BookStack Code Mirror - bookstack/blob - app/Exports/PdfGenerator.php

   1 <?php
   2
   3 namespace BookStack\Exports;
   4
   5 use BookStack\Exceptions\PdfExportException;
   6 use Dompdf\Dompdf;
   7 use Knp\Snappy\Pdf as SnappyPdf;
   8 use Symfony\Component\Process\Exception\ProcessTimedOutException;
   9 use Symfony\Component\Process\Process;
  10
  11 class PdfGenerator
  12 {
  13     const ENGINE_DOMPDF = 'dompdf';
  14     const ENGINE_WKHTML = 'wkhtml';
  15     const ENGINE_COMMAND = 'command';
  16
  17     /**
  18      * Generate PDF content from the given HTML content.
  19      * @throws PdfExportException
  20      */
  21     public function fromHtml(string $html): string
  22     {
  23         return match ($this->getActiveEngine()) {
  24             self::ENGINE_COMMAND => $this->renderUsingCommand($html),
  25             self::ENGINE_WKHTML => $this->renderUsingWkhtml($html),
  26             default => $this->renderUsingDomPdf($html)
  27         };
  28     }
  29
  30     /**
  31      * Get the currently active PDF engine.
  32      * Returns the value of an `ENGINE_` const on this class.
  33      */
  34     public function getActiveEngine(): string
  35     {
  36         if (config('exports.pdf_command')) {
  37             return self::ENGINE_COMMAND;
  38         }
  39
  40         if ($this->getWkhtmlBinaryPath() && config('app.allow_untrusted_server_fetching') === true) {
  41             return self::ENGINE_WKHTML;
  42         }
  43
  44         return self::ENGINE_DOMPDF;
  45     }
  46
  47     protected function getWkhtmlBinaryPath(): string
  48     {
  49         $wkhtmlBinaryPath = config('exports.snappy.pdf_binary');
  50         if (file_exists(base_path('wkhtmltopdf'))) {
  51             $wkhtmlBinaryPath = base_path('wkhtmltopdf');
  52         }
  53
  54         return $wkhtmlBinaryPath ?: '';
  55     }
  56
  57     protected function renderUsingDomPdf(string $html): string
  58     {
  59         $options = config('exports.dompdf');
  60         $domPdf = new Dompdf($options);
  61         $domPdf->setBasePath(base_path('public'));
  62
  63         $domPdf->loadHTML($this->convertEntities($html));
  64         $domPdf->render();
  65
  66         return (string) $domPdf->output();
  67     }
  68
  69     /**
  70      * @throws PdfExportException
  71      */
  72     protected function renderUsingCommand(string $html): string
  73     {
  74         $command = config('exports.pdf_command');
  75         $inputHtml = tempnam(sys_get_temp_dir(), 'bs-pdfgen-html-');
  76         $outputPdf = tempnam(sys_get_temp_dir(), 'bs-pdfgen-output-');
  77
  78         $replacementsByPlaceholder = [
  79             '{input_html_path}' => $inputHtml,
  80             '{output_pdf_path}' => $outputPdf,
  81         ];
  82
  83         foreach ($replacementsByPlaceholder as $placeholder => $replacement) {
  84             $command = str_replace($placeholder, escapeshellarg($replacement), $command);
  85         }
  86
  87         file_put_contents($inputHtml, $html);
  88
  89         $timeout = intval(config('exports.pdf_command_timeout'));
  90         $process = Process::fromShellCommandline($command);
  91         $process->setTimeout($timeout);
  92
  93         try {
  94             $process->run();
  95         } catch (ProcessTimedOutException $e) {
  96             throw new PdfExportException("PDF Export via command failed due to timeout at {$timeout} second(s)");
  97         }
  98
  99         if (!$process->isSuccessful()) {
 100             throw new PdfExportException("PDF Export via command failed with exit code {$process->getExitCode()}, stdout: {$process->getOutput()}, stderr: {$process->getErrorOutput()}");
 101         }
 102
 103         $pdfContents = file_get_contents($outputPdf);
 104         unlink($outputPdf);
 105
 106         if ($pdfContents === false) {
 107             throw new PdfExportException("PDF Export via command failed, unable to read PDF output file");
 108         } else if (empty($pdfContents)) {
 109             throw new PdfExportException("PDF Export via command failed, PDF output file is empty");
 110         }
 111
 112         return $pdfContents;
 113     }
 114
 115     protected function renderUsingWkhtml(string $html): string
 116     {
 117         $snappy = new SnappyPdf($this->getWkhtmlBinaryPath());
 118         $options = config('exports.snappy.options');
 119         return $snappy->getOutputFromHtml($html, $options);
 120     }
 121
 122     /**
 123      * Taken from https://github.com/barryvdh/laravel-dompdf/blob/v2.1.1/src/PDF.php
 124      * Copyright (c) 2021 barryvdh, MIT License
 125      * https://github.com/barryvdh/laravel-dompdf/blob/v2.1.1/LICENSE
 126      */
 127     protected function convertEntities(string $subject): string
 128     {
 129         $entities = [
 130             '€' => '&euro;',
 131             '£' => '&pound;',
 132         ];
 133
 134         foreach ($entities as $search => $replace) {
 135             $subject = str_replace($search, $replace, $subject);
 136         }
 137         return $subject;
 138     }
 139 }