FEATURE: Make formState initialization extendable

This adds a mechanism to hook into the form state initialization and define custom initializers.

Resolves: #152

Classes/Core/Model/FormDefinition.php

@@ -18,6 +18,8 @@
 use Neos\Form\Exception;
 use Neos\Form\Exception\IdentifierNotValidException;
 use Neos\Form\Exception\TypeDefinitionNotFoundException;
+use Neos\Form\FormState\DefaultFormStateInitializer;
+use Neos\Form\FormState\FormStateInitializerInterface;
 use Neos\Form\Utility\Arrays as FormArrays;
 use Neos\Form\Utility\SupertypeResolver;
 use Neos\Utility\Arrays;
@@ -318,6 +320,8 @@ class FormDefinition extends Renderable\AbstractCompositeRenderable
      */
     protected $finisherPresets;
 
+    protected FormStateInitializerInterface $formStateInitializer;
+
     /**
      * Constructor. Creates a new FormDefinition with the given identifier.
      *
@@ -329,13 +333,20 @@ class FormDefinition extends Renderable\AbstractCompositeRenderable
      */
     public function __construct($identifier, $formDefaults = [], $type = 'Neos.Form:Form')
     {
-        $this->formFieldTypeManager = new SupertypeResolver(isset($formDefaults['formElementTypes']) ? $formDefaults['formElementTypes'] : []);
-        $this->validatorPresets = isset($formDefaults['validatorPresets']) ? $formDefaults['validatorPresets'] : [];
-        $this->finisherPresets = isset($formDefaults['finisherPresets']) ? $formDefaults['finisherPresets'] : [];
+        $this->formFieldTypeManager = new SupertypeResolver($formDefaults['formElementTypes'] ?? []);
+        $this->validatorPresets = $formDefaults['validatorPresets'] ?? [];
+        $this->finisherPresets = $formDefaults['finisherPresets'] ?? [];
 
         if (!is_string($identifier) || strlen($identifier) === 0) {
             throw new IdentifierNotValidException('The given identifier was not a string or the string was empty.', 1325574803);
         }
+
+        $formStateInitializer = $formDefaults['formStateInitializer'] ?? DefaultFormStateInitializer::class;
+        if (!is_a($formStateInitializer, FormStateInitializerInterface::class, true)) {
+            throw new \RuntimeException(sprintf('The given class "%s" does not implement the interface %s', $formStateInitializer, FormStateInitializerInterface::class), 1648204540);
+        }
+        $this->formStateInitializer = new $formStateInitializer();
+
         $this->identifier = $identifier;
         $this->type = $type;
 
@@ -703,4 +714,13 @@ public function getValidatorPresets()
     {
         return $this->validatorPresets;
     }
+
+    /**
+     * @internal
+     * @return FormStateInitializerInterface
+     */
+    public function getFormStateInitializer(): FormStateInitializerInterface
+    {
+        return $this->formStateInitializer;
+    }
 }

Classes/Core/Runtime/FormRuntime.php

@@ -162,30 +162,14 @@ public function __construct(FormDefinition $formDefinition, ActionRequest $reque
      */
     public function initializeObject()
     {
-        $this->initializeFormStateFromRequest();
+        $this->formState = $this->formDefinition->getFormStateInitializer()->initializeFormState($this->formDefinition, $this->request);
         $this->initializeCurrentPageFromRequest();
 
         if (!$this->isFirstRequest()) {
             $this->processSubmittedFormValues();
         }
     }
 
-    /**
-     * @return void
-     * @internal
-     */
-    protected function initializeFormStateFromRequest()
-    {
-        $serializedFormStateWithHmac = $this->request->getInternalArgument('__state');
-        if ($serializedFormStateWithHmac === null) {
-            $this->formState = new FormState();
-        } else {
-            $serializedFormState = $this->hashService->validateAndStripHmac($serializedFormStateWithHmac);
-            /** @noinspection UnserializeExploitsInspection The unserialize call is safe because of the HMAC check above */
-            $this->formState = unserialize(base64_decode($serializedFormState));
-        }
-    }
-
     /**
      * @return void
      * @internal

Classes/FormState/DefaultFormStateInitializer.php

@@ -0,0 +1,40 @@
+<?php
+declare(strict_types=1);
+
+namespace Neos\Form\FormState;
+
+/*
+ * This file is part of the Neos.Form package.
+ *
+ * (c) Contributors of the Neos Project - www.neos.io
+ *
+ * This package is Open Source Software. For the full copyright and license
+ * information, please view the LICENSE file which was distributed with this
+ * source code.
+ */
+
+use Neos\Flow\Mvc\ActionRequest;
+use Neos\Flow\Security\Cryptography\HashService;
+use Neos\Form\Core\Model\FormDefinition;
+use Neos\Fusion\Form\Runtime\Domain\FormState;
+
+class DefaultFormStateInitializer implements FormStateInitializerInterface
+{
+    /**
+     * @Flow\Inject
+     * @var HashService
+     */
+    protected $hashService;
+
+    public function initializeFormState(FormDefinition $formDefinition, ActionRequest $actionRequest): FormState
+    {
+        $serializedFormStateWithHmac = $actionRequest->getInternalArgument('__state');
+        if ($serializedFormStateWithHmac !== null) {
+            $serializedFormState = $this->hashService->validateAndStripHmac($serializedFormStateWithHmac);
+            /** @noinspection UnserializeExploitsInspection The unserialize call is safe because of the HMAC check above */
+            return unserialize(base64_decode($serializedFormState));
+        }
+
+        return new FormState();
+    }
+}

Classes/FormState/FormStateInitializerInterface.php

@@ -0,0 +1,23 @@
+<?php
+declare(strict_types=1);
+
+namespace Neos\Form\FormState;
+
+/*
+ * This file is part of the Neos.Form package.
+ *
+ * (c) Contributors of the Neos Project - www.neos.io
+ *
+ * This package is Open Source Software. For the full copyright and license
+ * information, please view the LICENSE file which was distributed with this
+ * source code.
+ */
+
+use Neos\Flow\Mvc\ActionRequest;
+use Neos\Form\Core\Model\FormDefinition;
+use Neos\Fusion\Form\Runtime\Domain\FormState;
+
+interface FormStateInitializerInterface
+{
+    public function initializeFormState(FormDefinition $formDefinition, ActionRequest $actionRequest): FormState;
+}

Configuration/Settings.yaml

@@ -10,6 +10,7 @@ Neos:
         title: Default
         stylesheets: {  }
         javaScripts: {  }
+        formStateInitializer: Neos\Form\FormState\DefaultFormStateInitializer
         formElementTypes:
           'Neos.Form:Base':
             renderingOptions:

composer.json

@@ -4,7 +4,7 @@
     "license": "MIT",
     "description": "Extensible and flexible API for building web forms",
     "require": {
-        "php": ">=7.1.0",
+        "php": ">=7.4.0",
         "neos/flow": ">=6.0 || dev-master"
     },
     "replace": {