图1
1、在 Laravel 6 中，当网址不存在时，期望响应 404 时，最终响应 500。如图1
detail:Undefined variable: page (View: ) (View: ) {"exception":"[object] (Illuminate\\View\\ViewException(code: 0): Undefined variable: page (View: ) (View: ) at object/storage/framework/views/cc0fa0095d11c7b735d528a4910ade17b0a8b9e6.php:84)
[stacktrace]
#0 object/vendor/laravel/framework/src/Illuminate/View/Engines/PhpEngine.php(45): Illuminate\\View\\Engines\\CompilerEngine->handleViewException(Object(Illuminate\\View\\ViewException), 0)
#1 object/vendor/laravel/framework/src/Illuminate/View/Engines/CompilerEngine.php(59): Illuminate\\View\\Engines\\PhpEngine->evaluatePath('object/...', Array)
#2 object/vendor/laravel/framework/src/Illuminate/View/View.php(143): Illuminate\\View\\Engines\\CompilerEngine->get('errors/404.blad...', Array)
#3 object/vendor/laravel/framework/src/Illuminate/View/View.php(126): Illuminate\\View\\View->getContents()
#4 object/vendor/laravel/framework/src/Illuminate/View/View.php(91): Illuminate\\View\\View->renderContents()
#5 object/vendor/laravel/framework/src/Illuminate/Http/Response.php(42): Illuminate\\View\\View->render()
#6 object/vendor/symfony/http-foundation/Response.php(205): Illuminate\\Http\\Response->setContent(Object(Modules\\View\\View))
#7 object/vendor/laravel/framework/src/Illuminate/Routing/ResponseFactory.php(55): Symfony\\Component\\HttpFoundation\\Response->__construct(Object(Modules\\View\\View), 404, Array)
#8 object/vendor/laravel/framework/src/Illuminate/Routing/ResponseFactory.php(85): Illuminate\\Routing\\ResponseFactory->make(Object(Modules\\View\\View), 404, Array)
#9 object/app/Http/Controllers/Controller.php(43): Illuminate\\Routing\\ResponseFactory->view('errors.404', Array, 404)
#10 object/app/Http/Controllers/PageController.php(29): App\\Http\\Controllers\\Controller->fallback()
#11 object/vendor/laravel/framework/src/Illuminate/Routing/Controller.php(54): App\\Http\\Controllers\\PageController->index('(SELECT (CASE W...')
#12 object/vendor/laravel/framework/src/Illuminate/Routing/ControllerDispatcher.php(45): Illuminate\\Routing\\Controller->callAction('index', Array)
#13 object/vendor/laravel/framework/src/Illuminate/Routing/Route.php(219): Illuminate\\Routing\\ControllerDispatcher->dispatch(Object(Illuminate\\Routing\\Route), Object(App\\Http\\Controllers\\PageController), 'index')
#14 object/vendor/laravel/framework/src/Illuminate/Routing/Route.php(176): Illuminate\\Routing\\Route->runController()
#15 object/vendor/laravel/framework/src/Illuminate/Routing/Router.php(681): Illuminate\\Routing\\Route->run()
#16 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(130): Illuminate\\Routing\\Router->Illuminate\\Routing\\{closure}(Object(Illuminate\\Http\\Request))
#17 object/vendor/silber/page-cache/src/Middleware/CacheResponse.php(38): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#18 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Silber\\PageCache\\Middleware\\CacheResponse->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#19 object/app/Http/Middleware/SeoRedirectMiddleware.php(30): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#20 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\SeoRedirectMiddleware->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#21 object/app/Http/Middleware/FacebookSwitch.php(21): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#22 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\FacebookSwitch->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#23 object/app/Http/Middleware/CheckStoreStatus.php(37): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#24 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\CheckStoreStatus->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#25 object/app/Http/Middleware/PasswordProtected.php(66): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#26 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\PasswordProtected->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#27 object/app/Http/Middleware/FallbackToFileViewStorage.php(35): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#28 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\FallbackToFileViewStorage->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#29 object/app/Http/Middleware/DetectLanguage.php(26): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#30 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\DetectLanguage->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#31 object/app/Http/Middleware/ActivateTheme.php(22): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#32 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\ActivateTheme->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#33 object/app/Http/Middleware/ConfigTheme.php(79): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#34 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\ConfigTheme->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#35 object/vendor/laravel/framework/src/Illuminate/Routing/Middleware/SubstituteBindings.php(41): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#36 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Illuminate\\Routing\\Middleware\\SubstituteBindings->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#37 object/app/Http/Middleware/SwitchDomain.php(58): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#38 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\SwitchDomain->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#39 object/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/VerifyCsrfToken.php(78): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#40 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Illuminate\\Foundation\\Http\\Middleware\\VerifyCsrfToken->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#41 object/vendor/laravel/framework/src/Illuminate/View/Middleware/ShareErrorsFromSession.php(49): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#42 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Illuminate\\View\\Middleware\\ShareErrorsFromSession->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#43 object/vendor/laravel/framework/src/Illuminate/Session/Middleware/StartSession.php(56): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#44 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Illuminate\\Session\\Middleware\\StartSession->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#45 object/vendor/laravel/framework/src/Illuminate/Cookie/Middleware/AddQueuedCookiesToResponse.php(37): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#46 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Illuminate\\Cookie\\Middleware\\AddQueuedCookiesToResponse->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#47 object/vendor/laravel/framework/src/Illuminate/Cookie/Middleware/EncryptCookies.php(67): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#48 object/app/Http/Middleware/EncryptCookies.php(30): Illuminate\\Cookie\\Middleware\\EncryptCookies->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#49 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\EncryptCookies->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#50 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(105): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#51 object/vendor/laravel/framework/src/Illuminate/Routing/Router.php(683): Illuminate\\Pipeline\\Pipeline->then(Object(Closure))
#52 object/vendor/laravel/framework/src/Illuminate/Routing/Router.php(658): Illuminate\\Routing\\Router->runRouteWithinStack(Object(Illuminate\\Routing\\Route), Object(Illuminate\\Http\\Request))
#53 object/vendor/laravel/framework/src/Illuminate/Routing/Router.php(624): Illuminate\\Routing\\Router->runRoute(Object(Illuminate\\Http\\Request), Object(Illuminate\\Routing\\Route))
#54 object/vendor/laravel/framework/src/Illuminate/Routing/Router.php(613): Illuminate\\Routing\\Router->dispatchToRoute(Object(Illuminate\\Http\\Request))
#55 object/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(170): Illuminate\\Routing\\Router->dispatch(Object(Illuminate\\Http\\Request))
#56 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(130): Illuminate\\Foundation\\Http\\Kernel->Illuminate\\Foundation\\Http\\{closure}(Object(Illuminate\\Http\\Request))
#57 object/app/Http/Middleware/ChangeAppUrlMiddleware.php(23): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#58 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): App\\Http\\Middleware\\ChangeAppUrlMiddleware->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#59 object/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TransformsRequest.php(21): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#60 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#61 object/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/TransformsRequest.php(21): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#62 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Illuminate\\Foundation\\Http\\Middleware\\TransformsRequest->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#63 object/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/ValidatePostSize.php(27): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#64 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Illuminate\\Foundation\\Http\\Middleware\\ValidatePostSize->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#65 object/vendor/laravel/framework/src/Illuminate/Foundation/Http/Middleware/CheckForMaintenanceMode.php(63): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#66 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Illuminate\\Foundation\\Http\\Middleware\\CheckForMaintenanceMode->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#67 object/vendor/fideloper/proxy/src/TrustProxies.php(57): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#68 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Fideloper\\Proxy\\TrustProxies->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#69 object/vendor/dingo/api/src/Http/Middleware/Request.php(111): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#70 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(171): Dingo\\Api\\Http\\Middleware\\Request->handle(Object(Illuminate\\Http\\Request), Object(Closure))
#71 object/vendor/laravel/framework/src/Illuminate/Pipeline/Pipeline.php(105): Illuminate\\Pipeline\\Pipeline->Illuminate\\Pipeline\\{closure}(Object(Illuminate\\Http\\Request))
#72 object/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(145): Illuminate\\Pipeline\\Pipeline->then(Object(Closure))
#73 object/vendor/laravel/framework/src/Illuminate/Foundation/Http/Kernel.php(110): Illuminate\\Foundation\\Http\\Kernel->sendRequestThroughRouter(Object(Illuminate\\Http\\Request))
#74 object/public/index.php(57): Illuminate\\Foundation\\Http\\Kernel->handle(Object(Illuminate\\Http\\Request))
#75 {main}
2、打开网址：https://object.local/pages/ce-shi ，响应 200。如图2
3、当在数据库中删除此自定义页面的数据后，响应 500。如图3
4、当在数据库中找不到此自定义页面的数据后，代码实现如下
return response()->view('errors.404', [], 404);
5、由于 视图文件 errors.404，其要「继承」的视图文件是：/resources/views/layouts/basic.blade.php，在报错行的变量前添加 错误控制运算符：@ 。其中的代码修改如下
$title = @$page['seo_title'] ?: @$page['title'];
6、不再报错，如图4
