PDF Exports: New command option and library/option cleanup

.env.example.complete

@@ -325,6 +325,14 @@ FILE_UPLOAD_SIZE_LIMIT=50
 # Can be 'a4' or 'letter'.
 EXPORT_PAGE_SIZE=a4
 
+# Export PDF Command
+# Set a command which can be used to convert a HTML file into a PDF file.
+# When false this will not be used.
+# String values represent the command to be called for conversion.
+# Supports '{input_html_path}' and '{output_pdf_path}' placeholder values.
+# Example: EXPORT_PDF_COMMAND="/scripts/convert.sh {input_html_path} {output_pdf_path}"
+EXPORT_PDF_COMMAND=false
+
 # Set path to wkhtmltopdf binary for PDF generation.
 # Can be 'false' or a path path like: '/home/bins/wkhtmltopdf'
 # When false, BookStack will attempt to find a wkhtmltopdf in the application

app/Config/app.php

@@ -116,8 +116,6 @@
     // Application Service Providers
     'providers' => ServiceProvider::defaultProviders()->merge([
         // Third party service providers
-        Barryvdh\DomPDF\ServiceProvider::class,
-        Barryvdh\Snappy\ServiceProvider::class,
         SocialiteProviders\Manager\ServiceProvider::class,
 
         // BookStack custom service providers

app/Config/dompdf.php → app/Config/exports.php

@@ -1,23 +1,45 @@
 <?php
 
 /**
- * DOMPDF configuration options.
+ * Export configuration options.
  *
  * Changes to these config files are not supported by BookStack and may break upon updates.
  * Configuration should be altered via the `.env` file or environment variables.
  * Do not edit this file unless you're happy to maintain any changes yourself.
  */
 
+$snappyPaperSizeMap = [
+    'a4'     => 'A4',
+    'letter' => 'Letter',
+];
+
 $dompdfPaperSizeMap = [
     'a4'     => 'a4',
     'letter' => 'letter',
 ];
 
+$exportPageSize = env('EXPORT_PAGE_SIZE', 'a4');
+
 return [
 
-    'show_warnings' => false,   // Throw an Exception on warnings from dompdf
+    // Set a command which can be used to convert a HTML file into a PDF file.
+    // When false this will not be used.
+    // String values represent the command to be called for conversion.
+    // Supports '{input_html_path}' and '{output_pdf_path}' placeholder values.
+    // Example: EXPORT_PDF_COMMAND="/scripts/convert.sh {input_html_path} {output_pdf_path}"
+    'pdf_command' => env('EXPORT_PDF_COMMAND', false),
 
-    'options'       => [
+    // 2024-04: Snappy/WKHTMLtoPDF now considered deprecated in regard to BookStack support.
+    'snappy' => [
+        'pdf_binary' => env('WKHTMLTOPDF', false),
+        'options' => [
+            'print-media-type' => true,
+            'outline'   => true,
+            'page-size' => $snappyPaperSizeMap[$exportPageSize] ?? 'A4',
+        ],
+    ],
+
+    'dompdf' => [
         /**
          * The location of the DOMPDF font directory.
          *
@@ -101,7 +123,7 @@
         /**
          * Whether to enable font subsetting or not.
          */
-        'enable_fontsubsetting' => false,
+        'enable_font_subsetting' => false,
 
         /**
          * The PDF rendering backend to use.
@@ -165,7 +187,7 @@
          *
          * @see CPDF_Adapter::PAPER_SIZES for valid sizes ('letter', 'legal', 'A4', etc.)
          */
-        'default_paper_size' => $dompdfPaperSizeMap[env('EXPORT_PAGE_SIZE', 'a4')] ?? 'a4',
+        'default_paper_size' => $dompdfPaperSizeMap[$exportPageSize] ?? 'a4',
 
         /**
          * The default paper orientation.
@@ -268,15 +290,6 @@
          */
         'font_height_ratio' => 1.1,
 
-        /**
-         * Enable CSS float.
-         *
-         * Allows people to disabled CSS float support
-         *
-         * @var bool
-         */
-        'enable_css_float' => true,
-
         /**
          * Use the HTML5 Lib parser.
          *
@@ -286,5 +299,4 @@
          */
         'enable_html5_parser' => true,
     ],
-
 ];

app/Entities/Tools/PdfGenerator.php

@@ -2,27 +2,28 @@
 
 namespace BookStack\Entities\Tools;
 
-use Barryvdh\DomPDF\Facade\Pdf as DomPDF;
-use Barryvdh\Snappy\Facades\SnappyPdf;
+use BookStack\Exceptions\PdfExportException;
+use Knp\Snappy\Pdf as SnappyPdf;
+use Dompdf\Dompdf;
+use Symfony\Component\Process\Process;
 
 class PdfGenerator
 {
     const ENGINE_DOMPDF = 'dompdf';
     const ENGINE_WKHTML = 'wkhtml';
+    const ENGINE_COMMAND = 'command';
 
     /**
      * Generate PDF content from the given HTML content.
+     * @throws PdfExportException
      */
     public function fromHtml(string $html): string
     {
-        if ($this->getActiveEngine() === self::ENGINE_WKHTML) {
-            $pdf = SnappyPDF::loadHTML($html);
-            $pdf->setOption('print-media-type', true);
-        } else {
-            $pdf = DomPDF::loadHTML($html);
-        }
-
-        return $pdf->output();
+        return match ($this->getActiveEngine()) {
+            self::ENGINE_COMMAND => $this->renderUsingCommand($html),
+            self::ENGINE_WKHTML => $this->renderUsingWkhtml($html),
+            default => $this->renderUsingDomPdf($html)
+        };
     }
 
     /**
@@ -31,8 +32,101 @@ public function fromHtml(string $html): string
      */
     public function getActiveEngine(): string
     {
-        $useWKHTML = config('snappy.pdf.binary') !== false && config('app.allow_untrusted_server_fetching') === true;
+        if (config('exports.pdf_command')) {
+            return self::ENGINE_COMMAND;
+        }
+
+        if ($this->getWkhtmlBinaryPath() && config('app.allow_untrusted_server_fetching') === true) {
+            return self::ENGINE_WKHTML;
+        }
+
+        return self::ENGINE_DOMPDF;
+    }
+
+    protected function getWkhtmlBinaryPath(): string
+    {
+        $wkhtmlBinaryPath = config('exports.snappy.pdf_binary');
+        if (file_exists(base_path('wkhtmltopdf'))) {
+            $wkhtmlBinaryPath = base_path('wkhtmltopdf');
+        }
+
+        return $wkhtmlBinaryPath ?: '';
+    }
+
+    protected function renderUsingDomPdf(string $html): string
+    {
+        $options = config('exports.dompdf');
+        $domPdf = new Dompdf($options);
+        $domPdf->setBasePath(base_path('public'));
+
+        $domPdf->loadHTML($this->convertEntities($html));
+        $domPdf->render();
+
+        return (string) $domPdf->output();
+    }
+
+    /**
+     * @throws PdfExportException
+     */
+    protected function renderUsingCommand(string $html): string
+    {
+        $command = config('exports.pdf_command');
+        $inputHtml = tempnam(sys_get_temp_dir(), 'bs-pdfgen-html-');
+        $outputPdf = tempnam(sys_get_temp_dir(), 'bs-pdfgen-output-');
 
-        return $useWKHTML ? self::ENGINE_WKHTML : self::ENGINE_DOMPDF;
+        $replacementsByPlaceholder = [
+            '{input_html_path}' => $inputHtml,
+            '{output_pdf_path}' => $outputPdf,
+        ];
+
+        foreach ($replacementsByPlaceholder as $placeholder => $replacement) {
+            $command = str_replace($placeholder, escapeshellarg($replacement), $command);
+        }
+
+        file_put_contents($inputHtml, $html);
+
+        $process = Process::fromShellCommandline($command);
+        $process->setTimeout(15);
+        $process->run();
+
+        if (!$process->isSuccessful()) {
+            throw new PdfExportException("PDF Export via command failed with exit code {$process->getExitCode()}, stdout: {$process->getOutput()}, stderr: {$process->getErrorOutput()}");
+        }
+
+        $pdfContents = file_get_contents($outputPdf);
+        unlink($outputPdf);
+
+        if ($pdfContents === false) {
+            throw new PdfExportException("PDF Export via command failed, unable to read PDF output file");
+        } else if (empty($pdfContents)) {
+            throw new PdfExportException("PDF Export via command failed, PDF output file is empty");
+        }
+
+        return $pdfContents;
+    }
+
+    protected function renderUsingWkhtml(string $html): string
+    {
+        $snappy = new SnappyPdf($this->getWkhtmlBinaryPath());
+        $options = config('exports.snappy.options');
+        return $snappy->getOutputFromHtml($html, $options);
+    }
+
+    /**
+     * Taken from https://github.com/barryvdh/laravel-dompdf/blob/v2.1.1/src/PDF.php
+     * Copyright (c) 2021 barryvdh, MIT License
+     * https://github.com/barryvdh/laravel-dompdf/blob/v2.1.1/LICENSE
+     */
+    protected function convertEntities(string $subject): string
+    {
+        $entities = [
+            '€' => '€',
+            '£' => '£',
+        ];
+
+        foreach ($entities as $search => $replace) {
+            $subject = str_replace($search, $replace, $subject);
+        }
+        return $subject;
     }
 }

app/Exceptions/PdfExportException.php

@@ -0,0 +1,7 @@
+<?php
+
+namespace BookStack\Exceptions;
+
+class PdfExportException extends \Exception
+{
+}

composer.json

@@ -17,11 +17,11 @@
         "ext-mbstring": "*",
         "ext-xml": "*",
         "bacon/bacon-qr-code": "^2.0",
-        "barryvdh/laravel-dompdf": "^2.0",
-        "barryvdh/laravel-snappy": "^1.0",
         "doctrine/dbal": "^3.5",
+        "dompdf/dompdf": "^2.0",
         "guzzlehttp/guzzle": "^7.4",
         "intervention/image": "^3.5",
+        "knplabs/knp-snappy": "^1.5",
         "laravel/framework": "^10.10",
         "laravel/socialite": "^5.10",
         "laravel/tinker": "^2.8",