Laravel notify user with results when batched jobs have finished - laravel

Question

I want to email a potentially large number of clients, so I am using Batches and pushing each email send as a batched job, like this:
public function __construct(RunReport $runReport, User $run_by) {
$this->runReport = $runReport;
$this->run_by = $run_by;
}
public function handle()
{
$company_detail = CompanyDetail::first();
$jobs = $this->runReport->runReportReportees
->map(fn(RunReportReportee $runReportReportee) => new EmailStatementJob($runReportReportee, $company_detail))
->toArray();
$batch = Bus
::batch($jobs)
->then(function(Batch $batch) {
// All completed
$completed = ($batch->totalJobs - $batch->failedJobs);
$message = "foo";
$type = "bar";
$this->run_by->notify(new GenericNotification($message, $type, 'envelope'));
})
->allowFailures()
->name('Batch name here trust me')
->dispatch();
return $batch->id;
}
However the notify line causes an error Serialization of 'Doctrine\DBAL\Driver\PDOConnection' is not allowed.
How can I notify the user that initiated the batch when the batch is finished, with the results of the included email send attempts? Alternatively, how else should I email a few hundred clients and notify the user of the results?

Answer 1

I figured it out eventually with help - I was using $this in the ->then() callback which was my first mistake. Then instead of the notification in the job, I have instead stored the user ID and passed it to the then() callback like this
->then(function(Batch $batch) use ($run_by_id) { ... }
In the callback instead of notifying the user, I call an event
event(new HcpStatementsBatchFinishedEvent($batch, $id));
The event simply stores the information
public function __construct(Batch $batch, int $run_by_sysid)
{
$this->run_by = User::find($run_by_id);
$this->batch = $batch;
}
And the listener for the event builds the message and notifies the user.