io-link

io-link is a webservice that generates and handles Dynamic Links that either link to a screen in a configured mobile app and to a fallback URL when the mobile app is not installed.

It contains also an endpoint to generate QR Codes that embeds dynamic links for IO App.

Development

Prerequisites

In order to build io-link in our local machine you need

• Node.js 18
• yarn 3

The preferred way to set up the local environment is using nodenv to manage Node.js installation and corepack (included with Node.js) to manage the installation of yarn.

Release management

This project uses changesets to automate updating package versions, and changelogs.

Each Pull Request that includes changes that require a version bump should include a changeset file that describe that changes.

To create a new changeset file run yarn changeset from the project root.

Useful commands

# build the project
yarn build

# run test
yarn test

# run test with coverage
yarn coverage

# format source code (using prettier)
yarn format

# run in development mode (+ watch)
# in development mode you can set environment variables
# by putting a file named `.env` in the root folder
yarn start:dev

Configuration

io-link relies on environment variables for configuration. If is the first time you work with environment variables you can learn more on Learn Environment Variables

# REQUIRED
FALLBACK_URL=the url that will be opened when the mobile app is not installed

# OPTIONAL, set to enable universal link support to iOS App
IOS_APP_ID=apple id of the mobile app (it also known as "market id")
IOS_BUNDLE_ID=bundle id of the mobile app

# OPTIONAL, set to enable universal link support to Android App
ANDROID_PACKAGE_NAME=package name of the mobile app
ANDROID_SHA_256_CERT_FINGERPRINTS=you can read these from the play console

# optional variables
PORT=defaults to 3000
NODE_ENV=defaults to production
FALLBACK_URL_ON_IOS=overrides FALLBACK_URL when the device runs iOS
FULLBACK_URL_ON_ANDROID=overrides FALLBACK_URL when the device runs Andrid

Routes

The routes that are not listed here should be considered "implementation details" and are based on infrastructural requirements to support universal links on Apple and Android devices.

Obtain a QR Code that links to app screen

GET /qrcode.png?feat=FEATURE[&payload]

This route returns a QRCode in image/png format. That contains an uniersal link to a screen of the configured app. It is mapped with the screens of IO App.

Right now feat can be:

• firma that maps to the main screen of Firma con IO. In this case it will take srid as additional query parameter to specifiy the signature request id.

Redirect to universal link

GET /open?feat=FEATURE[&payload]

Same parameters of /qrcode.png, but this generates an universal link using the given payload and then redirects to it