BookStack Code Mirror - bookstack/blob - app/Entities/Tools/PdfGenerator.php

   1 <?php
   2
   3 namespace BookStack\Entities\Tools;
   4
   5 use BookStack\Exceptions\PdfExportException;
   6 use Knp\Snappy\Pdf as SnappyPdf;
   7 use Dompdf\Dompdf;
   8 use Symfony\Component\Process\Process;
   9
  10 class PdfGenerator
  11 {
  12     const ENGINE_DOMPDF = 'dompdf';
  13     const ENGINE_WKHTML = 'wkhtml';
  14     const ENGINE_COMMAND = 'command';
  15
  16     /**
  17      * Generate PDF content from the given HTML content.
  18      * @throws PdfExportException
  19      */
  20     public function fromHtml(string $html): string
  21     {
  22         return match ($this->getActiveEngine()) {
  23             self::ENGINE_COMMAND => $this->renderUsingCommand($html),
  24             self::ENGINE_WKHTML => $this->renderUsingWkhtml($html),
  25             default => $this->renderUsingDomPdf($html)
  26         };
  27     }
  28
  29     /**
  30      * Get the currently active PDF engine.
  31      * Returns the value of an `ENGINE_` const on this class.
  32      */
  33     public function getActiveEngine(): string
  34     {
  35         if (config('exports.pdf_command')) {
  36             return self::ENGINE_COMMAND;
  37         }
  38
  39         if ($this->getWkhtmlBinaryPath() && config('app.allow_untrusted_server_fetching') === true) {
  40             return self::ENGINE_WKHTML;
  41         }
  42
  43         return self::ENGINE_DOMPDF;
  44     }
  45
  46     protected function getWkhtmlBinaryPath(): string
  47     {
  48         $wkhtmlBinaryPath = config('exports.snappy.pdf_binary');
  49         if (file_exists(base_path('wkhtmltopdf'))) {
  50             $wkhtmlBinaryPath = base_path('wkhtmltopdf');
  51         }
  52
  53         return $wkhtmlBinaryPath ?: '';
  54     }
  55
  56     protected function renderUsingDomPdf(string $html): string
  57     {
  58         $options = config('exports.dompdf');
  59         $domPdf = new Dompdf($options);
  60         $domPdf->setBasePath(base_path('public'));
  61
  62         $domPdf->loadHTML($this->convertEntities($html));
  63         $domPdf->render();
  64
  65         return (string) $domPdf->output();
  66     }
  67
  68     /**
  69      * @throws PdfExportException
  70      */
  71     protected function renderUsingCommand(string $html): string
  72     {
  73         $command = config('exports.pdf_command');
  74         $inputHtml = tempnam(sys_get_temp_dir(), 'bs-pdfgen-html-');
  75         $outputPdf = tempnam(sys_get_temp_dir(), 'bs-pdfgen-output-');
  76
  77         $replacementsByPlaceholder = [
  78             '{input_html_path}' => $inputHtml,
  79             '{output_pdf_path}' => $outputPdf,
  80         ];
  81
  82         foreach ($replacementsByPlaceholder as $placeholder => $replacement) {
  83             $command = str_replace($placeholder, escapeshellarg($replacement), $command);
  84         }
  85
  86         file_put_contents($inputHtml, $html);
  87
  88         $process = Process::fromShellCommandline($command);
  89         $process->setTimeout(15);
  90         $process->run();
  91
  92         if (!$process->isSuccessful()) {
  93             throw new PdfExportException("PDF Export via command failed with exit code {$process->getExitCode()}, stdout: {$process->getOutput()}, stderr: {$process->getErrorOutput()}");
  94         }
  95
  96         $pdfContents = file_get_contents($outputPdf);
  97         unlink($outputPdf);
  98
  99         if ($pdfContents === false) {
 100             throw new PdfExportException("PDF Export via command failed, unable to read PDF output file");
 101         } else if (empty($pdfContents)) {
 102             throw new PdfExportException("PDF Export via command failed, PDF output file is empty");
 103         }
 104
 105         return $pdfContents;
 106     }
 107
 108     protected function renderUsingWkhtml(string $html): string
 109     {
 110         $snappy = new SnappyPdf($this->getWkhtmlBinaryPath());
 111         $options = config('exports.snappy.options');
 112         return $snappy->getOutputFromHtml($html, $options);
 113     }
 114
 115     /**
 116      * Taken from https://github.com/barryvdh/laravel-dompdf/blob/v2.1.1/src/PDF.php
 117      * Copyright (c) 2021 barryvdh, MIT License
 118      * https://github.com/barryvdh/laravel-dompdf/blob/v2.1.1/LICENSE
 119      */
 120     protected function convertEntities(string $subject): string
 121     {
 122         $entities = [
 123             '€' => '&euro;',
 124             '£' => '&pound;',
 125         ];
 126
 127         foreach ($entities as $search => $replace) {
 128             $subject = str_replace($search, $replace, $subject);
 129         }
 130         return $subject;
 131     }
 132 }