Feature: #94996 - Consider all Composer installed extensions as active

See Issue #94996

Description

All TYPO3 extensions installed with Composer are now considered to be active and therefore can and will interact with TYPO3 API.

At Composer install time a persistent artifact is created, holding the information which extensions are installed and the path where these reside. This makes the typo3conf/PackageStates.php file obsolete and it is neither created nor evaluated anymore.

Any extension present in the typo3conf/ext folder, but not installed by Composer, will still be considered and marked as part of TYPO3 packages when executing composer install. The only requirement here is, that such extensions need a composer.json file nonetheless. Note this behaviour is deprecated and will be removed with TYPO3 v12.

Because all extensions present in the system are considered to be active, the Extension Manager UI is adapted to not allow changing the active state of extensions anymore for composer based instances. Respectively the commands extension:activate and extension:deactivate are disabled in Composer managed systems as well.

A new command extension:setup is introduced, which supersedes both the extension manager UI as well as the activate/deactivate commands. It performs all steps that were performed during activation and deactivation (the active-state is of course not changed).

With the command extension:setup all extensions are set up in terms of database schema changes, static data import, distribution files imports, etc. As example, requiring an additional extension and then using this command will create database tables or additional database fields the extension provides.

Any installed Composer package that defines an extra.typo3/cms section in their composer.json file will be considered a TYPO3 extension and will have full access to the TYPO3 API.

However, because these Composer packages reside in the vendor folder, they can not deliver public resources. This remains exclusive for TYPO3 extensions installed into typo3conf/ext for now - those composer packages that not only have a extra.typo3/cms section, but are also of type typo3-cms-extension.

Impact

In Composer mode this has the following impact:

The PackageStates.php file is completely ignored. When migrating projects that still have this file e.g. under version control, it is recommended to remove this file.

Projects with extensions that reside directly in typo3conf/ext, and which therefore are not installed with Composer, should consider migrating them to a local path repository. In any case, such extensions now require to have a composer.json file. This file can be created by using the according UI in the Extension Manager.

When working on a Composer based project and adding new extensions via the Composer cli tool during development, all added extensions are considered active automatically, but are not yet set up in terms of database schema changes for example. The TYPO3 cli command extension:setup needs to be executed additionally. extension:setup can and should also be used, when deploying a TYPO3 project to make sure database schema is up to date.

The Composer root project package will be recognized as a TYPO3 extension as well, if it provides a extra.typo3/cms section in its composer.json, as mentioned above. Because this package, like packages in the vendor folder isn’t accessible by the web server, the root package can not deliver public resources as well.

However, when extensions are used as root package for testing (e.g., for running unit, functional or integration tests in a CI pipeline) and these extensions have files in the Resources/Public directory, a symlink in the typo3conf/ext directory is automatically created. Additionally the package path is adapted to be inside typo3conf/ext. This allows TYPO3 to properly calculate URLs for public resources of this extension.

If the root package isn’t of type typo3-cms-extension or does not have a Resources/Public directory the absolute path to the extension remains the original path to the composer root directory and no symlink is created.

This special behaviour for root packages of type typo3-cms-extension is introduced as a temporary fix to ease extension testing. It is explicitly NOT recommended to use such a setup in production.

The ext_emconf.php file of extensions is now obsolete and therefore completely ignored in Composer based instances. Make sure the information in the composer.json file is in sync with the one in your ext_emconf.php file in case you want to provide one for compatibility with non Composer mode.