React Multiple File Upload example (with Typescript)

bezkoder React, Typescript

In this tutorial, I will show you way to build React Multiple File Upload example using Typescript, Hooks, Axios and Multipart File for making HTTP requests, Bootstrap for progress bar and display list of files’ information (with download url).

More Practice:
– Upload Image in React Typescript example (with Preview)
– React Typescript CRUD example
– React Hook Form Typescript example with Validation
– React Custom Hook in Typescript example
– React Query and Axios (Typescript) example
– Spring Boot + React Typescript example

Serverless with Firebase:
– React Typescript Firebase CRUD with Realtime Database
– React Typescript Firestore CRUD example with Cloud Firestore


React Typescript Multiple File upload Overview

We’re gonna create a React Multiple Files upload application using Typescript, Hooks, in that user can:

  • see the upload process (percentage) of each file with progress bars
  • view all uploaded files
  • download link to file when clicking on the file name

react-multiple-file-upload-typescript-example

When there is an error on uploading file:

react-multiple-file-upload-example-typescript

Technology

  • React 18/17/16
  • Axios 0.27.2
  • Bootstrap 4

Rest API for File Upload & Storage

Here are APIs that we will use Axios to make HTTP requests:

Methods Urls Actions
POST /upload upload a File
GET /files get List of Files (name & url)
GET /files/[filename] download a File

You can find how to implement the Rest APIs Server at one of following posts:
– Node Express File Upload Rest API example
– Node Express File Upload to MongoDB example
– Node Express File Upload to Google Cloud Storage example
– Spring Boot Multipart File upload (to static folder) example

Project Structure

After building the React Typescript project is done, the folder structure will look like this:

react-multiple-file-upload-typescript-project

Let me explain it briefly.

– FileUploadService provides functions to save File and get Files using Axios.
– FilesUpload contains multiple files upload form, progress bar, display of list files.
– File exports IFile interface.
– App.tsx is the container that we embed all React components.

– http-common.ts initializes Axios with HTTP base Url and headers.
– We configure port for our App in .env

Setup React Multiple File Upload Project

Open cmd at the folder you want to save Project folder, run command:
npx create-react-app react-typescript-multiple-file-upload --template typescript
Or: yarn create react-app react-typescript-multiple-file-upload --template typescript

After the process is done. We create additional folders and files like the following tree:

public
src
components
FilesUpload.tsx
services
FileUploadService.ts
types
File.ts
App.css
App.tsx
index.tsx
package.json

Import Bootstrap to React Multiple File Upload App

Run command: npm install [email protected].
Or: yarn add [email protected]

Open src/App.tsx and modify the code inside it as following-

import "bootstrap/dist/css/bootstrap.min.css";
import "./App.css";

const App: React.FC = () => {
  return (
    ...
  );
}

export default App;

Initialize Axios for React Typescript Client

Let’s install axios with command: npm install [email protected].
Or: yarn add [email protected]

Under src folder, we create http-common.ts file with following code:

import axios from "axios";

export default axios.create({
  baseURL: "http://localhost:8080",
  headers: {
    "Content-type": "application/json",
  },
});

You can change the baseURL that depends on REST APIs url that your Server configures.

Create Service for File Upload

This service will use Axios to send HTTP requests.
There are 2 functions:

  • upload(file): POST form data with a callback for tracking upload progress
  • getFiles(): GET list of Files’ information

services/FileUploadService.ts

import http from "../http-common";

const upload = (file: File, onUploadProgress: any): Promise<any> => {
  let formData = new FormData();

  formData.append("file", file);

  return http.post("/upload", formData, {
    headers: {
      "Content-Type": "multipart/form-data",
    },
    onUploadProgress,
  });
};

const getFiles = () : Promise<any> => {
  return http.get("/files");
};

const FileUploadService = {
  upload,
  getFiles,
};

export default FileUploadService;

– First we import Axios as http from http-common.ts.

– Inside upload() method, we use FormData to store key-value pairs. It helps to build an object which corresponds to HTML form using append() method.

– We pass onUploadProgress to exposes progress events. This progress event are expensive (change detection for each event), so you should only use when you want to monitor it.

– We call Axios post() to send an HTTP POST for uploading a File to Rest APIs Server and get() method for HTTP GET request to retrieve all stored files.

Create File Interface

We will export a IFile type with 2 properties: url and name.

types/File.ts

export default interface IFile {
  url: string,
  name: string,
}

Create Page for Upload Multiple Files

Let’s create a Multiple File Upload UI with Progress Bar, Card, Button and Message.

First we create a React template with React Hooks (useState, useEffect) and import FileUploadService:

components/FilesUpload.tsx

import { useState, useEffect, useRef } from "react";
import UploadService from "../services/FileUploadService";

const FilesUpload: React.FC = () => {
  
  return (
    
  );
};

export default FilesUpload;

Then we define the state using React Hooks:

...
import IFile from "../types/File";

const FilesUpload: React.FC = () => {

  const [selectedFiles, setSelectedFiles] = useState<FileList | null>(null);
  const [progressInfos, setProgressInfos] = useState<Array<ProgressInfo>>([]);
  const [message, setMessage] = useState<Array<string>>([]);
  const [fileInfos, setFileInfos] = useState<Array<IFile>>([]);
  const progressInfosRef = useRef<any>(null);

  ...
}

Next we define selectFiles() function which helps us to get the selected Files from <input type="file" > element later.

const FilesUpload: React.FC = () => {
  ...
  const selectFiles = (event: React.ChangeEvent<HTMLInputElement>) => {
    setSelectedFiles(event.target.files);
    setProgressInfos([]);
    setMessage([]);
  };
  ...
}

We use selectedFiles array for accessing current selected Files. Every file has a corresponding progress Info (percentage, file name) and index in progressInfos array.

const FilesUpload: React.FC = () => {
  ...
  const uploadFiles = () => {
    if (selectedFiles != null) {
      const files = Array.from(selectedFiles);

      let _progressInfos = files.map((file) => ({
        percentage: 0,
        fileName: file.name
      }));

      progressInfosRef.current = _progressInfos;

      const uploadPromises = files.map((file, i) => upload(i, file));

      Promise.all(uploadPromises)
        .then(() => UploadService.getFiles())
        .then((files) => {
          setFileInfos(files.data);
        });

      setMessage([]);
    }
  };
  ...
}

In the code above, for each file, we invoke upload() function which call UploadService.upload() method with an index (i) parameter and return a Promise.

After all the processes are done, we call UploadService.getFiles() to get the files’ information and assign the result to fileInfos state, which is an array of {name, url} objects.

So create following upload() function like this:

const FilesUpload: React.FC = () => {
  ...

  const upload = (idx: number, file: File) => {
    let _progressInfos = [...progressInfosRef.current];
    return UploadService.upload(file, (event) => {
      _progressInfos[idx].percentage = Math.round(
        (100 * event.loaded) / event.total
      );
      setProgressInfos(_progressInfos);
    })
      .then(() => {
        setMessage((prevMessage) => [
          ...prevMessage,
          file.name + ": Successful!"
        ]);
      })
      .catch((err: any) => {
        _progressInfos[idx].percentage = 0;
        setProgressInfos(_progressInfos);

        let msg = file.name + ": Failed!";
        if (err.response && err.response.data && err.response.data.message) {
          msg += " " + err.response.data.message;
        }

        setMessage((prevMessage) => [
          ...prevMessage,
          msg
        ]);
      });
  };
  ...
}

The progress will be calculated basing on event.loaded and event.total and percentage value is assigned to specific item of progressInfos by the index.

We also need to do this work in the Effect Hook useEffect() method which serves the same purpose as componentDidMount():

const FilesUpload: React.FC = () => {
  ...
  useEffect(() => {
    UploadService.getFiles().then((response) => {
      setFileInfos(response.data);
    });
  }, []);

  ...
}

Now we return the Upload File UI. Add the following code inside return() block:

const FilesUpload: React.FC = () => {
  ...

  return (
    <div>
      {progressInfos &&
        progressInfos.length > 0 &&
        progressInfos.map((progressInfo: ProgressInfo, index: number) => (
          <div className="mb-2" key={index}>
            <span>{progressInfo.fileName}</span>
            <div className="progress">
              <div
                className="progress-bar progress-bar-info"
                role="progressbar"
                aria-valuenow={progressInfo.percentage}
                aria-valuemin={0}
                aria-valuemax={100}
                style={{ width: progressInfo.percentage + "%" }}
              >
                {progressInfo.percentage}%
              </div>
            </div>
          </div>
        ))}

      <div className="row my-3">
        <div className="col-8">
          <label className="btn btn-default p-0">
            <input type="file" multiple onChange={selectFiles} />
          </label>
        </div>

        <div className="col-4">
          <button
            className="btn btn-success btn-sm"
            disabled={!selectedFiles}
            onClick={uploadFiles}
          >
            Upload
          </button>
        </div>
      </div>

      {message.length > 0 && (
        <div className="alert alert-secondary" role="alert">
          <ul>
            {message.map((item, i) => {
              return <li key={i}>{item}</li>;
            })}
          </ul>
        </div>
      )}

      <div className="card">
        <div className="card-header">List of Files</div>
        <ul className="list-group list-group-flush">
          {fileInfos &&
            fileInfos.map((file, index) => (
              <li className="list-group-item" key={index}>
                <a href={file.url}>{file.name}</a>
              </li>
            ))}
        </ul>
      </div>
    </div>
  );
};

In the code above, we use Bootstrap Progress Bar:

  • .progress as a wrapper
  • inner .progress-bar to indicate the progress
  • .progress-bar requires style to set the width by percentage
  • .progress-bar also requires role and some aria attributes to make it accessible
  • label of the progress bar is the text within it

To display List of uploaded files, we iterate over fileInfos array using map() function. On each file item, we use file.url as href attribute and file.name for showing text.

Don’t forget to export the function component:

const FilesUpload: React.FC = () => {
  ...
}

export default FilesUpload;

You can simplify import statement with:
Absolute Import in React

Add Multiple Files Upload Component to App Component

Open App.tsx, import and embed the FilesUpload Component tag.

import "bootstrap/dist/css/bootstrap.min.css";
import "./App.css";

import FilesUpload from "./components/FilesUpload";

const App: React.FC = () => {
  return (
    <div className="container" style={{ width: "600px" }}>
      <div className="my-3">
        <h3>bezkoder.com</h3>
        <h4>React Typescript Multiple Files Upload</h4>
      </div>

      <FilesUpload />
    </div>
  );
}

export default App;

Configure Port for React Multiple File Upload App

Because most of HTTP Server use CORS configuration that accepts resource sharing restricted to some sites or ports, and if you use the Project in this post for making Server, you need to configure port for our App.

In project folder, create .env file with following content:

PORT=8081

So our app will run at port 8081.

Run the App

You can find how to implement the Rest APIs Server at one of following posts:
– Node Express File Upload Rest API example
– Node Express File Upload to MongoDB example
– Node Express File Upload to Google Cloud Storage example
– Spring Boot Multipart File upload (to static folder) example

Run this React Multiple File Upload App with command: npm start.
Or: yarn start

Open Browser with url http://localhost:8081/ and check the result.

Conclusion

Today we’re learned how to build a React Typescript application for upload Multiple Files using Hooks, Axios, Bootstrap with Progress Bar. We also provide the ability to show list of files, upload progress percentage, and to download file from the server.

Happy Learning! See you again.

Further Reading

– React Typescript Multiple Image Upload example (with Preview)
– React Typescript CRUD example
– React Hook Form Typescript example with Validation
– React Custom Hook in Typescript example
– React Query and Axios (Typescript) example
– Spring Boot + React Typescript example

Serverless with Firebase:
– React Typescript Firebase CRUD with Realtime Database
– React Typescript Firestore CRUD example with Cloud Firestore

Fullstack:
– React + Spring Boot + MySQL: CRUD example
– React + Spring Boot + PostgreSQL: CRUD example
– React + Spring Boot + MongoDB: CRUD example
– React + Node + Express + MySQL: CRUD example
– React + Node + Express + PostgreSQL example
React Redux + Node + Express + MySQL: CRUD example
– React + Node + Express + MongoDB exampleReact + Django + Rest Framework example

Source Code

You can find the complete source code for this tutorial at Github.