feat: conditionally loads fields

Author: Ark4ne

src/Resources/Concerns/ConditionallyLoadsAttributes.php

@@ -2,11 +2,28 @@
 
 namespace Ark4ne\JsonApi\Resources\Concerns;
 
+use Ark4ne\JsonApi\Support\Fields;
 use Ark4ne\JsonApi\Support\Includes;
 use Illuminate\Http\Request;
 
 trait ConditionallyLoadsAttributes
 {
+    /**
+     * Retrieve a relationship if it has been present in fields.
+     *
+     * @template T
+     *
+     * @param \Illuminate\Http\Request $request
+     * @param string                   $attribute
+     * @param T                        $value
+     *
+     * @return \Illuminate\Http\Resources\MissingValue|T
+     */
+    protected function whenInFields(Request $request, string $attribute, mixed $value)
+    {
+        return $this->when(in_array($attribute, Fields::get($request, $this->toType($request)) ?? [], true), $value);
+    }
+
     /**
      * Retrieve a relationship if it has been included.
      *

tests/Feature/SchemaTest.php

@@ -12,7 +12,7 @@ class SchemaTest extends FeatureTestCase
 {
     public function testSchema()
     {
-        $user = new Skeleton(UserResource::class, 'user', ['name', 'email']);
+        $user = new Skeleton(UserResource::class, 'user', ['name', 'email', 'only-with-fields']);
         $post = new Skeleton(PostResource::class, 'post', ['title', 'content']);
         $comment = new Skeleton(CommentResource::class, 'comment', ['content']);
 

tests/Unit/Resources/Concerns/ConditionallyLoadsAttributesTest.php

@@ -35,4 +35,26 @@ public function testWhenInclude($expected, $property, $query)
             Reflect::invoke($stub, 'whenIncluded', $request, $property, true)
         );
     }
+
+    /**
+     * @dataProvider dataWhenInclude
+     */
+    public function testWhenInFields($expected, $property, $query)
+    {
+        $request = new Request(['fields' => ['type' => implode(',', $query)]]);
+
+        $stub = new class(null) extends JsonResource {
+            use ConditionallyLoadsAttributes;
+
+            protected function toType()
+            {
+                return 'type';
+            }
+        };
+
+        $this->assertEquals(
+            $expected ?: new MissingValue,
+            Reflect::invoke($stub, 'whenInFields', $request, $property, true)
+        );
+    }
 }

tests/app/Http/Resources/UserResource.php

@@ -2,6 +2,7 @@
 
 namespace Test\app\Http\Resources;
 
+use Ark4ne\JsonApi\Resources\Concerns\ConditionallyLoadsAttributes;
 use Ark4ne\JsonApi\Resources\JsonApiResource;
 use DateTimeInterface;
 use Illuminate\Http\Request;
@@ -11,6 +12,8 @@
  */
 class UserResource extends JsonApiResource
 {
+    use ConditionallyLoadsAttributes;
+
     protected function toType(Request $request): string
     {
         return 'user';
@@ -21,6 +24,7 @@ protected function toAttributes(Request $request): iterable
         return [
             'name' => $this->resource->name,
             'email' => $this->resource->email,
+            'only-with-fields' => $this->whenInFields($request, 'only-with-fields', fn() => 'huge-data-set'),
         ];
     }