read pdf in azure function using pdf2json

Question

I successfully implemented pdf2json to fetch and read pdf from url using node.

However, Azure function is an async function and finishes execution before pdfPipe.on("pdfParser_dataReady", pdf => {}) is executed.

My implementation is as follows

var request = require('request');
var PDFParser = require("pdf2json");

var pdfParser = new PDFParser(this, 1);
var pdfPipe = request({ url: pdfUrl, encoding: null }).pipe(pdfParser);
pdfPipe.on("pdfParser_dataError", err => console.error(err));
pdfPipe.on("pdfParser_dataReady", pdf => {
   /// hndle pdfData
});

This works well in node on my machine. But I need to convert pdfPipe.on('---', function(){}) to async and await as the azure function does not wait for pdfPipe to finish.

How to do that?

Answer 1

Solved Using following approach

async function streamToPdf(readableStream) {
    return new Promise((resolve, reject) => {
        readableStream.on("pdfParser_dataReady", (pdf) => {
            resolve(pdf);
        });
        readableStream.on("pdfParser_dataError", reject);
    });
}

and then

var pdfPipe = request({ url: pdfUrl, encoding: null }).pipe(pdfParser);

var pdf = await streamToPdf(pdfPipe);