@gigster/module-loopback-file-upload

loopback-file-upload

Role	Name	Email	Slack
Product Owner	Frances Haugen	[e-mail]	[@frances]
Maintainer	Jerome Curlier	[e-mail]	[@jerome]
Contributor	Samuel Gordalina	[e-mail]	[@sam]

Overview

This module provides file upload for Loopback.

The module is using the Loopback Storage component. Please therefore review this component documentation to learn about this module.

The LoopBack storage component makes it easy to upload and download files to cloud storage providers and the local (server) file system.

• Amazon
• Azure
• Google Cloud
• Openstack
• Rackspace
• Local filesytem

Usage

  - name: loopback-file-upload
    location: 'npm:@gigster/module-loopback-file-upload@1.2.1'
    spec:
      minSize: 0
      maxSize: 20971520
      storage: filesystem
      containerName: uploads

Specification

Name	Status
containerName	the name of the folder or bucket to store the files into.
minSize	Minimum size of the file in bytes.
maxSize	Maximum size of the file in bytes.
storage	Which storage to use for the component, currently filesystem and amazonS3 are supported.

Uploadable model definition

A model is uploadable when it has the file-upload.uploadable tag.

By default, the uploadable model should have the following attributes.

Name	Status
filename	the uniquely generated filename.
displayName	the original file name.
url	the URL location to download the file.
size	the size of the file in bytes.
mimeType	the mime type for the file.
created	the date/time the file was uploaded.

Note: if you would like to change the list of attributes, you will need to update the uploader mixin generated code. The method storeFile is returning the upload object to be stored for the uploaded file.

This is an example of a uploadable model.

name: upload
public: false
properties:
  - name: filename
    type: string
  - name: displayName
    type: string
  - name: url
    type: string
  - name: size
    type: number
  - name: mimeType
    type: string
  - name: created
    type: date
relations:
  - name: profilePhoto
    type: hasOne
    model: user
    foreignKey: profilePhotoId
  - name: userPhotos
    type: hasMany
    model: user
    through: userPhoto
    foreignKey: photoId
  - name: productDocument
    type: hasMany
    model: product
    through: productDocument
    foreignKey: documentId
tags:
  - file-upload.uploadable

Endpoints

The module create a POST endpoint for each relation to an uploadable model.

Endpoint	Method	Description
POST /model/relation/upload ( for example /user/profilePhoto/upload)	relationUpload	Uploads a file

The following information is returned for each uplodaded file.

{
	"filename": "ae99c364-0218-4a33-a5e3-3fdb6e07e817.json",
	"displayName": "workspace.json",
	"size": 148841,
	"lastModified": "2017-11-22T20:15:15.376Z",
	"url": "http://0.0.0.0:3000/storage/uploadsBucket/ae99c364-0218-4a33-a5e3-3fdb6e07e817.json",
	"id": 47
}

We can then display the file using the URL provided.

Sample CURL commands

curl --request POST \
  --url http://localhost:3000/api/users/1/profilePhoto/upload \
  --header 'content-type: multipart/form-data; boundary=---011000010111000001101001' \
  --form file=

Environment variables

Name	Description
GIG_MAX_UPLOAD_SIZE	Maximum size of the file (checked by the storage component)
AWS_REGION	AWS region key when using AWS
AWS_KEY	AWS key when using AWS
AWS_SECRET_KEY	AWS secret key when using AWS

Dependencies

The loopback-file-upload depends on the loopback-models module. The loopback-models module should be defined before loopback-file-upload in the gig.yaml.

The following npm packages are used:

npm	version
loopback-component-storage	^3.3.1

Generation

Mixin

The Uploader mixin is added to the project. The mixin attaches an upload method to each relation defined in the mixin configuration, handles the file upload to the storage and store the file information in the uploadable model.

Models

For each relation to a uploadable model, the module contributes the upload endpoint. The endpoint is attached to the model through a mixins configuration in the model json file.

For example:

  "Uploader": {
    "relations": [
      "profilePhoto",
      "photos"
    ]
  }

The module also disable methods related to the uploadble methods.

For a many relationship, the following methods are disabled:

• prototype.__create__relation_name
• prototype.__update__relation_name
• prototype.__updateById__relation_name
• prototype.__link__relation_name
• prototype.__unlink__relation_name

Otherwise, for a one relationship:

• prototype.__create__relation_name
• prototype.__update__relation_name

where relation_name is the name of the relation.

For example, for a user model having one profile photo and many photos:

  "SetupRemoteMethods": {
    "disable": [
      "prototype.__create__profilePhoto",
      "prototype.__update__profilePhoto",
      "prototype.__create__photos",
      "prototype.__update__photos",
      "prototype.__updateById__photos",
      "prototype.__link__photos",
      "prototype.__unlink__photos"
    ]
  },

Configuration

The following configuration is added to the Loopback configuration.

  "upload": {
    "containerName": "uploadsBucket",
    "minSize": 0,
    "maxSize": 20971520
  }

This is based on the module configuration.

Storage

Filesystem

The file are stored under the folder name provided by the configuration in the storage folder. The default folder name is uploads.

The files are then available through the url http://0.0.0.0:3000/storage/uploads/unique-file-identifier.

AWS

The file are stored in the bucket provided by the configuration. The default folder name is uploads.

The files are then then available through the AWS url.

Troubleshooting

DEBUG=loopback:file-upload:* yarn start