[12.x] Fillable relation as an attribute

Author: DarkGhostHunter

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

@@ -2,6 +2,8 @@
 
 namespace Illuminate\Database\Eloquent\Concerns;
 
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
 trait GuardsAttributes
 {
     /**
@@ -32,6 +34,20 @@ trait GuardsAttributes
      */
     protected static $guardableColumns = [];
 
+    /**
+     * Indicates if filling an attribute named as a Belongs-To relation should be fillable.
+     *
+     * @var bool
+     */
+    public static $fillBelongsToRelations = false;
+
+    /**
+     * The cache for fillable Belongs To Relations methods.
+     *
+     * @var array<class-string<static>,bool>
+     */
+    protected static $fillableBelongsToRelationsCache = [];
+
     /**
      * Get the fillable attributes for the model.
      *
@@ -257,4 +273,19 @@ protected function fillableFromArray(array $attributes)
 
         return $attributes;
     }
+
+    /**
+     * Check if the relation is fillable.
+     *
+     * @param  string  $key
+     * @return bool
+     */
+    protected function isBelongsToFillable($key)
+    {
+        return static::$fillBelongsToRelations
+            && (
+            static::$fillableBelongsToRelationsCache[static::class][$key]
+                ??= $this->isRelation($key) && $this->{$key}() instanceof BelongsTo
+            );
+    }
 }

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

@@ -1052,6 +1052,22 @@ protected function newRelatedThroughInstance($class)
         return new $class;
     }
 
+    /**
+     * Fills a Belongs To relation like it was an attribute value.
+     *
+     * @param  string  $key
+     * @param  \Illuminate\Database\Eloquent\Model $value
+     * @return $this
+     */
+    protected function fillBelongsToRelation($key, $value)
+    {
+        if (!$value->exists) {
+            $value->save();
+        }
+
+        return $this->{$key}()->associate($value);
+    }
+
     /**
      * Get all the loaded relations for the instance.
      *

src/Illuminate/Database/Eloquent/Model.php

@@ -584,7 +584,11 @@ public function fill(array $attributes)
             // which means only those attributes may be set through mass assignment to
             // the model, and all others will just get ignored for security reasons.
             if ($this->isFillable($key)) {
-                $this->setAttribute($key, $value);
+                if ($value instanceof Model && $this->isBelongsToFillable($key)) {
+                    $this->fillBelongsToRelation($key, $value);
+                } else {
+                    $this->setAttribute($key, $value);
+                }
             } elseif ($totallyGuarded || static::preventsSilentlyDiscardingAttributes()) {
                 if (isset(static::$discardedAttributeViolationCallback)) {
                     call_user_func(static::$discardedAttributeViolationCallback, $this, [$key]);

tests/Database/DatabaseEloquentModelTest.php

@@ -68,6 +68,9 @@ protected function tearDown(): void
     {
         parent::tearDown();
 
+        Model::$fillBelongsToRelations = false;
+        EloquentModelStub::$fillBelongsToRelations = false;
+
         m::close();
         Carbon::setTestNow(null);
 
@@ -3330,6 +3333,89 @@ public function testUseFactoryAttribute()
         $this->assertEquals(EloquentModelWithUseFactoryAttribute::class, $factory->modelName());
         $this->assertEquals('test name', $instance->name); // Small smoke test to ensure the factory is working
     }
+
+    public function testFillableWithBelongsToRelationDoesntWorkIfDisabledByDefault()
+    {
+        $model = new EloquentModelStub;
+        $this->addMockConnection($model);
+
+        $model->fillable(['name', 'age']);
+        $relation = new EloquentModelSaveStub();
+        $relation->id = 10;
+
+        $model->fill(['name' => 'foo', 'age' => 'bar', 'belongsToStub' => $relation, 'morphToStub' => $relation]);
+
+        $this->assertNull($model->belongs_to_stub_id);
+        $this->assertNull($model->morph_to_stub_id);
+
+        $model->fillable(['name', 'age', 'belongsToStub', 'morphToStub']);
+        $model->fill(['name' => 'foo', 'age' => 'bar', 'belongsToStub' => $relation, 'morphToStub' => $relation]);
+
+        $this->assertSame('foo', $model->name);
+        $this->assertSame('bar', $model->age);
+        $this->assertNull($model->belongs_to_stub_id);
+        $this->assertNull($model->morph_to_stub_id);
+        $this->assertNull($model->morph_to_stub_type);
+        $this->assertFalse($model->relationLoaded('belongsToStub'));
+        $this->assertFalse($model->relationLoaded('morphToStub'));
+    }
+
+    public function testFillableWithBelongsToRelation()
+    {
+        EloquentModelStub::$fillBelongsToRelations = true;
+
+        $model = new EloquentModelStub;
+        $this->addMockConnection($model);
+
+        $model->fillable(['name', 'age']);
+        $relation = new EloquentModelSaveStub();
+        $relation->id = 10;
+
+        $model->fill(['name' => 'foo', 'age' => 'bar', 'belongsToStub' => $relation, 'morphToStub' => $relation]);
+
+        $this->assertNull($model->belongs_to_stub_id);
+        $this->assertNull($model->morph_to_stub_id);
+
+        $model->fillable(['name', 'age', 'belongsToStub', 'morphToStub']);
+        $model->fill(['name' => 'foo', 'age' => 'bar', 'belongsToStub' => $relation, 'morphToStub' => $relation]);
+
+        $this->assertSame('foo', $model->name);
+        $this->assertSame('bar', $model->age);
+        $this->assertSame(10, $model->belongs_to_stub_id);
+        $this->assertSame(10, $model->morph_to_stub_id);
+        $this->assertSame(EloquentModelSaveStub::class, $model->morph_to_stub_type);
+        $this->assertSAme($relation, $model->getRelation('belongsToStub'));
+        $this->assertSAme($relation, $model->getRelation('morphToStub'));
+    }
+
+    public function testFillableWithBelongsToRelationNotFillableIfDoesntExist()
+    {
+        EloquentModelStub::$fillBelongsToRelations = true;
+
+        $model = new EloquentModelStub;
+        $this->addMockConnection($model);
+        $model->fillable(['name', 'foo']);
+
+        $relation = new EloquentModelSaveStub();
+
+        $model->fill(['foo' => $relation]);
+
+        $this->assertNull($model->getRelation('foo'));
+        $this->assertSame($relation, $model->getAttribute('foo'));
+    }
+
+    public function testFillableWithBelongsToRelationNotModelIsSetAsAttribute()
+    {
+        EloquentModelStub::$fillBelongsToRelations = true;
+
+        $model = new EloquentModelStub;
+        $model->fillable(['name', 'age', 'belongsToStub']);
+
+        $model->fill(['belongsToStub' => 'foo']);
+
+        $this->assertNull($model->getRelation('belongsToStub'));
+        $this->assertSame('foo', $model->getAttribute('belongsToStub'));
+    }
 }
 
 class EloquentTestObserverStub