Doctrine OneToMany with aggregate field, how to keep it up to date? - collections

Question

In doctrine2 I have a OneToMany association: One Application <=> Many ApplicationCost
// Application.php
/**
* #ORM\OneToMany(targetEntity="ApplicationCost", mappedBy="application", orphanRemoval=true)
*/
protected $costs;
// ApplicationCost.php
/**
* #ORM\ManyToOne(targetEntity="Application", inversedBy="costs")
* #ORM\JoinColumn(name="application_id", referencedColumnName="id")
*/
protected $application;
In Application entity I have an agregate field sumCosts:
/**
* #ORM\Column(type="decimal", scale=2)
*/
protected $sumCosts;
Which is updated when addCost and removeCost are called:
// Application.php
public function addCost(ApplicationCost $cost)
{
if (!$this->costs->contains($cost)) {
$this->sumCosts += $cost->getBalance();
$this->costs[] = $cost;
$cost->setApplication($this);
}
return $this;
}
public function removeCost(ApplicationCost $cost)
{
if ($this->costs->contains($cost)) {
$this->sumCosts -= $cost->getBalance();
$this->costs->removeElement($cost);
}
}
Assuming User can edit already existing ApplicationCost's and can change it's parent Application, how do I make sure that this agregate field is up to date?
My approach is:
// ApplicationCost.php
public function setApplication(Application $application = null)
{
if ($this->application !== null) {
$this->application->removeCost($this);
}
if ($application !== null) {
$application->addCost($this);
}
$this->application = $application;
return $this;
}
Is that good? Or am I makeing here some huge mistake here and sumCosts may be out of sync?
EDIT: I've read Doctrine's Aggregate Fields cookbook and I have the versioning (and I use locking mechanism). My question is not about concurrency.
EDIT: I've created some tests
public function testSumCosts()
{
$app = new Application();
$costA = new ApplicationCost();
$costA->setBalance(150);
$costB = new ApplicationCost();
$costB->setBalance(100);
$costC = new ApplicationCost();
$costC->setBalance(50);
$app->addCost($costA);
$app->addCost($costB);
$app->addCost($costC);
$app->removeCost($costC);
$this->assertEquals(250, $app->sumCosts(), 'Costs are summed correctly');
}
public function testCostsChangeApplication()
{
$appA = new Application();
$appB = new Application();
$costA = new ApplicationCost();
$costA->setBalance(100);
$costB = new ApplicationCost();
$costB->setBalance(50);
$appA->addCost($costA);
$appB->addCost($costB);
$costA->setApplication($appB);
$costB->setApplication(null);
$this->assertEquals(0, $appA->sumCosts(), 'Costs are removed correctly');
$this->assertEquals(100, $appB->sumCosts(), 'Costs are added correctly');
}
And after adding $cost->setApplication($this); to addEntry both tests are green. Though I still wonder if I might have missed something.

Answer 1

Okay, I think I finally achieved desired result. I'll describe it for future reference and anyone who might have the same problem:
First of all correct the class
// Application.php
public function addCost(ApplicationCost $cost)
{
if (!$this->costs->contains($cost)) {
$this->sumCosts += $cost->getBalance();
}
$this->costs[] = $cost;
return $this;
}
public function removeCost(ApplicationCost $cost)
{
if ($this->costs->contains($cost)) {
$this->sumCosts -= $cost->getBalance();
}
$this->costs->removeElement($cost);
}
If you compare this to my original code you'll see that only updateing the agregate field is under condition. It does not hurt as collections can't hold duplicate elements and can't remove non existing elements.
Second of all, configure the cascade={all} option on inverse side of association (that is, on costs inside Application.php). So whenever you add/remove costs they are persisted too.
to be continued... (have to test what happens when i change application it from the owning side and persist only ApplicationCost -> will both old and new Application be updated?)