Feature: #67229 - FormEngine NodeFactory API

See Issue #67229

Description

The FormEngine class construct was moved to a tree approach with container classes as inner nodes and element classes (the rendering widgets) as leaves. Finding, instantiation and preparation of those classes is done via TYPO3\CMS\Backend\Form\NodeFactory .

This class was extended with an API to allow flexible overriding and adding of containers and elements:

Registration of new nodes and overwriting existing nodes

$GLOBALS['TYPO3_CONF_VARS']['SYS']['formEngine']['nodeRegistry'][1433196792] = array(
        'nodeName' => 'input',
        'priority' => 40,
        'class' => \MyVendor\MyExtension\Form\Element\T3editorElement::class,
);

This registers the class MyVendor\MyExtension\Form\Element\T3editorElement as render class for the type input . It will be called to render elements of this type and must implement the interface TYPO3\CMS\Backend\Form\NodeInterface . The array key is the unix timestamp of the date when an registry element is added and is just used to have a unique key that is very unlikely to collide with others - this is the same logic that is used for exception codes. If more than one registry element for the same type is registered, the element with highest priority wins. Priority must be set between 0 and 100. Two elements with same priority for the same type will throw an exception.

The core extension t3editor uses this API to substitute a type=text field with renderType=t3editor from the default TextElement to its own T3editorElement .

This registry both allows completely overriding existing implementations of any existing given type as well as registration of a new renderType for own fancy elements. A TCA configuration for a new renderType and its nodeRegistry could look like:

'columns' => array(
        'bodytext' => array(
                'config' => array(
                        'type' => 'text',
                        'renderType' => '3dCloud',
                ),
        ),
),

$GLOBALS['TYPO3_CONF_VARS']['SYS']['formEngine']['nodeRegistry'][1433197759] = array(
        'nodeName' => '3dCloud',
        'priority' => 40,
        'class' => \MyVendor\MyExtension\Form\Element\ShowTextAs3dCloudElement::class,
);

Resolve class resolution to different render classes

In case the above API is not flexible enough, another class can be registered to resolve the final class that renders a certain element or container differently:

// Register FormEngine node type resolver hook to render RTE in FormEngine if enabled
$GLOBALS['TYPO3_CONF_VARS']['SYS']['formEngine']['nodeResolver'][1433198160] = array(
        'nodeName' => 'text',
        'priority' => 50,
        'class' => \MyVendor\MyExtension\Form\Resolver\MyTextNodeResolver::class,
);

This registers a resolver class at priority 50 if the type text should be rendered. This class must implement TYPO3\CMS\Backend\Form\NodeResolverInterface and can return a different class name that is called as render class. The render class in turn must implement TYPO3\CMS\Backend\Form\NodeInterface .

The array key is a unix timestamp of the date when this resolver code is registered. Multiple resolvers are a chain, the resolver with highest priority is asked first, and the chain is called until one resolver returns a new class name. If no resolver returns anything, the default class name will be instantiated and rendered.

Priority is between 0 and 100 and two resolvers for the same type and same priority will throw an exception.

The resolver will receive the full globalOptions array with all settings to make a resolve decision on all incoming values.

This API is used by core extension rtehtmlarea to route the rendering of type=text to its own RichTextElement class in case the editor is enabled for this field and for the user.

This API allows fine grained resolution of render-nodes based on any need, for instance it would be easily possible to call another different richtext implementation (eg. TinyMCE) for specific fields of own extensions based on moon phases or your fathers birthday, by adding a resolver class with a higher priority.

Warning

The internal data given to the resolver class still may change. Both the globalOptions and the current renderType values are subject to change without further notice until TYPO3 CMS 7 LTS.