Deprecation: #97435 - Usage of SiteLanguageAwareTrait to denote site language awareness

See Issue #97435

Description

The TYPO3\CMS\Core\Site\SiteLanguageAwareTrait should not be used as means to denote a class as aware of the site language anymore. Instead, the TYPO3\CMS\Core\Site\SiteLanguageAwareInterface should be implemented for this purpose. The trait is an internal implementation and should not be used in user land code.

Impact

If you are currently using the SiteLanguageAwareTrait to denote a class as aware of the site language, you should implement the SiteLanguageAwareInterface instead.

Affected Installations

All installations where the SiteLanguageAwareTrait is used to denote a class as aware of the site language.

Migration

Change classes that use the SiteLanguageAwareTrait but not the corresponding interface to implement the interface. Replace the usage of the trait with an own trait, or implement the interface methods directly in the class.

Example before the migration:

use TYPO3\CMS\Core\Site\SiteLanguageAwareTrait;

class MyClass
{
    use SiteLanguageAwareTrait;
}

Example after the migration:

use TYPO3\CMS\Core\Site\SiteLanguageAwareInterface;
use TYPO3\CMS\Core\Site\Entity\SiteLanguage;

class MyClass implements SiteLanguageAwareInterface
{

    protected SiteLanguage $siteLanguage;

    public function setSiteLanguage(SiteLanguage $siteLanguage)
    {
        $this->siteLanguage = $siteLanguage;
    }

    public function getSiteLanguage(): SiteLanguage
    {
        return $this->siteLanguage;
    }
}