Cycle\Database\Event\TransactionBeginning;
 use Cycle\Database\Exception\DriverException;
 use Cycle\Database\Exception\StatementException;
 use Cycle\Database\Query\QueryBuilder;
@@ -130,18 +131,7 @@ public function resetPrimaryKeys(): void
         $this->primaryKeys = [];
     }
 
-    /**
-     * Start SQL transaction with specified isolation level (not all DBMS support it). Nested
-     * transactions are processed using savepoints.
-     *
-     * @link http://en.wikipedia.org/wiki/Database_transaction
-     * @link http://en.wikipedia.org/wiki/Isolation_(database_systems)
-     *
-     * @param string|null $isolationLevel
-     *
-     * @return bool
-     */
-    public function beginTransaction(string $isolationLevel = null): bool
+    protected function createTransaction(string $isolationLevel = null): bool
     {
         ++$this->transactionLevel;
 

src/Event/AbstractDriverEvent.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Cycle\Database\Event;
+
+use Cycle\Database\Driver\DriverInterface;
+
+abstract class AbstractDriverEvent
+{
+    public function __construct(
+        public readonly DriverInterface $driver,
+    ) {
+    }
+}

src/Event/QueryExecuted.php

@@ -4,14 +4,15 @@
 
 use Cycle\Database\Driver\DriverInterface;
 
-class QueryExecuted
+final class QueryExecuted extends AbstractDriverEvent
 {
     public function __construct(
         public readonly string $query,
         public readonly array $params,
         public readonly float $queryStart,
         public readonly float $queryEnd,
-        public readonly DriverInterface $driver,
+        DriverInterface $driver,
     ) {
+        parent::__construct($driver);
     }
 }

src/Event/TransactionBeginning.php

@@ -0,0 +1,10 @@
+<?php
+
+namespace Cycle\Database\Event;
+
+use Cycle\Database\Event\AbstractDriverEvent;
+
+class TransactionBeginning extends AbstractDriverEvent
+{
+
+}

src/Event/TransactionCommited.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Cycle\Database\Event;
+
+class TransactionCommited extends AbstractDriverEvent
+{
+
+}

src/Event/TransactionRolledBack.php

@@ -0,0 +1,8 @@
+<?php
+
+namespace Cycle\Database\Event;
+
+class TransactionRolledBack extends AbstractDriverEvent
+{
+
+}

src/EventDispatcherAwareTrait.php

@@ -6,7 +6,7 @@
 
 trait EventDispatcherAwareTrait
 {
-    private ?EventDispatcherInterface $eventDispatcher = null;
+    protected ?EventDispatcherInterface $eventDispatcher = null;
 
     public function setEventDispatcher(EventDispatcherInterface $eventDispatcher): void
     {