
.. include:: /Includes.rst.txt

=============================================
Breaking: #69568 - FormEngine related classes
=============================================

See :issue:`69568`

Description
===========

The following classes have been removed:

* `\TYPO3\CMS\Backend\Form\DataPreprocessor`
* `\TYPO3\CMS\Backend\Form\FormEngine`
* `\TYPO3\CMS\Backend\Form\FlexFormsHelper`

The following hook has been removed:

* `$GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['t3lib/class.t3lib_tceforms.php']['getMainFieldsClass']`


Impact
======

Code trying to instantiate these classes will fatal.


Affected Installations
======================

A rather low number of extensions should be affected by this change. Searching for the
above class names should reveal them.


Migration
=========

The methods and classes have been moved to different classes and solutions.
Extensions needs adaption.

The hook `getMainFieldsClass` has been substituted with a much more fine grained and flexible API.
Use `FormDataProvider` to change data given to the render engine of FormEngine from now on.


.. index:: PHP-API, Backend
