64 lines
2.0 KiB
Plaintext
64 lines
2.0 KiB
Plaintext
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As explained in the [restrictions for entity classes in the manual](http://www.doctrine-project.org/documentation/manual/2_0/en/architecture#entities),
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it is usually not allowed for an entity to implement `__wakeup` or `__clone`, because Doctrine
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makes special use of them. However, it is quite easy to make use of these methods in a safe way
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by guarding the custom wakeup or clone code with an entity identity check, as demonstrated in the following sections.
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++ Safely implementing __wakeup
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To safely implement `__wakeup`, simply enclose your implementation code in an identity check
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as follows:
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[php]
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class MyEntity
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{
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private $id; // This is the identifier of the entity.
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//...
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public function __wakeup()
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{
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// If the entity has an identity, proceed as normal.
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if ($this->id) {
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// ... Your code here as normal ...
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}
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// otherwise do nothing, do NOT throw an exception!
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}
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//...
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}
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++ Safely implementing __clone
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Safely implementing `__clone` is pretty much the same:
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[php]
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class MyEntity
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{
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private $id; // This is the identifier of the entity.
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//...
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public function __clone()
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{
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// If the entity has an identity, proceed as normal.
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if ($this->id) {
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// ... Your code here as normal ...
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}
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// otherwise do nothing, do NOT throw an exception!
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}
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//...
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}
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++ Summary
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As you have seen, it is quite easy to safely make use of `__wakeup` and `__clone` in your entities
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without adding any really Doctrine-specific or Doctrine-dependant code.
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These implementations are possible and safe because when Doctrine invokes these methods,
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the entities never have an identity (yet). Furthermore, it is possibly a good idea to check
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for the identity in your code anyway, since it's rarely the case that you want to unserialize
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or clone an entity with no identity.
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