error Path must be a string without null bytes [duplicate] - node.js

Question

I am using Angular 5 on front-end, Node on back-end and Mongo as the database. Now I am trying to save an image to the database but constantly getting this error. I can't figure out if I'm making mistake on front or back because this is my first time working with files. I did my research but it points mostly to angular 1.x.
HTML Component
<form [formGroup]="form" (ngSubmit)="onSubmitPhoto()">
<div class="form-group">
<input type="file" class="form-control" formControlName="photo">
</div>
<button class="btn btn-default" type="submit">Sačuvaj</button>
</form>
TS Component
onSubmitPhoto() {
this.profile.photo = this.form.value.photo;
this.usersService.updatePhoto(this.profile, this.id)
.subscribe(
data => {
this.router.navigateByUrl('/');
},
error => console.error(error)
);
}
Service
updatePhoto(profile: Profile, id: string) {
const body = new FormData();
body.append('photo', profile.photo);
const headers = new Headers({ 'Content-Type': 'application/json' });
return this.http.post('http://localhost:3000/profile/photo/' + id, body, { headers: headers })
.map((response: Response) => response.json())
.catch((error: Response) => {
return Observable.throw(error.json());
});
}
Node.JS
router.post('/photo/:id', (req, res) => {
console.log(req.files);
User.find({ _id: req.params.id })
.exec((err, user) => {
if (err) {
return res.status(500).json({
title: 'An error occured',
error: err
});
}
user.img.data = fs.readFileSync(req.files);
user.img.contentType = 'image/png';
user.save((err, obj) => {
if (err) {
throw err
}
console.log('success')
})
});
});
Model
const schema = new Schema({
img: { data: Buffer, contentType: String}
});
module.exports = mongoose.model('User', schema);
Any help is appreciated.
Also, loging req.files returns undefined.

Answer 1

To upload a file you need to wrapp it in a FormData instance as follows:
interface Profile {
photo: File;
}
updatePhoto(profile: Profile, id: string) {
const body = new FormData();
body.append('photo',profile.photo);
return this.http.post(`http://localhost:3000/profile/photo/${id}`, body,)
.map((response: Response) => response.json())
.catch((error: Response) => {
return Observable.throw(error.json());
});
}
Furthermore, your backend is most likely failing in the following section:
user.img.data = fs.readFileSync(req.body.photo);
Considering that you are now uploading a form with multipart/form-data encoding, you will need to use some middleware to parse the request in your backend as stated in the expressjs doc
You could use multer or express-fileupload
If you go with the second, you will need the following:
const fileUpload = require('express-fileupload');
router.use(fileUpload());// use express-fileupload as default parser for multipart/form-data encoding
router.post('/photo/:id', (req, res) => {
User.find({ _id: req.params.id })
.exec((err, user) => {
if (err) {
return res.status(500).json({
title: 'An error occured',
error: err
});
}
user.img.data = req.files.photo.data;
user.img.contentType = 'image/png';
user.save((err, obj) => {
if (err) {
throw err
}
console.log('success')
})
});
});