Upload & Download Files

Files can be uploaded and downloaded using FoalTS file system. It allows you to use different types of file storage such as the local file system or cloud storage.

Configuration

First install the package.

npm install @foal/storage

Then specify in your configuration the file storage to be used and its settings. In this example, we will use the local file system with the uploaded directory (you must create it at the root of your project).

{
  "settings": {
    "disk": {
      "driver": "local",
      "local": {
        "directory": "uploaded"
      }
    }
  }
}

File Uploads

This technique is available in Foal v1.7 onwards.

Files can be uploaded using multipart/form-data requests. The @ValidateMultipartFormDataBody hook parses the request body, validates the submitted fields and files and save them in streaming to your local or Cloud storage. It also provides the ability to create file buffers if you wish.

Using Buffers

import { Context, Post } from '@foal/core';
import { ValidateMultipartFormDataBody } from '@foal/storage';

export class UserController {

  @Post('/profile')
  @ValidateMultipartFormDataBody({
    files: {
      profile: { required: true },
      images: { required: false, multiple: true }
    }
  })
  uploadProfilePhoto(ctx: Context) {
    const buffer = ctx.request.body.files.profile;
    const buffers = ctx.request.body.files.images;
  }

}

The names of the file fields must be provided in the files parameter of the hook. Uploaded files which are not listed here are simply ignored.

The required parameter tells the hook if it should return a 400 - BAD REQUEST error if no file has been uploaded for the given field. In this case, the controller method is not executed.

When the upload is successful, the request body object is set with the buffer files.

Value of multiple	Files uploaded	Value in the request object
false (default)	None	null
	At least one	A buffer
true	None	An empty array
	At least one	An array of buffers

Using Local or Cloud Storage (streaming)

Instead of using buffers, you can also choose to save directly the file to your local or Cloud storage. To do this, you need to add the name of the target directory in your hook options. The value returned in the ctx is an object containing the relative path of the file.

With the previous configuration, this path is relative to the uploaded directory. Note that must create the uploaded/images and uploaded/images/profiles directories before you can upload a file.

import { Context, Post } from '@foal/core';
import { ValidateMultipartFormDataBody } from '@foal/storage';

export class UserController {

  @Post('/profile')
  @ValidateMultipartFormDataBody({
    files: {
      profile: { required: true, saveTo: 'images/profiles' }
    }
  })
  uploadProfilePhoto(ctx: Context) {
    const { path } = ctx.request.body.files.profile;
    // images/profiles/GxunLNJu3RXI9l7C7cQlBvXFQ+iqdxSRJmsR4TU+0Fo=.png
  }

}

Adding Fields

Multipart requests can also contain non-binary fields such as a string. These fields are validated and parsed by the hook.

import { Context, Post } from '@foal/core';
import { ValidateMultipartFormDataBody } from '@foal/storage';

export class UserController {

  @Post('/profile')
  @ValidateMultipartFormDataBody({
    fields: {
      description: { type: 'string' }
    },
    files: {
      profile: { required: true }
    }
  })
  uploadProfilePhoto(ctx: Context) {
    const { path } = ctx.request.body.files.profile;
    // images/profiles/GxunLNJu3RXI9l7C7cQlBvXFQ+iqdxSRJmsR4TU+0Fo=.png
    const { description } = ctx.request.body.fields;
  }

}

Specifying File Limits

Optional settings can be provided in the configuration to limit the size or number of files uploaded.

{
  "settings": {
    "multipartRequests": {
      "fileSizeLimit": 1024,
      "fileNumberLimit": 4,
    }
  }
}

Setting	Type	Description
fileSizeLimit	number	The maximum file size (in bytes).
fileNumberLimit	number	The maximum number of files (useful for multiple file fields).

File Downloads

This technique is available in Foal v1.6 onwards.

Files can be downloaded using the method createHttpResponse of the Disk service. The returned object is optimized for downloading a (large) file in streaming.

import { dependency, Get } from '@foal/core';
import { Disk } from '@foal/storage';

class ApiController {

  @dependency
  disk: Disk;

  @Get('/download')
  download() {
    return this.disk.createHttpResponse('avatars/foo.jpg');
  }

  @Get('/download2')
  download() {
    return this.disk.createHttpResponse('avatars/foo.jpg', {
      forceDownload: true,
      filename: 'avatar.jpg'
    });
  }

}

Option	Type	Description
forceDownload	boolean	It indicates whether the response should include the Content-Disposition: attachment header. If this is the case, browsers will not attempt to display the returned file (e.g. with the browser's PDF viewer) and will download the file directly.
filename	string	Default name proposed by the browser when saving the file. If it is not specified, FoalTS extracts the name from the path (foo.jpg in the example).

Usage with a Database

This example shows how to attach a profile picture to a user and how to retrieve and update it.

Create a new directory uploaded/images/profiles at the root of your project.

user.entity.ts

import {
  BaseEntity, Column, Entity, PrimaryGeneratedColumn
} from 'typeorm';

@Entity()
export class User extends BaseEntity {

  @PrimaryGeneratedColumn()
  id: number;

  @Column()
  profile: string;

}

app.controller.ts

import { Context, createHttpResponseFile, dependency, Get, HttpResponseNotFound, HttpResponseRedirect, HttpResponseOK, Post, render } from '@foal/core';
import { Disk, ValidateMultipartFormDataBody } from '@foal/storage';

import { User } from './entities';

// @JWTRequired OR @TokenRequired
// OR a custom hook that sets Context.user.
export class AppController {

  @dependency
  disk: Disk;

  @Post('/profile')
  @ValidateMultipartFormDataBody({
    files: {
      profile: { required: true, saveTo: 'images/profiles' }
    }
  })
  async uploadProfilePicture(ctx: Context<User>) {
    const user = ctx.user;
    if (user.profile) {
      await this.disk.delete(user.profile);
    }

    user.profile = ctx.request.body.files.profile.path;
    await user.save();

    return new HttpResponseRedirect('/');
  }

  @Get('/profile')
  async downloadProfilePicture(ctx: Context<User>) {
    const { profile } = ctx.user;

    if (!profile) {
      return new HttpResponseNotFound();
    }

    return this.disk.createHttpResponse(profile);
  }

  @Get('/')
  index() {
    return render('./templates/index.html');
  }

}

templates/index.html

<!DOCTYPE html>
<html>
<body>
  <img src="/profile">
  <form action="/profile" method="post" enctype="multipart/form-data">
      <input type="file" name="profile">
      <input type="submit" value="Upload image" name="submit">
  </form>
</body>
</html>

Static Files

Static files, such as HTML, CSS, images, and JavaScript, are served by default from the public directory.

Static directory

If necessary, this directory can be modified using the configuration key settings.staticPath.

{
  "settings": {
    "staticPath": "assets"
  }
}

Virtual prefix path

In case you need to add a virtual prefix path to your static files, you can do so with the staticPathPrefix configuration key.

{
  "settings": {
    "staticPathPrefix": "/static"
  }
}

Example

Static file	URL path with no prefix	URL path with the prefix /static
index.html	/ and /index.html	/static and /static/index.html
styles.css	/styles.css	/static/styles.css
app.js	/app.js	/static/app.js

Deprecated components

The createHttpResponseFile function

Deprecated since v1.6. Use the method createHttpResponseFile of the Disk service instead.

Warning: This package only allows you to download files from your local file system. It does not work with Cloud storage.

FoalTS provides the function createHttpResponseFile to download files in the browser from the server's local file system.

import { createHttpResponseFile, Get } from '@foal/core';

class AppController {

  @Get('/download')
  download() {
    return createHttpResponseFile({
      directory: 'uploaded/',
      file: 'my-pdf.pdf'
    });
  }

}

Option	Type	Description
directory	string	Path of the directory where the file is located (e.g. uploaded/).
file	string	Name of the file with its extension (e.g. report.pdf). If the string provided is a path (e.g. downloaded/report.pdf), then Foal will automatically extract the filename (i.e. report.pdf).
forceDownload (optional)	boolean	It indicates whether the response should include the Content-Disposition: attachment header. If this is the case, browsers will not attempt to display the returned file (e.g. with the browser's PDF viewer) and will download the file directly.
filename (optional)	string	Default name proposed by the browser when saving the file. If it is not specified, FoalTS extracts the name from the file option.

The @foal/formidable package

Deprecated since v1.7. Use the @ValidateMultipartFormDataBody hook instead.

Warning: This package only allows you to upload files to your local file system. It does not work with Cloud storage.

You can upload files to your local file system using the library formidable. It will automatically parse the incoming form and save the submitted file(s) in the directory of your choice. A random id is generated for each saved file.

npm install formidable @types/formidable
npm install @foal/formidable

The package @foal/formidable is a small package that allows you to use formidable with promises. It only has one function: parseForm.

Assuming that the client submits a form with a field named file1 containing a file, you can save this file using IncomingForm and parseForm.

import { Context, HttpResponseOK, Post } from '@foal/core';
import { parseForm } from '@foal/formidable';
import { IncomingForm } from 'formidable';

export class AppController {

  @Post('/upload')
  async upload(ctx: Context) {
    const form = new IncomingForm();
    form.uploadDir = 'uploaded';
    form.keepExtensions = true;
    const { fields, files } = await parseForm(form, ctx);

    console.log(files.file1);
    // {
    //   "size": 14911887,
    //   "path": "uploaded/upload_de9cb95c.pdf",
    //   "name": "example.pdf",
    //   "type": "application/pdf",
    //   "mtime": "2019-03-25T13:58:27.988Z"
    // }

    return new HttpResponseOK(
      'The file has correctly been uploaded. '
      + 'You can find it on the server at '
      + files.file1.path
    );
  }

}