Access post body without bodyparser - express

Question

I am trying to send a bas64 encoded image to my express server and parse it there to save it to disk. Id like to implement this with a simple http post request but couldn't get it to work. My first implementation utilized a websocket server and worked well:
Client:
const object = JSON.stringify({
action: "add_image",
data: dataUrl,
})
ws.send(object)
Server:
ws.on("message", (message) => {
const req = JSON.parse(message);
fs.writeFile(
"path/to/file.png",
data.split(";base64,").pop(),
{ encoding: "base64" },
(err) => err && console.log(err)
)
}
This is my trying to get the same result with an http request.
Client:
const object = JSON.stringify({
action: "add_image",
data: dataUrl,
})
fetch("http://localhost:3001/add_image", {
method: "POST",
headers: new Headers({
Origin: window.origin,
Accept: "image/png",
"Content-Type": "image/png",
}),
mode: "cors",
body: object,
})
Server:
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.post("/add_image", function (req, res) {
console.log(req.body);
});
Unfortunately, req.body always logs an empty object.
I am not quite sure what I am lacking. Any help would be greatly appreciated.

Answer 1

I found the answer in this article. I needed to combine all individual chunks of the request and then use the data once the process is complete.
app.post("/add_image", function (req, res) {
let body = '';
req.on('data', chunk => {
body += chunk.toString();
});
req.on('end', () => {
console.log(JSON.parse(body));
res.end('ok');
});
});