File upload with React, Express and Google Cloud Storage with folder structure

#googlecloudstorage #express #react #fileupload

For the front end, we will use FilePond. It has a plugin for React for file uploads that supports previews, validations, drag and drop, etc.
NOTE: This tutorial assumes that you know how to setup React and Express.

Start by yarn/npm installing these:

react-filepond
filepond
filepond-plugin-image-preview
filepond-plugin-image-exif-orientation

import { FilePond, registerPlugin } from "react-filepond"
import "filepond/dist/filepond.min.css"
import FilePondPluginImageExifOrientation from "filepond-plugin-image-exif-orientation"
import FilePondPluginImagePreview from "filepond-plugin-image-preview"
import "filepond-plugin-image-preview/dist/filepond-plugin-image-preview.css"

Filepond component looks like this

<FilePond 
  files={imgCollection}
  allowMultiple={true}
  server={null}
  instantUpload={false}
  onupdatefiles={(fileItems) => onFileChange(fileItems)}>
</FilePond>

I use a form submit to trigger uploading of file/s.

Form:

<form onSubmit={onSubmit}>
    <div className="form-group">
        <button className="btn btn-primary" type="submit">Upload</button>
    </div>
    <div className="filepond-wrapper">
        <FilePond 
            files={imgCollection}
            allowMultiple={true}
            server={null}
            instantUpload={false}
            onupdatefiles={(fileItems) => onFileChange(fileItems)}>
        </FilePond>
    </div>
</form>

Functions and states:

    const [imgCollection, setImgCollection] = useState('')

    const onFileChange = (files) => {
        let items = files.map(fileItem => fileItem.file)
        setImgCollection([...imgCollection, items])
    }

    const onSubmit = (e) => {
        e.preventDefault()

        var formData = new FormData()

        for (let img in imgCollection[0]) {
            formData.append('imgCollection', imgCollection[0][img])
        }

        formData.append('folder', 'folder-name')

        axios.post(`${process.env.REACT_APP_API_ENDPOINT}/`, formData, {
        }).then(res => {
            console.log(res.data)
        })
    }

Install multer in your api folder.
In your Express API:

var express = require('express');
var router = express.Router();
var path = require('path')
var multer  = require('multer')
var upload = multer().array('imgCollection')

router.post('/', function(req, res, next) {
  // Imports the Google Cloud client library.
  const {Storage} = require('@google-cloud/storage');

  const storage = new Storage({projectId: 'gcp-project-id', keyFilename: path.join(__dirname, '../creds.json')});

  try {
    async function uploadFile(file, folder) {
      let bucketName = 'bucket-name'
      let bucket = storage.bucket(bucketName)

      let newFileName = folder + '/' + file.originalname;

      let fileUpload = bucket.file(newFileName);
      const blobStream = fileUpload.createWriteStream({
          metadata: {
              contentType: file.mimetype
          }
      });

      blobStream.on('error', (error) => {
          console.log('Something is wrong! Unable to upload at the moment.' + error);
      });

      blobStream.on('finish', () => {
          const url = `https://storage.googleapis.com/${bucket.name}/${fileUpload.name}`; //image url from firebase server
          console.log(url)

      });

      blobStream.end(file.buffer);
    }

    upload(req, res, function(err) {
      let files = req.files

      for (let file in files) {
        uploadFile(files[file], req.body.folder)
      }

      if(err) {
          return res.end("Error uploading file." + err);
      }
      res.end("File is uploaded");
    })
  } catch (err) {
    res.send(err)
  }
});

module.exports = router;

And that's it!

Hope you liked it.

Rock on,
FM

Top comments (13)

vijaj-soni-Noetic • Dec 30 '19

const [imgCollection, setImgCollection] = useState('')
const [client, setClient] = useState('')
const [section, setSection] = useState('Section')

const onFileChange = (files) => {
    let items = files.map(fileItem => fileItem.file)
    setImgCollection([...imgCollection, items])
}

where i use these line of code its given me error

Faith Morante • Dec 30 '19

Hello,

What error do you get? Note, I'm using React Hooks.

Robert Terrell • Mar 5 '20

I noticed when i submit a file using the form it uploads correctly but for some reason it turns red and states error during load. My console shows the following: filepond.js:3139 GET localhost:3000/%5Bobject%20Object%5D 404 (Not Found) is there something I need to do to prevent this?

Faith Morante • Mar 5 '20

I wont be able to see that link as it is served through your localhost. Can you provide a screenshot of the error? thanks

Robert Terrell • Mar 5 '20 • Edited

That's what the error displays as in the console. The error message is the following:

"filepond.js:3139 GET localhost:3000/%5Bobject%20Object%5D 404 (Not Found)"

the file input turns red and continually flickers saying error during load. What's strange tho is that the file uploads correctly and displays, so im wondering if its the file change code that's possibly creating the error.