in src/MQTTDisplay.js [86:97]
function handleSubscriptionRequest(e) {
// stop submit button from refreshing entire page
e.preventDefault();
if (subscribedTopics.includes(desiredSubscriptionTopic)) {
console.log(`You are already subscribed to topic '${desiredSubscriptionTopic}'!`);
}
else {
setSubscribedTopics(prevTopics => [...prevTopics, desiredSubscriptionTopic]);
console.log(`Subscribed to topic '${desiredSubscriptionTopic}'!`);
}
}