Merge pull request #225 from patchlevel/copy-connection-for-projection

copy connection for projection

docs/pages/configuration.md

@@ -92,6 +92,30 @@ patchlevel_event_sourcing:
     You can find out more about how to create a connection 
     [here](https://www.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html)
 
+### Connection for Projections
+
+Per default, our event sourcing connection is not available to use in your application.
+But you can create a dedicated connection that you can use for your projections.
+
+```yaml
+patchlevel_event_sourcing:
+  connection:
+    url: '%env(EVENTSTORE_URL)%'
+    provide_dedicated_connection: true
+```
+!!! tip
+
+    You can autowire the connection in your services like this:
+
+    ```php
+    use Doctrine\DBAL\Connection;
+    
+    public function __construct(
+        private readonly Connection $projectionConnection,
+    ) {
+    }
+    ```
+
 ### Doctrine Bundle
 
 If you have installed the [doctrine bundle](https://github.com/doctrine/DoctrineBundle),
@@ -108,6 +132,11 @@ patchlevel_event_sourcing:
     connection:
         service: doctrine.dbal.eventstore_connection
 ```
+!!! danger
+
+    Do not use the same connection for event sourcing and your projections,
+    otherwise you may run into transaction problems.
+
 !!! warning
 
     If you want to use the same connection as doctrine orm, then you have to set the flag `merge_orm_schema`. 
@@ -118,6 +147,42 @@ patchlevel_event_sourcing:
     You can find out more about the dbal configuration 
     [here](https://symfony.com/bundles/DoctrineBundle/current/configuration.html).
 
+If you are using Doctrine for your projections too, you need to create a dedicated connection for this.
+You can do this by defining a new connection named `projection` in the `doctrine.yaml` file
+and use the same connection url as for the event store.
+
+```yaml
+doctrine:
+    dbal:
+        connections:
+            eventstore:
+                url: '%env(EVENTSTORE_URL)%'
+            projection:
+                url: '%env(EVENTSTORE_URL)%'
+
+patchlevel_event_sourcing:
+    connection:
+        service: doctrine.dbal.eventstore_connection
+```
+Then you can use this connection in your projections.
+If you are using autowiring you can inject the right connection `Connection $projectionConnection` parameter name.
+The prefix `projection` is used to identify the connection.
+
+```php
+namespace App\Projection;
+
+use Doctrine\DBAL\Connection;
+use Patchlevel\EventSourcing\Attribute\Projector;
+
+#[Projector('my_projection')]
+class MyProjection
+{
+    public function __construct(
+        private readonly Connection $projectionConnection,
+    ) {
+    }
+}
+```
 ## Store
 
 The store and schema is configurable.
@@ -200,12 +265,12 @@ patchlevel_event_sourcing:
 
     You can find out more about subscriptions in the library 
     [documentation](https://event-sourcing.patchlevel.io/latest/subscription/).
-
+    
 ### Store
 
-You can change where the subscription engine stores its necessary information about the subscription. 
-Default is `dbal`, which means it stores it in the same DB that is used by the dbal event store. 
-Otherwise you also have the option to set it to `in_memory`, then this information will not be persisted anywhere. 
+You can change where the subscription engine stores its necessary information about the subscription.
+Default is `dbal`, which means it stores it in the same DB that is used by the dbal event store.
+Otherwise you also have the option to set it to `in_memory`, then this information will not be persisted anywhere.
 This is very useful for testing. And if that is not enough, you can also define a `custom` store and specify the service.
 
 ```yaml
@@ -215,7 +280,6 @@ patchlevel_event_sourcing:
       type: 'custom' # default is 'dbal'
       service: 'my_subscription_store'
 ```
-
 ### Catch Up
 
 If aggregates are used in the processors and new events are generated there,

docs/pages/getting_started.md

@@ -194,8 +194,9 @@ final class HotelProjection
 {
     use SubscriberUtil;
 
-    public function __construct(private Connection $db)
-    {
+    public function __construct(
+        private Connection $projectionConnection,
+    ) {
     }
 
     /** @return list<array{id: string, name: string, guests: int}> */

docs/pages/installation.md

@@ -36,6 +36,7 @@ patchlevel_event_sourcing:
     events: '%kernel.project_dir%/src'
     connection:
       url: '%env(EVENTSTORE_URL)%'
+      provide_dedicated_connection: true
 
 when@dev:
   patchlevel_event_sourcing:
@@ -63,7 +64,7 @@ EVENTSTORE_URL="pdo-pgsql://app:[email protected]:5432/app?serverVersion=16&c
 !!! note
 
     You can find out more about what a connection url looks like [here](https://www.doctrine-project.org/projects/doctrine-dbal/en/latest/reference/configuration.html#connecting-using-a-url).
-
+    
 ## Database with Docker
 
 If you are using docker, you can use the following `compose.yaml` file to start a postgres database.
@@ -85,7 +86,6 @@ services:
 volumes:
   eventstore_data:
 ```
-
 And for development, you can add a `compose.override.yaml` file to expose the port.
 
 ```yaml
@@ -94,18 +94,16 @@ services:
     ports:
       - "5432"
 ```
-
 ## Symfony CLI
 
-If you are using the [symfony cli](https://symfony.com/download), 
+If you are using the [symfony cli](https://symfony.com/download),
 you can configure that the database is started automatically if you start the server.
 For this you have to add the following configuration to the `.symfony.local.yaml` file.
 
 ```yaml
 workers:
   docker_compose: ~
 ```
-
 !!! success
 
     You have successfully installed the bundle. Now you can start with the [quickstart](./getting_started.md) to get a feeling for the bundle.

src/DependencyInjection/Configuration.php

@@ -28,7 +28,11 @@
  *           },
  *          rebuild_after_file_change: bool
  *      },
- *      connection: ?array{service: ?string, url: ?string},
+ *      connection: ?array{
+ *          service: ?string,
+ *          url: ?string,
+ *          provide_dedicated_connection: bool
+ *      },
  *      store: array{merge_orm_schema: bool, options: array<string, mixed>, type: string, service: ?string},
  *      aggregates: list<string>,
  *      events: list<string>,
@@ -57,6 +61,7 @@ public function getConfigTreeBuilder(): TreeBuilder
                 ->children()
                     ->scalarNode('service')->defaultNull()->end()
                     ->scalarNode('url')->defaultNull()->end()
+                    ->booleanNode('provide_dedicated_connection')->defaultFalse()->end()
                 ->end()
             ->end()
 

src/DependencyInjection/PatchlevelEventSourcingExtension.php

@@ -470,11 +470,25 @@ private function configureConnection(array $config, ContainerBuilder $container)
                     $config['connection']['url'],
                 ]);
 
+            if ($config['connection']['provide_dedicated_connection']) {
+                $container->register('event_sourcing.dbal_public_connection', Connection::class)
+                    ->setFactory([DbalConnectionFactory::class, 'createConnection'])
+                    ->setArguments([
+                        $config['connection']['url'],
+                    ]);
+
+                $container->setAlias(Connection::class, 'event_sourcing.dbal_public_connection');
+            }
+
             return;
         }
 
         if ($config['connection']['service'] === null) {
-            return;
+            throw new InvalidArgumentException('Connection service or url is required');
+        }
+
+        if ($config['connection']['provide_dedicated_connection']) {
+            throw new InvalidArgumentException('Providing dedicated connection is only possible with url');
         }
 
         $container->setAlias('event_sourcing.dbal_connection', $config['connection']['service']);

tests/Unit/PatchlevelEventSourcingBundleTest.php

@@ -152,6 +152,30 @@ public function testConnectionService(): void
         self::assertInstanceOf(DoctrineDbalStore::class, $container->get(Store::class));
     }
 
+    public function testProjectionConnection(): void
+    {
+        $container = new ContainerBuilder();
+        $this->compileContainer(
+            $container,
+            [
+                'patchlevel_event_sourcing' => [
+                    'connection' => [
+                        'url' => 'sqlite3:///:memory:',
+                        'provide_dedicated_connection' => true,
+                    ],
+                ],
+            ]
+        );
+
+        $eventSourcingConnection = $container->get('event_sourcing.dbal_connection');
+        $projectionConnection = $container->get('event_sourcing.dbal_public_connection');
+
+        self::assertInstanceOf(Connection::class, $eventSourcingConnection);
+        self::assertInstanceOf(Connection::class, $projectionConnection);
+
+        self::assertNotSame($eventSourcingConnection, $projectionConnection);
+    }
+
     public function testCustomStore(): void
     {
         $store = $this->prophesize(Store::class)->reveal();