Add Defer Prop

src/DeferProp.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace Inertia;
+
+use Illuminate\Support\Facades\App;
+
+class DeferProp extends LazyProp
+{
+}

src/Inertia.php

@@ -12,6 +12,7 @@
  * @method static void version(\Closure|string|null $version)
  * @method static string getVersion()
  * @method static \Inertia\LazyProp lazy(callable $callback)
+ * @method static \Inertia\DeferProp defer(callable $callback)
  * @method static \Inertia\Response render(string $component, array|\Illuminate\Contracts\Support\Arrayable $props = [])
  * @method static \Symfony\Component\HttpFoundation\Response location(string|\Symfony\Component\HttpFoundation\RedirectResponse $url)
  * @method static void macro(string $name, object|callable $macro)

src/Response.php

@@ -87,13 +87,18 @@ public function rootView(string $rootView): self
     public function toResponse($request)
     {
         $only = array_filter(explode(',', $request->header('X-Inertia-Partial-Data', '')));
+        $isPartial = ($only && $request->header('X-Inertia-Partial-Component') === $this->component);
 
-        $props = ($only && $request->header('X-Inertia-Partial-Component') === $this->component)
+        $props = $isPartial
             ? Arr::only($this->props, $only)
             : array_filter($this->props, static function ($prop) {
-                return ! ($prop instanceof LazyProp);
+                return ! ($prop instanceof LazyProp || $prop instanceof DeferProp);
             });
 
+        $deferProps = $isPartial ? [] : array_filter($this->props, static function ($prop) {
+            return $prop instanceof DeferProp;
+        });
+
         $props = $this->resolvePropertyInstances($props, $request);
 
         $page = [
@@ -103,6 +108,10 @@ public function toResponse($request)
             'version' => $this->version,
         ];
 
+        if (!empty($deferProps)) {
+            $page['deferProps'] = array_keys($deferProps);
+        }
+
         if ($request->header('X-Inertia')) {
             return new JsonResponse($page, 200, ['X-Inertia' => 'true']);
         }
@@ -120,7 +129,7 @@ public function resolvePropertyInstances(array $props, Request $request, bool $u
                 $value = App::call($value);
             }
 
-            if ($value instanceof LazyProp) {
+            if ($value instanceof LazyProp || $value instanceof DeferProp) {
                 $value = App::call($value);
             }
 

src/ResponseFactory.php

@@ -87,6 +87,11 @@ public function lazy(callable $callback): LazyProp
         return new LazyProp($callback);
     }
 
+    public function defer(callable $callback): DeferProp
+    {
+        return new DeferProp($callback);
+    }
+
     /**
      * @param array|Arrayable $props
      */

tests/DeferPropTest.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Inertia\Tests;
+
+use Illuminate\Http\Request;
+use Inertia\DeferProp;
+
+class DeferPropTest extends TestCase
+{
+    public function test_can_invoke(): void
+    {
+        $deferProp = new DeferProp(function () {
+            return 'A deferred value';
+        });
+
+        $this->assertSame('A deferred value', $deferProp());
+    }
+
+    public function test_can_resolve_bindings_when_invoked(): void
+    {
+        $deferProp = new DeferProp(function (Request $request) {
+            return $request;
+        });
+
+        $this->assertInstanceOf(Request::class, $deferProp());
+    }
+}

tests/ResponseFactoryTest.php

@@ -13,6 +13,7 @@
 use Illuminate\Contracts\Support\Arrayable;
 use Illuminate\Http\Request as HttpRequest;
 use Illuminate\Session\Middleware\StartSession;
+use Inertia\DeferProp;
 use Illuminate\Session\NullSessionHandler;
 use Illuminate\Session\Store;
 
@@ -160,12 +161,22 @@ public function test_can_create_lazy_prop(): void
         $this->assertInstanceOf(LazyProp::class, $lazyProp);
     }
 
+    public function test_can_create_defer_prop(): void
+    {
+        $factory = new ResponseFactory();
+        $deferProp = $factory->defer(function () {
+            return 'A deferred value';
+        });
+
+        $this->assertInstanceOf(DeferProp::class, $deferProp);
+    }
+
     public function test_will_accept_arrayabe_props()
     {
         Route::middleware([StartSession::class, ExampleMiddleware::class])->get('/', function () {
             Inertia::share('foo', 'bar');
 
-            return Inertia::render('User/Edit', new class() implements Arrayable {
+            return Inertia::render('User/Edit', new class () implements Arrayable {
                 public function toArray()
                 {
                     return [

tests/ResponseTest.php

@@ -15,6 +15,7 @@
 use Illuminate\Pagination\LengthAwarePaginator;
 use Illuminate\Http\Resources\Json\JsonResource;
 use Illuminate\Http\Resources\Json\ResourceCollection;
+use Inertia\DeferProp;
 
 class ResponseTest extends TestCase
 {
@@ -97,7 +98,7 @@ public function test_lazy_resource_response(): void
         $callable = static function () use ($users) {
             $page = new LengthAwarePaginator($users->take(2), $users->count(), 2);
 
-            return new class($page, JsonResource::class) extends ResourceCollection {
+            return new class ($page, JsonResource::class) extends ResourceCollection {
             };
         };
 
@@ -151,7 +152,7 @@ public function test_nested_lazy_resource_response(): void
 
             // nested array with ResourceCollection to resolve
             return [
-                'users' => new class($page, JsonResource::class) extends ResourceCollection {},
+                'users' => new class ($page, JsonResource::class) extends ResourceCollection {},
             ];
         };
 
@@ -272,6 +273,24 @@ public function test_lazy_props_are_not_included_by_default(): void
         $this->assertFalse(property_exists($page->props, 'lazy'));
     }
 
+    public function test_defer_props_are_not_included_by_default(): void
+    {
+        $request = Request::create('/users', 'GET');
+        $request->headers->add(['X-Inertia' => 'true']);
+
+        $deferProp = new DeferProp(function () {
+            return 'A defer value';
+        });
+
+        $response = new Response('Users', ['users' => [], 'defer' => $deferProp], 'app', '123');
+        $response = $response->toResponse($request);
+        $page = $response->getData();
+
+        $this->assertSame([], $page->props->users);
+        $this->assertSame(['defer'], $page->deferProps);
+        $this->assertFalse(property_exists($page->props, 'defer'));
+    }
+
     public function test_lazy_props_are_included_in_partial_reload(): void
     {
         $request = Request::create('/users', 'GET');
@@ -291,6 +310,25 @@ public function test_lazy_props_are_included_in_partial_reload(): void
         $this->assertSame('A lazy value', $page->props->lazy);
     }
 
+    public function test_defer_props_are_included_in_partial_reload(): void
+    {
+        $request = Request::create('/users', 'GET');
+        $request->headers->add(['X-Inertia' => 'true']);
+        $request->headers->add(['X-Inertia-Partial-Component' => 'Users']);
+        $request->headers->add(['X-Inertia-Partial-Data' => 'defer']);
+
+        $deferProp = new DeferProp(function () {
+            return 'A deferred value';
+        });
+
+        $response = new Response('Users', ['users' => [], 'defer' => $deferProp], 'app', '123');
+        $response = $response->toResponse($request);
+        $page = $response->getData();
+
+        $this->assertFalse(property_exists($page->props, 'users'));
+        $this->assertSame('A deferred value', $page->props->defer);
+    }
+
     public function test_top_level_dot_props_get_unpacked(): void
     {
         $props = [