Breaking: #98032 - Serializable Interface fully removed

See forge#98032

Description

The Serializable interface has been deprecated, and is slated for removal entirely in PHP 9. The preferred serialization tool is the __serialize/__unserialize method pair.

All serializable classes in TYPO3 Core already implement __serialize/__unserialize, which is automatically used by PHP in place of Serializable. The now-vestigial Serializable references have been removed.

Impact

Generally none, unless a text string of an object serialized in TYPO3 v10 or earlier (using Serializable) is deserialized in TYPO3 v12, in which case it will not deserialize correctly due to the different string format used by Serializable. That is extremely unlikely to happen.

The use of Serializable in extensions is not recommended anymore, and will be removed from PHP in version 9.

Affected Installations

None.

Migration

None needed.