Catching error if a user hasn't been subscribed.

[sujeet-agrahari]

I am using laravel 5.2.
I have nearly 15k users in my db. I used to send notification to each user based on their registered token. 1000 user at a time along with their token and the message It was taking so long.

Now I am trying to create a common topic for now, and I will subscribe every user to this topic.
I created a simple script to subscribe them all. I know I can't subscribe more than 1000 users at a time.
It's obvious there is many reasons that a user has not been subscribed. for example .
The token has expired.

Here is the code to subscribe all the users.

//Start subscribing all user to a common topic
            //collect all users tokens
            $results = User::select( 'regId')
                            ->get()->toArray();
            $user_tokens = array(); 
            foreach($results as $result) {
                array_push($user_tokens, $result['regId']);
            }
            //subscribe all users in batches
            $batch_size = 1000; // 1000 per request

            $iterations = ceil(count($user_tokens) / $batch_size); // determine how many iterations are needed
            
            for ($i = 0; $i < $iterations; $i++) {
                $offset = $i * $batch_size;
                $batch_of_1000_user_ids = array_slice($user_tokens, $offset, $batch_size);
            
                $messaging->subscribeToTopic('test', $batch_of_1000_user_ids);
            }
//End sbuscribing all users to a common topic 

So I want to know.
How can I know if a user is successfully subscribed?
Does this method $messaging->subscribeToTopic('test', $batch_of_1000_user_ids); generate any error if a user hasn't been subscribed.
Also, does this process stops if a user hasn't been subscribed succsessfuly?
for example - suppose first nth user are subscribed, and there is an error on n+1rst user in that case what will happen . Will this method skip that user and continue subscribing rest users.
It will be easier for me to track how many users has not been subscribed.

I found some reference on the docs on Validate messages Section , but I am not sure if this will work in this case.

try {
    $firebase->getMessaging()->validate($message);
} catch (InvalidMessage $e) {
    print_r($e->errors());
}

[jeromegamez]

If the request goes through (= no exception has been thrown) you can expect the subscription to be successful.

As for the error cases, unfortunately, I cannot be sure at the moment what happens when one of the tokens "in the middle" of a request fails, so I can't tell you with certainty if the rest still is subscribed, or if the whole process fails.

You can check to which topics a token (=App Instance) is subscribed with https://firebase-php.readthedocs.io/en/latest/cloud-messaging.html#working-with-topic-subscriptions

I hope this helps