index.js

import express, { json } from "express";
import { writeFileSync, unlinkSync } from "fs";
import cors from "cors";
import carbone from "carbone";
import { convert } from "libreoffice-convert";
import { promisify } from "util";
import { v4 as uuidv4 } from "uuid";
import path from "path";

const _dirname = path.resolve();
const convertAsync = promisify(convert);

console.log(process.platform, process.arch);

const app = express();
const corsOptions = {
  origin: "*",
  optionsSuccessStatus: 200,
};
app.use(cors(corsOptions));
app.use(json({ limit: "200mb" }));

app.get("/", (req, res) => {
  res.send("Hello Carbone: Your IP: " + req.ip);
});

app.post("/generate", async (req, res) => {
  let { template, data, convertTo, templateExtension } = req.body;

  if (!convertTo) {
    convertTo = "pdf";
  }

  // convert base64 to binary
  const binary = Buffer.from(template, "base64");

  // template name with timestamp
  const input = path.join(
    _dirname,
    "output",
    `template-${uuidv4()}.${templateExtension}`
  );

  // write to disk
  writeFileSync(input, binary);

  const processResult = async (err, result) => {
    if (err) {
      return res
        .status(400)
        .json({ error: err.message, message: "Could parse data" });
    }

    try {
      // Convert it to pdf format with undefined filter (see Libre office docs about filter)
      const pdfBuf = await convertAsync(result, `${convertTo}`, undefined);

      // send to client
      res.contentType(`application/${convertTo}`);
      res.send(pdfBuf);
    } catch (error) {
      console.log(error);
      return res
        .status(500)
        .json({ error: error.message, message: "Could not convert to pdf" });
    }

    // delete template
    unlinkSync(input);
  };

  carbone.render(input, data, processResult);
});

const PORT = process.env.PORT || 8080;
app.listen(PORT, () => console.log(`Server started on port ${PORT}`));