使用Laravel导出大量数据的PDF

Question

我有下面的代码

$html = '';
foreach ($posts as $post) {
        $html .= '<div class="table-scrollable">
                        <table id="posts" class="table table-bordered table-hover">
                            <thead>
                                <tr>
                                    <th>Id</th>
                                    <th>Name</th>
                                    <th>Title</th>
                                </tr>
                            </thead>
                            <tbody id="body"><tr>
                                <td>'
                . $post->id . ' 
                                </td>
                                <td>' .
                $post->name .
                '</td>
                                <td>'
                . $post->title .
                '</td> 
                    </tr>
                   </tbody>
                </table>
            </div>';
}
return PDF::load($html, 'A4', 'portrait')->download('my_pdf');

当我想下载大量数据时，出现了以下错误：The localhost page isn’t working localhost is currently unable to handle this request. 但是，如果我尝试下载例如20个条目，则可以正常工作。我该怎么办？ laravel.log

[2016-11-24 13:15:17] production.ERROR: 错误异常 'ErrorException'，错误信息为 'Undefined variable: data_start'，位于文件 '/Applications/XAMPP/xamppfiles/htdocs/dicom/app/controllers/IncasariController.php' 的第58行。堆栈跟踪：0 /Applications/XAMPP/xamppfiles/htdocs/dicom/app/controllers/IncasariController.php(58)：Illuminate\Exception\Handler->handleError(8, 'Undefined varia...', '/Applications/X...', 58, Array)；1 [内部函数]：IncasariController->filtrareChitante()；2 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Routing/Controller.php(231)：call_user_func_array(Array, Array)；3 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Routing/ControllerDispatcher.php(93)：Illuminate\Routing\Controller->callAction('filtrareChitant...', Array)；4 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Routing/ControllerDispatcher.php(62)：Illuminate\Routing\ControllerDispatcher->call(Object(IncasariController), Object(Illuminate\Routing\Route), 'filtrareChitant...')；5 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Routing/Router.php(962)：Illuminate\Routing\ControllerDispatcher->dispatch(Object(Illuminate\Routing\Route), Object(Illuminate\Http\Request), 'IncasariControl...', 'filtrareChitant...')；6 [内部函数]：Illuminate\Routing\Router->Illuminate\Routing{closure}()；7 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Routing/Route.php(109)：call_user_func_array(Object(Closure), Array)；8 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Routing/Router.php(1028)：Illuminate\Routing\Route->run(Object(Illuminate\Http\Request))；9 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Routing/Router.php(996)：Illuminate\Routing\Router->dispatchToRoute(Object(Illuminate\Http\Request))；10 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Foundation/Application.php(775)：Illuminate\Routing\Router->dispatch(Object(Illuminate\Http\Request))；11 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Foundation/Application.php(745)：Illuminate\Foundation\Application->dispatch(Object(Illuminate\Http\Request))；12 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Session/Middleware.php(72)：Illuminate\Foundation\Application->handle(Object(Illuminate\Http\Request), 1, true)；13 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Cookie/Queue.php(47)：Illuminate\Session\Middleware->handle(Object(Illuminate\Http\Request), 1, true)；14 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Cookie/Guard.php(51)：Illuminate\Cookie\Queue->handle(Object(Illuminate\Http\Request), 1, true)；15 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/stack/builder/src/Stack/StackedHttpKernel.php(23)：Illuminate\Cookie\Guard->handle(Object(Illuminate\Http\Request), 1, true)；16 /Applications/XAMPP/xamppfiles/htdocs/dicom/vendor/laravel/framework/src/Illuminate/Foundation/Application.php(641)：Stack\StackedHttpKernel->handle(Object(Illuminate\Http\Request))；17 /Applications/XAMPP/xamppfiles/htdocs/dicom/public/index.php(49)：Illuminate\Foundation\Application->run()；18 {main} [] []

并且在网页上是：

The localhost page isn’t working

localhost is currently unable to handle this request.

- Sulde1985

---

请告诉我们更多关于您正在使用的软件的信息（xampp？Mac？Linux？），以及您目前用于PDF的软件包。 - Imam Assidiqqi

请发布一些日志条目，例如在laravel.log中或在apache/nginx error.log中。 - sleepless

@ImamAssidiqqi 我正在使用XAMPP。这是我使用的软件包：https://github.com/barryvdh/laravel-dompdf/tree/0.4 - Sulde1985

那个错误提示了其他地方的问题 - 运行 composer install，composer dump-autoload。 - Jonny C

@JonC 运行了...但是什么也没有发生 :( - Sulde1985

Answer 1

您的代码假定每个记录都有一个ID、名称和标题。在调用它们之前，我建议检查是否已经设置了这些内容。可以像这样进行检查。

foreach ($posts as $post) {

$id= isset($post->id) ? $post->id : 'ID Not Set';
$name= isset($post->name) ? $post->name : 'Name Not Set';
$title= isset($post->title) ? $post->title : ' Title Not Set';

    $html .= '<div class="table-scrollable">
                    <table id="posts" class="table table-bordered table-hover">
                        <thead>
                            <tr>
                                <th>Id</th>
                                <th>Name</th>
                                <th>Title</th>
                            </tr>
                        </thead>
                        <tbody id="body">
                          <tr>
                            <td>'. $id .'</td>
                            <td>'. $name .'</td>
                            <td>'. $title .'</td> 
                          </tr>
               </tbody>
            </table>
        </div>';
}

如果它们没有被设置，可能会导致您的代码出现“对象未找到”错误。 您可以从storage/logs文件夹检查日志。

- Jonny C

---

注意：自PHP 7.0以来，可以添加$id ?? '';。这将检查$id是否设置，如果是，则设置变量。如果变量未设置，则采用给定的变量，在本例中为一个空字符串。 - D. J.

Answer 2

嗯，你试图将大型数据集导出为PDF。我的建议：

1. 尝试制作自定义CSS以减少页面加载（您可以将类复制粘贴到自定义CSS中）
2. 在XAMPP上更改php.ini的最大执行时间（1分钟、5分钟、10分钟等）

- Localhousee