I am sending notification to mobile device for which I have fcm tokens. On sending, I get a response that can for each fcm token have an error. I want to remove the invalid tokens that for sure will no longer work, but keep tokens that may have failed this time and could still work in the future.
I am using the node-gcm package.
What are the possible values for the error field in the response of each token.
What checks on this value should I be making to only delete the permanently invalid tokens ?
sender.send(gcmMessage, { registrationTokens: fcmTokens }, (error, response) => {
if (error) {
console.log(error);
} else {
const failedTokens = fcmTokens.filter((_, index) => response.results[index].error != null);
if (failedTokens.length) {
// If there are failed tokens, check these to know whether we should delete them.
this.clearUserFcmTokens(userID, failedTokens);
}
}
});
The two most common error codes that indicate that the token should be removed are messaging/invalid-registration-token and messaging/registration-token-not-registered.
I recommend basing your logic on this code in the functions-samples repo.
I got an answer from the repo itself.
They recommend checking if the error matches 'NotRegistered'.
I've modified the code to check 'NotRegistered' and 'InvalidRegistration':
sender.send(gcmMessage, { registrationTokens: fcmTokens }, (error, response) => {
if (error) {
console.log(error);
} else {
const invalidTokenErrorKeys = ['NotRegistered', 'InvalidRegistration'];
const failedTokens = fcmTokens.filter((_, index) => response.results[index].error != null && invalidTokenErrorKeys.includes(response.results[index].error));
if (failedTokens.length) {
this.clearUserFcmTokens(userID, failedTokens);
}
}
});
The values of the error field match the HTTP Code column from this link:
https://firebase.google.com/docs/cloud-messaging/http-server-ref#error-codes
examples: InvalidRegistration, NotRegistered, MessageTooBig, Unavailable etc.
Issue and response on the repo https://github.com/ToothlessGear/node-gcm/issues/360