doctrine2 entity number in month generation - doctrine-orm

Question

I've got Invoice entity, in which I'd like to generate subsequent numbers within a given month.
Entity code:
/**
* Class Invoice
* #package App\Entity
* #ORM\Entity()
* #ORM\HasLifecycleCallbacks()
*/
class Invoice
{
(...)
/**
* #var int
* #ORM\Column(type="integer")
*/
private $year;
/**
* #var int
* #ORM\Column(type="integer")
*/
private $month;
/**
* #var int
* #ORM\Column(type="integer")
* #ORM\GeneratedValue(strategy="CUSTOM")
* #ORM\CustomIdGenerator(class="App\Helper\InvoiceNumberGenerator")
*/
private $counter;
(...)
/**
* #ORM\PrePersist
* #ORM\PreUpdate
*/
public function numberGenerator()
{
if ($this->getYear() === null) {
$this->setYear(date('Y'));
$this->setMonth(date('m'));
}
}
And App\Helper\InvoiceNumberGenerator code is:
<?php
namespace App\Helper;
use App\Entity\Invoice;
use Doctrine\Common\Persistence\ObjectRepository;
use Doctrine\ORM\EntityManager;
use Doctrine\ORM\EntityRepository;
use Doctrine\ORM\Id\AbstractIdGenerator;
use Exception;
class InvoiceNumberGenerator extends AbstractIdGenerator
{
/**
* Generates an invoice number
*
* #param EntityManager $em
* #param Invoice $entity
* #return mixed
* #throws Exception
*/
public function generate(EntityManager $em, $entity)
{
if (!$entity instanceof Invoice) {
throw new Exception('Generator służy tylko do generowania numerów faktur.');
}
/** #var ObjectRepository | EntityRepository $invoiceRepository */
$invoiceRepository = $em->getRepository(Invoice::class);
/** #var Invoice $lastInvoice */
$lastInvoice = $invoiceRepository->findOneBy(
array(
'year' => $entity->getYear(),
'month' => $entity->getMonth()
),
array(
'counter' => 'desc'
)
);
if (empty($lastInvoice)) {
return 1;
}
return $lastInvoice->getCounter() + 1;
}
}
When I dump $lastInvoice, it shows:
Invoice {#5522 ▼
-id: 1
-generated: false
-fileName: "example"
-year: 2019
-month: 11
-counter: 1
-name: "AG"
-company: "Gall"
-address: "Street 1"
-address2: "Gliwice"
-nip: "6314567890"
-reservation: Reservation {#5855 ▶}
-date: null
}
So it looks like the generator gets to selecting last one correctly, but nevertheless I got error when trying to create new Invoice:
SQLSTATE[23000]: Integrity constraint violation: 1048 Column 'counter'
cannot be null
Any advise on what I'm doing wrong?

Answer 1

the #CustomIdGenerator annotation is only called when the column is also marked with #Id. From the docs:
This annotations allows you to specify a user-provided class to generate identifiers. This annotation only works when both #Id and #GeneratedValue(strategy="CUSTOM") are specified.
Ids are always a special kind of thing and thus must sometimes be perfect before inserting. To solve your problem - because the counter is not an id column -, you could use lifecycle events instead (prePersist, probably) and use the event's entity manager in an event listener/subscriber to run your query.