intro.md

EDD Multi-currency currency by country switcher

The worker.js Cloudflare worker below determines the currency and sets a cookie. The PHP code reads the cookie and sets the session currency in EDD.

set-currency.php

<?php
/**
 * Set EDD currency from cookie set by Cloudflare.
 */
add_action( 'init', function() {
	if ( isset( $_COOKIE['ft_currency'] ) ) {
		$currency = $_COOKIE['ft_currency'];
		if ( in_array( $currency, [ 'EUR', 'USD' ], true ) ) {
			$current_currency = EDD()->session->get( 'currency' );
			if ( $current_currency !== $currency ) {
				EDD()->session->set( 'currency', $currency );
			}
		}
	}
} );

worker.js

addEventListener('fetch', event => {
    event.respondWith(handleRequest(event.request));
});

/**
 * Handle the fetch event.
 *
 * @param {Request} request The incoming request.
 * @return {Promise<Response>} The response.
 */
async function handleRequest(request) {
    // Clone the request to ensure it's not modified.
    const response = await fetch(request.clone());

    // Check if the 'ft_currency' cookie is already set.
    const cookie = getCookie(request, 'ft_currency');
    if (cookie) {
        return response;
    }

    // Set the currency based on the country of the visitor.
    // Cloudflare provides the country in the request headers.
    const country = request.headers.get('cf-ipcountry');
    let currency = 'USD';
    if (['AT', 'BE', 'BG', 'CY', 'CZ', 'DE', 'DK', 'EE', 'ES', 'FI', 'FR', 'GR', 'HR', 'HU', 'IE', 'IT', 'LT', 'LU', 'LV', 'MT', 'NL', 'PL', 'PT', 'RO', 'SE', 'SI', 'SK', 'GB'].includes(country)) {
        currency = 'EUR';
    }

    // Set the 'ft_currency' cookie in the response.
    const newResponse = new Response(response.body, response);
    newResponse.headers.append('Set-Cookie', `ft_currency=${currency}; path=/; HttpOnly; Secure`);

    return newResponse;
}

/**
 * Get a cookie from the request.
 *
 * @param {Request} request The request object.
 * @param {string} name The name of the cookie.
 * @return {string|null} The cookie value or null if not found.
 */
function getCookie(request, name) {
    let result = null;
    const cookieString = request.headers.get('Cookie');
    if (cookieString) {
        const cookies = cookieString.split(';');
        cookies.forEach(cookie => {
            const parts = cookie.split('=');
            if (parts[0].trim() === name) {
                result = parts[1];
            }
        });
    }
    return result;
}