Add event_class_map for event class aliases

docs/advanced-usage/using-aliases-for-stored-event-classes.md

@@ -0,0 +1,21 @@
+---
+title: Using aliases for stored event classes
+weight: 8
+---
+
+By default we store the `Event`'s FQN in the database when storing the events. This prevents you from changing the name or the namespace of your event classes.
+
+To get around this you can define event class aliases in the `event-projector.php` config file:
+
+```php
+    /*
+     * Similar to Relation::morphMap() you can define which alias responds to which
+     * event class. This allows you to change the namespace or classnames
+     * of your events but still handle older events correctly.
+     */
+    'event_class_map' => [
+        'money_added' => MoneyAddedEvent::class,
+    ],
+```
+
+With this configuration, instead of saving `\App\Events\MoneyAddedEvent` in the database, we just store `money_added`, now you can change the event classname and namespace. Just make sure to also change the mapping!

src/Models/StoredEvent.php

@@ -28,7 +28,7 @@ public static function createForEvent(ShouldBeStored $event, string $uuid = null
     {
         $storedEvent = new static();
         $storedEvent->aggregate_uuid = $uuid;
-        $storedEvent->event_class = self::getEventClass(get_class($event));
+        $storedEvent->event_class = static::getEventClass(get_class($event));
         $storedEvent->attributes['event_properties'] = app(EventSerializer::class)->serialize(clone $event);
         $storedEvent->meta_data = [];
         $storedEvent->created_at = Carbon::now();
@@ -38,9 +38,9 @@ public static function createForEvent(ShouldBeStored $event, string $uuid = null
         return $storedEvent;
     }
 
-    public function getEventClassAttribute(string $value): string
+    public static function getEventClassAttribute(string $value): string
     {
-        return self::getActualClassForEvent($value);
+        return static::getActualClassForEvent($value);
     }
 
     public function getEventAttribute(): ShouldBeStored
@@ -107,7 +107,7 @@ public static function store(ShouldBeStored $event, string $uuid = null): void
         static::storeMany([$event], $uuid);
     }
 
-    private static function getEventClass(string $class): string
+    protected static function getEventClass(string $class): string
     {
         $map = config('event-projector.event_class_map', []);
 
@@ -118,7 +118,7 @@ private static function getEventClass(string $class): string
         return $class;
     }
 
-    private static function getActualClassForEvent(string $class): string
+    protected static function getActualClassForEvent(string $class): string
     {
         return Arr::get(config('event-projector.event_class_map', []), $class, $class);
     }