Angular 17 + Node.js Express: File Upload example

In this tutorial, I will show you way to build Angular 17 with Node.js Express: File/Image upload & download example.

More Practice:
Angular 17 + Node Express + MySQL example
Angular 17 + Node Express + PostgreSQL example
Angular 17 + Node Express + MongoDB example
Angular 17 + Node Express: JWT Authentication & Authorization example
Server side Pagination with Node and Angular


Overview

We’re gonna create a full-stack Angular 17 + Node Express: File/Image upload with Express Rest APIs, in that user can:

  • know the file upload status
  • view all uploaded files
  • download by clicking on the file name

angular-17-node-express-file-upload-example

All uploaded files will be saved in uploads folder:

angular-17-node-express-file-upload-folder-example

With the backend in this tutorial, you can also apply one of following frontend:
Angular 17 File upload example with Progress bar
Angular 17 Image Upload with Preview example
Angular 17 Multiple Files upload example
Angular Material 17 File upload example

Technology

Server:

  • express 4.18.2
  • multer 1.4.4-lts.1
  • cors 2.8.5

Client:

  • Angular 17
  • RxJS 7
  • Bootstrap 4

Node.js Express Rest API for File Upload & Storage

Node.js Server will provide APIs:

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

This is the project structure:

angular-17-node-express-file-upload-example-server-project

resources/static/assets/uploads: folder for storing uploaded files.
middleware/upload.js: initializes Multer Storage engine and defines middleware function to save uploaded files in uploads folder.
file.controller.js exports Rest APIs: POST a file, GET all files’ information, download a File with url.
routes/index.js: defines routes for endpoints that is called from HTTP Client, use controller to handle requests.
server.js: initializes routes, runs Express app.

You can find Step by Step to implement the Node.js Express Server (with Github) at:
Node.js Express File Upload Rest API example using Multer

With MongoDB database:
Node.js Express File Upload to MongoDB example

Or working with GCS:
Node.js Express File Upload to Google Cloud Storage example

Setup Angular 17 File Upload Project

Let’s open cmd and use Angular CLI to create a new Angular 17 Project as following command:

ng new angular-17-file-upload
? Which stylesheet format would you like to use? CSS
? Do you want to enable Server-Side Rendering (SSR) and Static Site Generation (SSG/Prerendering)? No

We also need to generate some Components and Services:

ng g s services/file-upload
ng g c components/file-upload

Now you can see that our project directory structure looks like this.

Angular 17 Client Project Structure

angular-17-node-express-file-upload-example-client-project

Let me explain it briefly.

– We import necessary library, components in app.module.ts.
file-upload.service provides methods to save File and get Files from Rest API Server using HttpClient.
file-upload.component contains upload form, progress bar, display of list files.
app.component is the container that we embed all components.
index.html or style.css for importing the Bootstrap.

Set up HttpClient

Open app.config.ts and import provideHttpClient from Angular Http Module:

import { ApplicationConfig } from '@angular/core';
import { provideRouter } from '@angular/router';
import { provideHttpClient } from '@angular/common/http';

import { routes } from './app.routes';

export const appConfig: ApplicationConfig = {
  providers: [
    provideRouter(routes),
    provideHttpClient()
  ]
};

Add Bootstrap to the project

Run the command: npm install [email protected].

Next, open angular.json and add following code:

"styles": [
  "node_modules/bootstrap/dist/css/bootstrap.min.css",
  "src/styles.css"
],
"scripts": [
  "node_modules/jquery/dist/jquery.slim.min.js",
  "node_modules/popper.js/dist/umd/popper.min.js",
  "node_modules/bootstrap/dist/js/bootstrap.min.js"
]

Create Angular 17 Service for Upload Files

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

  • upload(file): returns Observable<HttpEvent<any>> that we’re gonna use in File Upload Component
  • getFiles(): returns a list of Files’ information as Observable object

services/file-upload.service.ts

import { Injectable } from '@angular/core';
import { HttpClient, HttpRequest, HttpEvent } from '@angular/common/http';
import { Observable } from 'rxjs';

@Injectable({
  providedIn: 'root',
})
export class FileUploadService {
  private baseUrl = 'http://localhost:8080';

  constructor(private http: HttpClient) {}

  upload(file: File): Observable<HttpEvent<any>> {
    const formData: FormData = new FormData();
    formData.append('file', file);

    const req = new HttpRequest('POST', `${this.baseUrl}/upload`, formData, {
      responseType: 'json',
    });

    return this.http.request(req);
  }

  getFiles(): Observable<any> {
    return this.http.get(`${this.baseUrl}/files`);
  }
}

FormData is a data structure that can be used to store key-value pairs. We use it to build an object which corresponds to an HTML form with append() method.
– We call the request(PostRequest) & get() method of HttpClient to send an HTTP POST & Get request to the File Upload Rest API server.

Create Component for File Upload UI

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

First we need to use the following imports:

file-upload.component.ts

import { Component, OnInit } from '@angular/core';
import { CommonModule } from '@angular/common';
import { HttpResponse } from '@angular/common/http';
import { Observable } from 'rxjs';
import { FileUploadService } from '../../services/file-upload.service';

@Component({
  selector: 'app-file-upload',
  standalone: true,
  imports: [CommonModule],
  templateUrl: './file-upload.component.html',
  styleUrl: './file-upload.component.css',
})
export class FileUploadComponent implements OnInit { ... }

Then we define the some variables and inject FileUploadService as follows:

export class FileUploadComponent implements OnInit {
  currentFile?: File;
  message = '';
  fileInfos?: Observable<any>;

  constructor(private uploadService: FileUploadService) { }

}

Next we define selectFile() method. It helps us to get the selected File.

selectFile(event: any): void {
  this.currentFile = event.target.files.item(0);
}

Next we write upload() method for upload file:

export class FileUploadComponent implements OnInit {
  currentFile?: File;
  message = '';
  fileInfos?: Observable<any>;

  constructor(private uploadService: FileUploadService) { }

  selectFile(event: any): void {
    this.currentFile = event.target.files.item(0);
  }

  upload(): void {
    if (this.currentFile) {
      this.uploadService.upload(this.currentFile).subscribe({
        next: (event: any) => {
          if (event instanceof HttpResponse) {
            this.message = event.body.message;
            this.fileInfos = this.uploadService.getFiles();
          }
        },
        error: (err: any) => {
          console.log(err);

          if (err.error && err.error.message) {
            this.message = err.error.message;
          } else {
            this.message = 'Could not upload the file!';
          }
        },
        complete: () => {
          this.currentFile = undefined;
        },
      });
    }
  }
}

We use currentFile for accessing current File as the first Item. Then we call uploadService.upload() method on the currentFile.

If the transmission is done, the event will be a HttpResponse object. At this time, we call uploadService.getFiles() to get the files’ information and assign the result to fileInfos variable.

We also need to do this work in ngOnInit() method:

ngOnInit(): void {
  this.fileInfos = this.uploadService.getFiles();
}

Now we create the HTML template of the Upload File UI. Add the following content to file-upload.component.html file:

<div class="row">
  <div class="col-8">
    <label class="btn btn-default p-0">
      <input type="file" (change)="selectFile($event)" />
    </label>
  </div>

  <div class="col-4">
    <button class="btn btn-success btn-sm" [disabled]="!currentFile" (click)="upload()">
      Upload
    </button>
  </div>
</div>

@if (message) {
<div class="alert alert-secondary" role="alert">{{ message }}</div>
}

<div class="card mt-3">
  <div class="card-header">List of Files</div>
  <ul class="list-group list-group-flush">
    @for (file of fileInfos | async; track file.name) {
    <li class="list-group-item">
      <a href="{{ file.url }}">{{ file.name }}</a>
    </li>
    }
  </ul>
</div>

Add Upload File Component to App Component

Import FileUploadComponent in app.component.ts

import { Component } from '@angular/core';
import { CommonModule } from '@angular/common';
import { RouterOutlet } from '@angular/router';
import { FileUploadComponent } from './components/file-upload/file-upload.component';

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [CommonModule, RouterOutlet, FileUploadComponent],
  templateUrl: './app.component.html',
  styleUrl: './app.component.css'
})
export class AppComponent {
  title = 'Angular 17 File Upload example';
}

Open app.component.html and embed the FileUpload Component with <app-file-upload> tag.

<div class="container" style="width:500px">
  <div class="my-3">
    <h3>bezkoder.com</h3>
    <h4>{{ title }}</h4>
  </div>

  <app-file-upload></app-file-upload>
</div>

Run the App

– Server side: First we need to create uploads folder with the path resources/static/assets. Then run Node.js Server with command: node server.js.

– Client side: Because we configure CORS for origin: http://localhost:8081, so you need to run this Angular 15 Client with command:
ng serve --port 8081

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

Further Reading

Fullstack:
Angular 17 + Node Express + MySQL example
Angular 17 + Node Express + PostgreSQL example
Angular 17 + Node Express + MongoDB example
Angular 17 + Node Express: JWT Authentication & Authorization example
Server side Pagination with Node and Angular

Conclusion

Today we’re learned how to build File Upload and Download example using Angular 17 and Node.js Express. We also provide the ability to show list of files, upload progress using Bootstrap, and to download file from the server.

You can find Step by Step to implement the Node.js Server at:
Node.js Express File Upload Rest API example using Multer

With MongoDB Database:
Node.js Express File Upload to MongoDB example

Or upload file to GCS:
Node.js Express File Upload to Google Cloud Storage example

If you want to upload multiple files at once, you can find the instruction here:
Angular 17 Multiple Files upload example with Progress Bar

You will want to know how to run both projects in one place:
How to Integrate Angular with Node.js Restful Services

Source Code

Node Express Server
Angular 17 Client.
Angular 17 Client with Progress bar