Added automatic img to base64 conversion

ref #5

package.json

@@ -39,6 +39,8 @@
   "license": "CC-BY-NC-SA-4.0",
   "dependencies": {
     "@odit/class-validator-jsonschema": "^2.1.1",
+    "axios": "^0.21.1",
+    "cheerio": "^1.0.0-rc.5",
     "class-transformer": "0.3.1",
     "class-validator": "^0.13.1",
     "consola": "^2.15.0",
@@ -48,6 +50,7 @@
     "handlebars": "^4.7.6",
     "i18next": "^19.8.7",
     "i18next-fs-backend": "^1.0.8",
+    "mime-types": "^2.1.28",
     "puppeteer": "^7.0.1",
     "reflect-metadata": "^0.1.13",
     "routing-controllers": "^0.9.0-alpha.6",
@@ -77,4 +80,4 @@
       "publish": false
     }
   }
-}
+}

src/PdfCreator.ts

@@ -1,11 +1,13 @@
+import axios from 'axios';
+import cheerio from "cheerio";
 import fs from "fs";
 import Handlebars from 'handlebars';
 import i18next from "i18next";
 import Backend from 'i18next-fs-backend';
+import mime from "mime-types";
 import path from 'path';
 import puppeteer from "puppeteer";
 import { Runner } from './models/Runner';
-
 /**
  * This class is responsible for all things pdf creation.
  * This uses the html templates from src/templates.
@@ -58,12 +60,47 @@ export class PdfCreator {
         return await this.renderPdf(result, { format: "A5", landscape: true });
     }
 
+    /**
+     * Converts all images in html to base64.
+     * Works with image files in the template directory or images from urls.
+     * @param html The html string whoms images shall get replaced.
+     */
+    public async imgToBase64(html): Promise<string> {
+        const $ = cheerio.load(html)
+        $('img').each(async (index, element) => {
+            let imgsrc = $(element).attr("src");
+            const img_type = mime.lookup(imgsrc);
+
+            if (!(img_type.includes("image"))) {
+                throw new Error("File is not image mime type");
+            }
+
+            let image;
+            if (imgsrc.startsWith("http")) {
+                image = (await axios.get(imgsrc)).data;
+                image = Buffer.from(image).toString('base64');
+            }
+            else {
+                if (imgsrc.startsWith("./")) {
+                    imgsrc = imgsrc.replace("./", "");
+                }
+                image = fs.readFileSync(`${this.templateDir}/${imgsrc}`, { encoding: "base64" });
+            }
+
+            image = `data:${img_type};base64,${image}`
+            $(element).attr("src", image)
+        })
+
+        return $.html();
+    }
+
     /**
      * This method manages the creation of pdfs via puppeteer.
      * @param html The HTML that should get rendered.
      * @param options Puppeteer PDF option (eg: {format: "A4"})
      */
     public async renderPdf(html: string, options): Promise<any> {
+        html = await this.imgToBase64(html);
         let page = await this.browser.newPage();
         await page.setContent(html);
         const pdf = await page.pdf(options);