[8.x] Add custom pagination information in resource (#39600)

* add custom pagination information in resource

* Update PaginatedResourceResponse.php

Co-authored-by: Taylor Otwell <taylor@laravel.com>

src/Illuminate/Http/Resources/Json/PaginatedResourceResponse.php

@@ -43,10 +43,16 @@ protected function paginationInformation($request)
     {
         $paginated = $this->resource->resource->toArray();
 
-        return [
+        $default = [
             'links' => $this->paginationLinks($paginated),
             'meta' => $this->meta($paginated),
         ];
+
+        if (method_exists($this->resource, 'paginationInformation')) {
+            return $this->resource->paginationInformation($request, $paginated, $default);
+        }
+
+        return $default;
     }
 
     /**

tests/Integration/Http/Fixtures/AnonymousResourceCollectionWithPaginationInformation.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Http\Fixtures;
+
+use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
+
+class AnonymousResourceCollectionWithPaginationInformation extends AnonymousResourceCollection
+{
+    public function paginationInformation($request)
+    {
+        $paginated = $this->resource->toArray();
+
+        return [
+            'current_page' => $paginated['current_page'],
+            'per_page' => $paginated['per_page'],
+            'total' => $paginated['total'],
+            'total_page' => $paginated['last_page'],
+        ];
+    }
+}

tests/Integration/Http/Fixtures/PostCollectionResourceWithPaginationInformation.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Http\Fixtures;
+
+use Illuminate\Http\Resources\Json\ResourceCollection;
+
+class PostCollectionResourceWithPaginationInformation extends ResourceCollection
+{
+    public $collects = PostResource::class;
+
+    public function toArray($request)
+    {
+        return ['data' => $this->collection];
+    }
+
+    public function paginationInformation($request)
+    {
+        $paginated = $this->resource->toArray();
+
+        return [
+            'current_page' => $paginated['current_page'],
+            'per_page' => $paginated['per_page'],
+            'total' => $paginated['total'],
+            'total_page' => $paginated['last_page'],
+        ];
+    }
+}

tests/Integration/Http/Fixtures/PostResourceWithAnonymousResourceCollectionWithPaginationInformation.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace Illuminate\Tests\Integration\Http\Fixtures;
+
+use Illuminate\Http\Resources\Json\JsonResource;
+
+class PostResourceWithAnonymousResourceCollectionWithPaginationInformation extends JsonResource
+{
+    public function toArray($request)
+    {
+        return ['id' => $this->id, 'title' => $this->title, 'custom' => true];
+    }
+
+    /**
+     * Create a new anonymous resource collection.
+     *
+     * @param  mixed  $resource
+     * @return AnonymousResourceCollectionWithPaginationInformation
+     */
+    public static function collection($resource)
+    {
+        return tap(new AnonymousResourceCollectionWithPaginationInformation($resource, static::class), function ($collection) {
+            if (property_exists(static::class, 'preserveKeys')) {
+                $collection->preserveKeys = (new static([]))->preserveKeys === true;
+            }
+        });
+    }
+}

tests/Integration/Http/ResourceTest.php

@@ -20,7 +20,9 @@
 use Illuminate\Tests\Integration\Http\Fixtures\ObjectResource;
 use Illuminate\Tests\Integration\Http\Fixtures\Post;
 use Illuminate\Tests\Integration\Http\Fixtures\PostCollectionResource;
+use Illuminate\Tests\Integration\Http\Fixtures\PostCollectionResourceWithPaginationInformation;
 use Illuminate\Tests\Integration\Http\Fixtures\PostResource;
+use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithAnonymousResourceCollectionWithPaginationInformation;
 use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithExtraData;
 use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithOptionalAppendedAttributes;
 use Illuminate\Tests\Integration\Http\Fixtures\PostResourceWithOptionalData;
@@ -885,6 +887,68 @@ public function testOriginalOnResponseIsCollectionOfModelWhenCollectionResource(
         });
     }
 
+    public function testCollectionResourceWithPaginationInfomation()
+    {
+        $posts = collect([
+            new Post(['id' => 5, 'title' => 'Test Title']),
+        ]);
+
+        Route::get('/', function () use ($posts) {
+            return new PostCollectionResourceWithPaginationInformation(new LengthAwarePaginator($posts, 10, 1, 1));
+        });
+
+        $response = $this->withoutExceptionHandling()->get(
+            '/',
+            ['Accept' => 'application/json']
+        );
+
+        $response->assertStatus(200);
+
+        $response->assertJson([
+            'data' => [
+                [
+                    'id' => 5,
+                    'title' => 'Test Title',
+                ],
+            ],
+            'current_page' => 1,
+            'per_page' => 1,
+            'total_page' => 10,
+            'total' => 10,
+        ]);
+    }
+
+    public function testResourceWithPaginationInfomation()
+    {
+        $posts = collect([
+            new Post(['id' => 5, 'title' => 'Test Title']),
+        ]);
+
+        Route::get('/', function () use ($posts) {
+            return PostResourceWithAnonymousResourceCollectionWithPaginationInformation::collection(new LengthAwarePaginator($posts, 10, 1, 1));
+        });
+
+        $response = $this->withoutExceptionHandling()->get(
+            '/',
+            ['Accept' => 'application/json']
+        );
+
+        $response->assertStatus(200);
+
+        $response->assertJson([
+            'data' => [
+                [
+                    'id' => 5,
+                    'title' => 'Test Title',
+                ],
+            ],
+            'current_page' => 1,
+            'per_page' => 1,
+            'total_page' => 10,
+            'total' => 10,
+        ]);
+    }
+
     public function testCollectionResourcesAreCountable()
     {
         $posts = collect([