Fixed exception about non-persisted entities, when using the cached StructuralEntityType.

src/Controller/AdminPages/BaseAdminController.php

@@ -72,6 +72,9 @@ abstract class BaseAdminController extends AbstractController
             $em->flush();
         }
 
+        //Rebuild form, so it is based on the updated data. Important for the parent field!
+        $form = $this->createForm($this->form_class, $entity);
+
         return $this->render($this->twig_template, [
             'entity' => $entity,
             'form' => $form->createView()

src/Form/Part/PartLotType.php

@@ -37,12 +37,15 @@ use App\Entity\Parts\PartLot;
 use App\Entity\Parts\Storelocation;
 use App\Form\Type\StructuralEntityType;
 use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\DataMapperInterface;
+use Symfony\Component\Form\Exception;
 use Symfony\Component\Form\Extension\Core\Type\CheckboxType;
 use Symfony\Component\Form\Extension\Core\Type\DateTimeType;
 use Symfony\Component\Form\Extension\Core\Type\IntegerType;
 use Symfony\Component\Form\Extension\Core\Type\NumberType;
 use Symfony\Component\Form\Extension\Core\Type\TextType;
 use Symfony\Component\Form\FormBuilderInterface;
+use Symfony\Component\Form\FormInterface;
 use Symfony\Component\OptionsResolver\OptionsResolver;
 use function GuzzleHttp\Promise\queue;
 
@@ -55,7 +58,8 @@ class PartLotType extends AbstractType
 
         $builder->add('storage_location', StructuralEntityType::class, ['class' => Storelocation::class,
             'label' => 'part_lot.edit.location',
-            'disable_not_selectable' => true, 'attr' => ['class' => 'form-control-sm']]);
+            'disable_not_selectable' => true,
+            'attr' => ['class' => 'selectpicker form-control-sm', 'data-live-search' => true]]);
 
         $builder->add('amount',NumberType::class, [ 'html5' => true,
             'label' => 'part_lot.edit.amount',

src/Form/Type/StructuralEntityType.php

@@ -38,13 +38,19 @@ use App\Repository\StructuralDBElementRepository;
 use App\Services\TreeBuilder;
 use Doctrine\ORM\EntityManagerInterface;
 use Symfony\Component\Form\AbstractType;
+use Symfony\Component\Form\CallbackTransformer;
 use Symfony\Component\Form\ChoiceList\Loader\CallbackChoiceLoader;
+use Symfony\Component\Form\DataMapperInterface;
+use Symfony\Component\Form\DataTransformerInterface;
+use Symfony\Component\Form\Exception;
+use Symfony\Component\Form\Exception\TransformationFailedException;
 use Symfony\Component\Form\Extension\Core\Type\ChoiceType;
 use Symfony\Component\Form\FormBuilderInterface;
 use Symfony\Component\Form\FormInterface;
 use Symfony\Component\Form\FormView;
 use Symfony\Component\OptionsResolver\Options;
 use Symfony\Component\OptionsResolver\OptionsResolver;
+use function foo\func;
 
 /**
  * This class provides a choice form type similar to EntityType, with the difference, that the tree structure
@@ -64,10 +70,19 @@ class StructuralEntityType extends AbstractType
         $this->builder = $builder;
     }
 
+    public function buildForm(FormBuilderInterface $builder, array $options)
+    {
+        $builder->addModelTransformer(new CallbackTransformer(
+            function ($value) use ($options){
+                return $this->transform($value, $options);
+            }, function ($value) use ($options) {
+                return $this->reverseTransform($value, $options);
+        }));
+    }
+
     public function configureOptions(OptionsResolver $resolver)
     {
         $resolver->setRequired(['class']);
-
         $resolver->setDefaults(['attr' => ['class' => 'selectpicker', 'data-live-search' => true],
             'show_fullpath_in_subtext' => true, //When this is enabled, the full path will be shown in subtext
             'subentities_of' => null,   //Only show entities with the given parent class
@@ -128,7 +143,6 @@ class StructuralEntityType extends AbstractType
 
         $choices = $this->builder->typeToNodesList($options['class'], null);
 
-
         /** @var StructuralDBElementRepository $repo */
         /*$repo = $this->em->getRepository($options['class']);
         $choices = $repo->toNodesList(null); */
@@ -142,11 +156,101 @@ class StructuralEntityType extends AbstractType
         //See extendedBootstrap4_layout.html.twig for that...
         $view->vars['use_html_in_labels'] = true;
 
-        parent::buildView($view, $form, $options); // TODO: Change the autogenerated stub
+        parent::buildView($view, $form, $options);
     }
 
     public function getParent()
     {
         return ChoiceType::class;
     }
+
+    /**
+     * Transforms a value from the original representation to a transformed representation.
+     *
+     * This method is called when the form field is initialized with its default data, on
+     * two occasions for two types of transformers:
+     *
+     * 1. Model transformers which normalize the model data.
+     *    This is mainly useful when the same form type (the same configuration)
+     *    has to handle different kind of underlying data, e.g The DateType can
+     *    deal with strings or \DateTime objects as input.
+     *
+     * 2. View transformers which adapt the normalized data to the view format.
+     *    a/ When the form is simple, the value returned by convention is used
+     *       directly in the view and thus can only be a string or an array. In
+     *       this case the data class should be null.
+     *
+     *    b/ When the form is compound the returned value should be an array or
+     *       an object to be mapped to the children. Each property of the compound
+     *       data will be used as model data by each child and will be transformed
+     *       too. In this case data class should be the class of the object, or null
+     *       when it is an array.
+     *
+     * All transformers are called in a configured order from model data to view value.
+     * At the end of this chain the view data will be validated against the data class
+     * setting.
+     *
+     * This method must be able to deal with empty values. Usually this will
+     * be NULL, but depending on your implementation other empty values are
+     * possible as well (such as empty strings). The reasoning behind this is
+     * that data transformers must be chainable. If the transform() method
+     * of the first data transformer outputs NULL, the second must be able to
+     * process that value.
+     *
+     * @param mixed $value The value in the original representation
+     *
+     * @return mixed The value in the transformed representation
+     *
+     * @throws TransformationFailedException when the transformation fails
+     */
+    public function transform($value, $options)
+    {
+        return $value;
+    }
+
+    /**
+     * Transforms a value from the transformed representation to its original
+     * representation.
+     *
+     * This method is called when {@link Form::submit()} is called to transform the requests tainted data
+     * into an acceptable format.
+     *
+     * The same transformers are called in the reverse order so the responsibility is to
+     * return one of the types that would be expected as input of transform().
+     *
+     * This method must be able to deal with empty values. Usually this will
+     * be an empty string, but depending on your implementation other empty
+     * values are possible as well (such as NULL). The reasoning behind
+     * this is that value transformers must be chainable. If the
+     * reverseTransform() method of the first value transformer outputs an
+     * empty string, the second value transformer must be able to process that
+     * value.
+     *
+     * By convention, reverseTransform() should return NULL if an empty string
+     * is passed.
+     *
+     * @param mixed $value The value in the transformed representation
+     *
+     * @return mixed The value in the original representation
+     *
+     * @throws TransformationFailedException when the transformation fails
+     */
+    public function reverseTransform($value, $options)
+    {
+        /* This step is important in combination with the caching!
+           The elements deserialized from cache, are not known to Doctrinte ORM any more, so doctrine thinks,
+           that the entity has changed (and so throws an exception about non-persited entities).
+           This function just retrieves a fresh copy of the entity from database, so doctrine detect correctly that no
+           change happened.
+           The performance impact of this should be very small in comparison of the boost, caused by the caching.
+        */
+
+        if ($value === null) {
+            return null;
+        }
+
+        $entity = $this->em->find($options['class'], $value->getID());
+
+        return $entity;
+    }
 }