[12.x] Fix support for adding custom observable events from traits

src/Illuminate/Database/Eloquent/Concerns/HasEvents.php

@@ -38,7 +38,7 @@ trait HasEvents
      */
     public static function bootHasEvents()
     {
-        static::observe(static::resolveObserveAttributes());
+        static::whenBooted(fn () => static::observe(static::resolveObserveAttributes()));
     }
 
     /**

src/Illuminate/Database/Eloquent/Model.php

@@ -3,6 +3,7 @@
 namespace Illuminate\Database\Eloquent;
 
 use ArrayAccess;
+use Closure;
 use Illuminate\Contracts\Broadcasting\HasBroadcastChannel;
 use Illuminate\Contracts\Queue\QueueableCollection;
 use Illuminate\Contracts\Queue\QueueableEntity;
@@ -150,6 +151,13 @@ abstract class Model implements Arrayable, ArrayAccess, CanBeEscapedWhenCastToSt
      */
     protected static $booted = [];
 
+    /**
+     * The callbacks that should be executed after the model has booted.
+     *
+     * @var array
+     */
+    protected static $bootedCallbacks = [];
+
     /**
      * The array of trait initializers that will be called on each new instance.
      *
@@ -280,6 +288,12 @@ protected function bootIfNotBooted()
             static::boot();
             static::booted();
 
+            static::$bootedCallbacks[static::class] ??= [];
+
+            foreach (static::$bootedCallbacks[static::class] as $callback) {
+                $callback();
+            }
+
             $this->fireModelEvent('booted', false);
         }
     }
@@ -358,6 +372,19 @@ protected static function booted()
         //
     }
 
+    /**
+     * Register a closure to be executed after the model has booted.
+     *
+     * @param  \Closure  $callback
+     * @return void
+     */
+    protected static function whenBooted(Closure $callback)
+    {
+        static::$bootedCallbacks[static::class] ??= [];
+
+        static::$bootedCallbacks[static::class][] = $callback;
+    }
+
     /**
      * Clear the list of booted models so they will be re-booted.
      *
@@ -366,6 +393,7 @@ protected static function booted()
     public static function clearBootedModels()
     {
         static::$booted = [];
+        static::$bootedCallbacks = [];
 
         static::$globalScopes = [];
     }

tests/Database/DatabaseEloquentModelTest.php

@@ -2293,6 +2293,35 @@ public function testModelIsBootedOnUnserialize()
         $this->assertTrue(EloquentModelBootingTestStub::isBooted());
     }
 
+    public function testCallbacksCanBeRunAfterBootingHasFinished()
+    {
+        $this->assertFalse(EloquentModelBootingCallbackTestStub::$bootHasFinished);
+
+        $model = new EloquentModelBootingCallbackTestStub();
+
+        $this->assertTrue($model::$bootHasFinished);
+
+        EloquentModelBootingCallbackTestStub::unboot();
+    }
+
+    public function testBootedCallbacksAreSeparatedByClass()
+    {
+        $this->assertFalse(EloquentModelBootingCallbackTestStub::$bootHasFinished);
+
+        $model = new EloquentModelBootingCallbackTestStub();
+
+        $this->assertTrue($model::$bootHasFinished);
+
+        $this->assertFalse(EloquentChildModelBootingCallbackTestStub::$bootHasFinished);
+
+        $model = new EloquentChildModelBootingCallbackTestStub();
+
+        $this->assertTrue($model::$bootHasFinished);
+
+        EloquentModelBootingCallbackTestStub::unboot();
+        EloquentChildModelBootingCallbackTestStub::unboot();
+    }
+
     public function testModelsTraitIsInitialized()
     {
         $model = new EloquentModelStubWithTrait;
@@ -3602,6 +3631,7 @@ class EloquentModelBootingTestStub extends Model
     public static function unboot()
     {
         unset(static::$booted[static::class]);
+        unset(static::$bootedCallbacks[static::class]);
     }
 
     public static function isBooted()
@@ -4121,3 +4151,30 @@ class EloquentModelWithUseFactoryAttribute extends Model
 {
     use HasFactory;
 }
+
+trait EloquentTraitBootingCallbackTestStub
+{
+    public static function bootEloquentTraitBootingCallbackTestStub()
+    {
+        static::whenBooted(fn () => static::$bootHasFinished = true);
+    }
+}
+
+class EloquentModelBootingCallbackTestStub extends Model
+{
+    use EloquentTraitBootingCallbackTestStub;
+
+    public static bool $bootHasFinished = false;
+
+    public static function unboot()
+    {
+        unset(static::$booted[static::class]);
+        unset(static::$bootedCallbacks[static::class]);
+        static::$bootHasFinished = false;
+    }
+}
+
+class EloquentChildModelBootingCallbackTestStub extends EloquentModelBootingCallbackTestStub
+{
+    public static bool $bootHasFinished = false;
+}

tests/Integration/Database/EloquentModelCustomEventsTest.php

@@ -2,6 +2,7 @@
 
 namespace Illuminate\Tests\Integration\Database\EloquentModelCustomEventsTest;
 
+use Illuminate\Database\Eloquent\Attributes\ObservedBy;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Schema\Blueprint;
 use Illuminate\Support\Facades\Event;
@@ -24,6 +25,11 @@ protected function afterRefreshingDatabase()
         Schema::create('test_model1', function (Blueprint $table) {
             $table->increments('id');
         });
+
+        Schema::create('eloquent_model_stub_with_custom_event_from_traits', function (Blueprint $table) {
+            $table->boolean('custom_attribute');
+            $table->boolean('observer_attribute');
+        });
     }
 
     public function testFlushListenersClearsCustomEvents()
@@ -45,6 +51,19 @@ public function testCustomEventListenersAreFired()
 
         $this->assertTrue($_SERVER['fired_event']);
     }
+
+    public function testAddObservableEventFromTrait()
+    {
+        $model = new EloquentModelStubWithCustomEventFromTrait();
+
+        $this->assertNull($model->custom_attribute);
+        $this->assertNull($model->observer_attribute);
+
+        $model->completeCustomAction();
+
+        $this->assertTrue($model->custom_attribute);
+        $this->assertTrue($model->observer_attribute);
+    }
 }
 
 class TestModel1 extends Model
@@ -59,3 +78,36 @@ class CustomEvent
 {
     //
 }
+
+trait CustomEventTrait
+{
+    public function completeCustomAction()
+    {
+        $this->custom_attribute = true;
+
+        $this->fireModelEvent('customEvent');
+    }
+
+    public function initializeCustomEventTrait()
+    {
+        $this->addObservableEvents([
+            'customEvent',
+        ]);
+    }
+}
+
+class CustomObserver
+{
+    public function customEvent(EloquentModelStubWithCustomEventFromTrait $model)
+    {
+        $model->observer_attribute = true;
+    }
+}
+
+#[ObservedBy(CustomObserver::class)]
+class EloquentModelStubWithCustomEventFromTrait extends Model
+{
+    use CustomEventTrait;
+
+    public $timestamps = false;
+}