[TASK] Finish class alias movings
[Packages/TYPO3.CMS.git] / typo3 / sysext / core / Documentation / Changelog / master / Breaking-63437-ClassAliasesMovedToLegacyExtension.rst
1 ==========================================================
2 Breaking: #63437 - Class aliases moved to legacy extension
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4
5 Description
6 ===========
7
8 With the switch to namespaced classes in TYPO3 CMS 6.0, a class alias mechanism
9 has been set up to support the old class names as aliases for a while. All those
10 class aliases are now moved to the dedicated extension "compatibility6". This
11 extension will be removed from the core with in the future TYPO3 CMS 7 development.
12
13 Removing the class aliases from the core results in a significant performance gain
14 especially during first load with empty caches.
15
16
17 Impact
18 ======
19
20 If extensions still rely on old non-namespaced class names, ext:compatibility can
21 be loaded to keep further backwards compatibility for now - with the side effect of
22 drained performance.
23
24 Affected installations
25 ======================
26
27 TYPO3 CMS 7 installations need compatibility6 extension loaded if old extensions are
28 used that are still not adapted to the namespaced core classess.
29
30 Migration
31 =========
32
33 During upgrading, the "Extension check" of the install tool may find old extensions that
34 still rely on old class names and can unload those. The backend may work again to load
35 extension "compatibility6", or to unload further extensions that rely on old class names.
36
37 Another option is to manually set all extensions that rely on old class names to "inactive"
38 in typo3conf/PackageStates.php, or to set compatibility6 to "active". If a manual change is
39 done, typo3temp/Cache directory should be deleted afterwards.