Validate incoming data, and respond in the user's language

While there are libraries that help us both translate messages, and validate data in an Express' server, doing both can be a bit tricky.

I created this example based on a project I recently did for an API which had to be fully translated to both English and Spanish.

• Checks the header, accepting either es_MX or en_US (which is also the default)
• Validates both the existence of the expected fields, and the validity of the data being sent to the API
• Returns either error or success messages in the user's defined language (Spanish or English at this moment)

• Postman or similar software

Check out this guide for a more thorough reading, or jump straight ahead for more concise instructions.

Live API:

https://express-i18n-api.herokuapp.com/

Express listens on /api/login and /api/forgot-password
login expects email and password; forgot-password only an email
Remember to set your headers to es_MX to see it in action in Spanish

Clone the repo, then install dependencies:

git clone https://github.com/israelmuca/express-i18n-api.git myproject
cd myproject
npm i

Run the API:

npm run start

The console should read:

App running on port 8080

While the API is running, you can also run tests with:

npm run test

Or, you can jump straight into Postman:

• Set the Method to POST
• Set the Request URL to localhost:8080/api/login or localhost:8080/api/forgot-password
• Set the Headers key to Accept-Language and the value to es_MX or en_US

The login endpoint requires email and password. The only validation that is done is that both fields exists, and the email is a valid email address ([email protected]). The forgot-password endpoint requires email. It only validates the email is valid.

• Node.js
• Express
• Express-validator
• Polyglot.js
• ❤️

• Heroku