/workers-get-province-or-state

Usage

// contents of state-province.min.js
// let stateOrProvince,zipCodeCache; ...


addEventListener('fetch', event => {
  // Workers-specific handler that captures all runtime errors
  event.passThroughOnException()
  event.respondWith(handleRequest(event))
})


async function handleRequest(event) {
  // to write new headers on the request, make it mutable by instantiating a new Request
  let request = new Request(event.request) 

  // .clone() must be used to avoid locking the request stream to a Reader
  const state = stateOrProvince(request.clone())
  
  // set a header value to be visible at your origin
  request.headers.set('cf-state-province', state)

  return fetch(request)
}

Notes

  • Relies on postalCode attribute
  • If Cloudflare cannot identify the postalCode, this module falls back to the two-digit country code
  • If Cloudflare cannot identify the country, NA is returned

Demo