Deprecation: #95164 - ext:backend BackendTemplateView

See Issue #95164

Description

To simplify and align the view part of Extbase based backend module controller code with non-extbase based controllers, class TYPO3\CMS\Backend\View\BackendTemplateView has been marked as deprecated and will be removed in TYPO3 v12.

This follows the general core strategy to have document header related code using the ModuleTemplate class structure within controllers directly, while Extbase views render only the main body part.

Impact

Extensions should switch away from using BackendTemplateView. By hiding an instance of ModuleTemplate class, BackendTemplateView basically added a no longer needed level of indirection to code that should be located directly within controller actions.

Together with the TYPO3 v11 requirement within Extbase controller actions to return responses directly, combined with Extbase Request object now implementing the PSR-7 ServerRequestInterface, and with the deprecation of other doc header related Fluid View helpers, Extbase controller action become much more obvious codewise.

Affected Installations

Instances with extensions using class BackendTemplateView are affected. Candidates are typically Extbase based extensions that deliver backend modules. The extension scanner will find usages as strong match.

Migration

A transition away from BackendTemplateView should be usually pretty straight: Instead of retrieving a ModuleTemplate instance from the view, the ModuleTemplateFactory should be injected and an instance retrieved using create().

A typical scenario before:

class MyController extends ActionController
{
    protected $defaultViewObjectName = BackendTemplateView::class;

    public function myAction(): ResponseInterface
    {
        $this->view->assign('someVar', 'someContent');
        $moduleTemplate = $this->view->getModuleTemplate();
        // Adding title, menus, buttons, etc. using $moduleTemplate ...
        return $this->htmlResponse();
    }
}

Dropping BackendTemplateView leads to code similar to this:

class MyController extends ActionController
{
    protected ModuleTemplateFactory $moduleTemplateFactory;

    public function __construct(
        ModuleTemplateFactory $moduleTemplateFactory,
    ) {
        $this->moduleTemplateFactory = $moduleTemplateFactory;
    }

    public function myAction(): ResponseInterface
    {
        $this->view->assign('someVar', 'someContent');
        $moduleTemplate = $this->moduleTemplateFactory->create($this->request);
        // Adding title, menus, buttons, etc. using $moduleTemplate ...
        $moduleTemplate->setContent($this->view->render());
        return $this->htmlResponse($moduleTemplate->renderContent());
    }
}