Add custom fonts support for Unicode PDFs

packages/markdown-pdf/README.md

@@ -29,6 +29,35 @@ const outputStream = fs.createWriteStream(`./test.pdf`);
 pdfTransformer.toPdf(ciceroMarkJson, options, outputStream );
 ```
 
+### Unicode Font Support
+
+> Note: The default Liberation fonts support Latin characters only. For Unicode support (Cyrillic, Chinese, Arabic, etc.), provide custom fonts via the `fonts` parameter.
+
+ Example:
+``` javascript
+const { PdfTransformer, DefaultFonts } = require('@accordproject/markdown-pdf');
+
+// Extend default fonts with a Unicode-capable font
+const customFonts = {
+    ...DefaultFonts,
+    NotoSans: {
+        normal: '/path/to/NotoSans-Regular.ttf',
+        bold: '/path/to/NotoSans-Bold.ttf',
+        italics: '/path/to/NotoSans-Italic.ttf',
+        bolditalics: '/path/to/NotoSans-BoldItalic.ttf'
+    }
+};
+
+const pdfmakeDOM = await PdfTransformer.ciceroMarkToPdfMake(ciceroMarkJson);
+pdfmakeDOM.defaultStyle = { fontSize: 12, font: 'NotoSans', lineHeight: 1.5 };
+
+const pdfBuffer = await PdfTransformer.pdfMakeToPdfBuffer(
+    pdfmakeDOM, 
+    null,  // progress callback
+    customFonts  // your custom fonts
+);
+```
+
 ## License <a name="license"></a>
 Accord Project source code files are made available under the Apache License, Version 2.0 (Apache-2.0), located in the LICENSE file. Accord Project documentation files are made available under the Creative Commons Attribution 4.0 International License (CC-BY-4.0), available at http://creativecommons.org/licenses/by/4.0/.
 

packages/markdown-pdf/index.js

@@ -21,3 +21,4 @@
 
 module.exports.PdfTransformer = require('./lib/PdfTransformer');
 module.exports.ToPdfMake = require('./lib/ToPdfMake');
+module.exports.DefaultFonts = require('./lib/pdfmakeutil').defaultFonts;

packages/markdown-pdf/src/PdfTransformer.js

@@ -42,10 +42,11 @@ class PdfTransformer extends PdfTransformerBase {
      * Converts a pdfmake DOM to a PDF Buffer
      * @param {*} input - pdfmake DOM (JSON)
      * @param {*} progressCallback - a callback function used during pdf emit
+     * @param {object} [fonts] - optional custom fonts object for pdfmake (defaults to defaultFonts)
      * @return {*} a pdf buffer
      */
-    static async pdfMakeToPdfBuffer(input, progressCallback) {
-        return PdfTransformerBase.toBuffer(input, PdfTransformerBase.pdfMakeToPdfStreamWithCallback(progressCallback));
+    static async pdfMakeToPdfBuffer(input, progressCallback, fonts) {
+        return PdfTransformerBase.toBuffer(input, PdfTransformerBase.pdfMakeToPdfStreamWithCallback(progressCallback, fonts));
     }
 }
 

packages/markdown-pdf/src/PdfTransformerBase.js

@@ -99,9 +99,10 @@ class PdfTransformerBase {
     /**
      * Converts a pdfmake DOM to a PDF Buffer
      * @param {*} progressCallback - a callback function used during pdf emit
+     * @param {object} [fonts] - optional custom fonts object for pdfmake (defaults to defaultFonts)
      * @return {*} a function from input and stream, adding the pdf to the stream
      */
-    static pdfMakeToPdfStreamWithCallback(progressCallback) {
+    static pdfMakeToPdfStreamWithCallback(progressCallback, fonts) {
         return (input, outputStream) => {
 
             if (!input.defaultStyle) {
@@ -113,8 +114,9 @@ class PdfTransformerBase {
                 };
             }
 
-            // The Pdf printer
-            const printer = new PdfPrinter(defaultFonts);
+            // The Pdf printer - use custom fonts if provided, otherwise use defaultFonts
+            const fontsToUse = fonts || defaultFonts;
+            const printer = new PdfPrinter(fontsToUse);
 
             // Printing to stream
             const pdfDoc = printer.createPdfKitDocument(input, { progressCallback });
@@ -127,9 +129,10 @@ class PdfTransformerBase {
      * Converts a pdfmake DOM to a PDF Buffer
      * @param {*} input - pdfmake DOM (JSON)
      * @param {*} outputStream - the output stream
+     * @param {object} [fonts] - optional custom fonts object for pdfmake (defaults to defaultFonts)
      */
-    static async pdfMakeToPdfStream(input, outputStream) {
-        return PdfTransformerBase.pdfMakeToPdfStreamWithCallback()(input, outputStream);
+    static async pdfMakeToPdfStream(input, outputStream, fonts) {
+        return PdfTransformerBase.pdfMakeToPdfStreamWithCallback(null, fonts)(input, outputStream);
     }
 }