Upload cropped image with Antd in React to Express multer

Question

I'm trying to upload a cropped image with Antd upload in React and receive it with multer in express. I'm appending image to formData then posting it with axios. But the multer field is empty. I didn't face any problem in simple file upload. But can't manage with Antd upload.

Here is my React code: API is set up axios. It is working everywhere.

export default class Upload extends Component {

    constructor(props) {
        super(props)
        this.state = {
            avatar: [],
            loading: true
        }
        this.onChange = this.onChange.bind(this)
    }

onChange(e) {
    let formData = new FormData()
    formData.append('avatar', e.file)
    API.post('/account/avatar', formData, config)
        .then(res => {
            console.log(res.data)
        })
    console.log(e.file)
}

   render() {
        return (
                        <ImgCrop shape='round'>
                            <Upload
                                action={this.onChange}
                                multiple={false}
                                showUploadList='false'
                                onChange={this.onChange}
                            >
                                <Button className='upload-avatar-btn'><i className='lnir lnir-pencil'></i></Button>
                            </Upload>
                        </ImgCrop>
       )
}

Logging e.file in browser's console is giving this:

{lastModifiedDate: 1595920324076, name: "anders-jilden-tcEGBIHm_6E-unsplash.jpg", uid: "rc-upload-1595919951039-2", lastModified: undefined, size: 70585, …}
lastModified: undefined
lastModifiedDate: 1595920324076
name: "anders-jilden-tcEGBIHm_6E-unsplash.jpg"
originFileObj: Blob {lastModifiedDate: 1595920324076, name: "anders-jilden-tcEGBIHm_6E-unsplash.jpg", uid: "rc-upload-1595919951039-2", size: 70585, type: "image/jpeg"}
percent: 100
size: 70585
status: "uploading"
type: "image/jpeg"
uid: "rc-upload-1595919951039-2"
__proto__: Object

Express code:

.post('/avatar', upload.fields([{ name: 'avatar', maxCount: 1 }]), (req, res) => {
    const files = req.files.avatar;
    console.log(req.files);
    console.log(req.files.avatar)
    res.send('Uploaded');
})

I'm getting 200 status code in client. But multer is not uploading anything. I have no idea what to do. console.log(req.files) is giving this:

[Object: null prototype] {}

Answer 1

First try to wait until upload finished via e.file.status === 'done'.

After this you can upload the original file object using e.file.originFileObj.

E.g.:

onChange(e) {
    if (info.file.status === 'done') {
        let formData = new FormData()
        formData.append('avatar', e.file.originFileObj)
        API.post('/account/avatar', formData, config)
           .then(res => {
               console.log(res.data)
           })
       console.log(e.file)
   }
}

This CodeSandBox is good tutorial for using Antd's Upload.

For further inspection of your issue you need to post a minimal reproducable example e.g. as Stackblitz.