77 lines
2.2 KiB
ReStructuredText
77 lines
2.2 KiB
ReStructuredText
Implementing Wakeup or Clone
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============================
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.. sectionauthor:: Roman Borschel (roman@code-factory.org)
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As explained in the
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:doc:`restrictions for document classes in the manual <../reference/architecture>`.
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it is usually not allowed for a document to implement ``__wakeup``
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or ``__clone``, because Doctrine makes special use of them.
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However, it is quite easy to make use of these methods in a safe
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way by guarding the custom wakeup or clone code with a document
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identity check, as demonstrated in the following sections.
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Safely implementing \_\_wakeup
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------------------------------
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To safely implement ``__wakeup``, simply enclose your
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implementation code in an identity check as follows:
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.. code-block:: php
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<?php
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class MyDocument
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{
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private $id; // This is the identifier of the document.
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//...
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public function __wakeup()
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{
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// If the document has an identity, proceed as normal.
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if ($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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-----------------------------
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Safely implementing ``__clone`` is pretty much the same:
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.. code-block:: php
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<?php
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class MyDocument
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{
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private $id; // This is the identifier of the document.
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//...
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public function __clone()
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{
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// If the document has an identity, proceed as normal.
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if ($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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-------
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As you have seen, it is quite easy to safely make use of
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``__wakeup`` and ``__clone`` in your documents without adding any
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really Doctrine-specific or Doctrine-dependant code.
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These implementations are possible and safe because when Doctrine
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invokes these methods, the documents never have an identity (yet).
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Furthermore, it is possibly a good idea to check for the identity
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in your code anyway, since it's rarely the case that you want to
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unserialize or clone a document with no identity. |