Problem with form-data request with node.JS - form-data

Question

Good morning. I will try to explains my problems. So i must create the back-side of a web site, and i can't retrieve information of a form-data request. The request contains a object and an image but when i do console.log(req.body.key)i obtain an wonderful undefined.
Below the source code of the application. The front is created with Angular and the back with Node.JS
Back-end:
+app.js
const express = require("express") ,
app = express () ,
moongoose = require("mongoose") ,
bodyParser = require("body-parser") ,
path = require("path") ,
userRoute = require("./routage/user") ,
sauceRoute = require("./routage/sauces") ;
moongoose.connect("mongodb://localhost/Pekito" , {
useNewUrlParser: true ,
useUnifiedTopology: true
})
.then(() => {console.log("Connecte a mongo")})
.catch((error) => {console.log(error)}) ;
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use("/api/auth/" , userRoute) ;
app.use("/api/sauces/" , sauceRoute) ;
module.exports = app ;
+routes
exports.createSauces = (req , res , next) => {
console.log(req.body.sauce) ; => undefined
}
the front-end:
createSauce(sauce: Sauce, image: File) {
return new Promise((resolve, reject) => {
const formData = new FormData();
formData.append('sauce', JSON.stringify(sauce));
formData.append('image', image);
this.http.post('http://localhost:3000/api/sauces', formData).subscribe(
(response: { message: string }) => {
resolve(response);
},
(error) => {
reject(error);
}
);
});
}
So if you can explain me my error i will be very grateful to you
NB: excuse for my english, i'am a french student)

Answer 1

FormData objects send multipart requests.
Your have body parsers for URL encoded and JSON encoded requests.
You need to add a body parser capable of handling multipart.
See the documentation for the body-parser module:
This does not handle multipart bodies, due to their complex and typically large nature. For multipart bodies, you may be interested in the following modules:
busboy and connect-busboy
multiparty and connect-multiparty
formidable
multer
Pick one of those modules and follow its instructions.