PDF: Started building system to allow custom DOMPDF font loading

app/Config/exports.php

@@ -68,7 +68,7 @@
          * Times-Roman, Times-Bold, Times-BoldItalic, Times-Italic,
          * Symbol, ZapfDingbats.
          */
-        'font_dir' => storage_path('fonts/'),  // advised by dompdf (https://github.com/dompdf/dompdf/pull/782)
+        'font_dir' => storage_path('fonts/dompdf'),  // advised by dompdf (https://github.com/dompdf/dompdf/pull/782)
 
         /**
          * The location of the DOMPDF font cache directory.
@@ -78,7 +78,7 @@
          *
          * Note: This directory must exist and be writable by the webserver process.
          */
-        'font_cache' => storage_path('fonts/'),
+        'font_cache' => storage_path('fonts/dompdf/cache'),
 
         /**
          * The location of a temporary directory.

app/Exports/PdfGenerator.php

@@ -4,6 +4,8 @@
 
 use BookStack\Exceptions\PdfExportException;
 use Dompdf\Dompdf;
+use FontLib\Font;
+use Illuminate\Support\Str;
 use Knp\Snappy\Pdf as SnappyPdf;
 use Symfony\Component\Process\Exception\ProcessTimedOutException;
 use Symfony\Component\Process\Process;
@@ -60,12 +62,65 @@ protected function renderUsingDomPdf(string $html): string
         $domPdf = new Dompdf($options);
         $domPdf->setBasePath(base_path('public'));
 
+        $fontMetrics = $domPdf->getFontMetrics();
+        $userFontfamilies = $this->getUserDomPdfFontFamilies();
+        foreach ($userFontfamilies as $fontFamily => $fonts) {
+            try {
+                $fontMetrics->setFontFamily($fontFamily, $fonts);
+            } catch (\Exception $exception) {
+                $expectedPath = storage_path('fonts/dompdf');
+                throw new PdfExportException("Failed to create required font data in {$expectedPath}, Ensure all content in this location is writable by the web server");
+            }
+        }
+
         $domPdf->loadHTML($this->convertEntities($html));
         $domPdf->render();
 
         return (string) $domPdf->output();
     }
 
+    /**
+     * @return array<string, array<string, string>>
+     */
+    protected function getUserDomPdfFontFamilies(): array
+    {
+        $fontStore = storage_path('fonts/dompdf');
+        if (!is_dir($fontStore)) {
+            return [];
+        }
+
+        $fontFamilies = [];
+        $fontFiles = glob($fontStore . DIRECTORY_SEPARATOR . '*.ttf');
+        foreach ($fontFiles as $fontFile) {
+            $fontFileName = basename($fontFile, '.ttf');
+            $expectedUfm = $fontStore . DIRECTORY_SEPARATOR . $fontFileName . '.ufm';
+            if (!file_exists($expectedUfm)) {
+                $font = Font::load($fontFile);
+                $font->parse();
+                try {
+                    $font->saveAdobeFontMetrics($expectedUfm);
+                } catch (\Exception $exception) {
+                    throw new PdfExportException("Failed to create required font data at $expectedUfm, Ensure this location is writable by the web server");
+                }
+            }
+
+            $nameParts = explode('-', $fontFileName);
+            if (count($nameParts) === 1 || $nameParts[1] === 'Regular') {
+                $nameParts[1] = 'Normal';
+            }
+
+            $family = trim(strtolower(preg_replace('/([A-Z])/', ' $1', $nameParts[0])));
+            $variation = Str::snake($nameParts[1]);
+            if (!isset($fontFamilies[$family])) {
+                $fontFamilies[$family] = [];
+            }
+
+            $fontFamilies[$family][$variation] = $fontStore . DIRECTORY_SEPARATOR . $fontFileName;
+        }
+
+        return $fontFamilies;
+    }
+
     /**
      * @throws PdfExportException
      */

storage/fonts/.gitignore

@@ -1,2 +1,6 @@
+# Font cache files have once been stored directly in this folder
+# therefore its important the contents non-ignored by git
+# are chosen selectively
 *
-!.gitignore
+!.gitignore
+!dompdf/

storage/fonts/dompdf/.gitignore

@@ -0,0 +1,3 @@
+*
+!.gitignore
+!cache/

storage/fonts/dompdf/cache/.gitignore

@@ -0,0 +1,2 @@
+*
+!.gitignore

tests/Exports/PdfExportTest.php

@@ -79,6 +79,39 @@ public function test_page_pdf_export_opens_details_blocks()
         $this->assertStringContainsString('<details open="open"', $pdfHtml);
     }
 
+    public function test_custom_fonts_loaded_for_dom_pdf_when_used()
+    {
+        // Set up custom font usage
+        $page = $this->entities->page()->forceFill([
+            'html'     => '<p><strong>Bold</strong>text</p>',
+        ]);
+        $page->save();
+        $this->setSettings([
+            'app-custom-head' => '<style>* { font-family: "meow words"}</style>'
+        ]);
+        $normalFont = $this->files->testFilePath('fonts/Cardiff.ttf');
+        $normalFontTarget = storage_path('fonts/dompdf/MeowWords.ttf');
+        $boldFont = $this->files->testFilePath('fonts/Cardiff-Bold.ttf');
+        $boldFontTarget = storage_path('fonts/dompdf/MeowWords-Bold.ttf');
+        copy($normalFont, $normalFontTarget);
+        copy($boldFont, $boldFontTarget);
+
+        $resp = $this->asEditor()->get($page->getUrl('/export/pdf'));
+        $resp->assertStatus(200);
+
+        // Existance of UFM files indicates the metrics have been generated
+        $this->assertFileExists(storage_path('fonts/dompdf/MeowWords.ufm'));
+        $this->assertFileExists(storage_path('fonts/dompdf/MeowWords-Bold.ufm'));
+        // Existence of cache json files indicates the fonts have been used
+        $this->assertFileExists(storage_path('fonts/dompdf/cache/MeowWords.ufm.json'));
+        $this->assertFileExists(storage_path('fonts/dompdf/cache/MeowWords-Bold.ufm.json'));
+
+        $filesToCleanUp = [...glob(storage_path('fonts/dompdf/Meow*')), ...glob(storage_path('fonts/dompdf/cache/Meow*'))];
+        foreach ($filesToCleanUp as $file) {
+            unlink($file);
+        }
+    }
+
     public function test_wkhtmltopdf_only_used_when_allow_untrusted_is_true()
     {
         $page = $this->entities->page();

tests/test-data/fonts/attribution.txt

@@ -0,0 +1,2 @@
+Font files by Roger White, in public domain.
+https://web.archive.org/web/20110609213636/http://www.rogersfonts.org.uk/