Symfony form edit - php

Question

I use Symfony 3.
I have an entity (Book) that I can create and edit. So I have created two actions and forms to do this. But, I want to save historical of this change.
I have imagine a solution. Two Entity, Book and SubBook to inherit of BaseBook. SubBook is the history of all edit of Book and is linked by a field "parent".
public function editAction(Request $request, ...)
{
$book = ...
$form = $this->createForm(BookType::class, $book);
$form->handleRequest($request);
if ($form->isSubmitted() && $form->isValid()) {
$subbook = new SubBook($book);
$em = $this->getDoctrine()->getManager();
$em->persist($subbook);
$em->flush();
// ...
}
// ...
}
AppBundle/Entity/Book
class Book extends BaseBook {
// ...
}
AppBundle/Entity/SubBook
class SubBook extends BaseBook {
// ...
public function __construct($book)
{
parent::__construct();
// ...
$this->parent = $book;
}
}
AppBundle/Model/BaseBook
abstract class BaseBook
{
// ...
}
But my problem is that when I submit the edit form, my Book ($book) is automatically persist when I execute $em->flush(); so it is updated even if I don't execute $em->persist($book);.
So, do you have any idea to do this ? or to solve this error ?
Thanks !

Answer 1

You should use $em->detach($book);. You can find more information in the documentation

Answer 2

So, I finally did this. My Book is the entity with last update and I save in an SubBook entity all values that have changed.
My SubBook entity is so almost like Book but all value (not changed) can be null. So I abandoned the model.
public function editAction(Request $request, $id)
{
$book = ...
$form = ...
if ($form->isSubmitted() && $form->isValid()) {
$em = $this->getDoctrine()->getManager();
$uow = $em->getUnitOfWork();
$uow->computeChangeSets();
$changeset = $uow->getEntityChangeSet($book);
$subbook = new SubBook($book, $changeset);
$em->persist($subbook);
$em->persist($book);
$em->flush();
// ...
}
// ...
}
AppBundle/Entity/SubBook
public function __construct($book, $changeset)
{
// ...
$this->parent = $book;
foreach ($changeset as $key => $values) {
$this->$key = $values[0]; // values[0] => Hold value, [1] => New value
}
}