added batch work log

src/Plugin/Validation/Constraint/BatchWorkBatchesConstraint.php

@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\farm_agrikern\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+
+/**
+* Provides a BatchWorkBatches constraint.
+*
+* @Constraint(
+*   id = "AgriKernBatchWorkBatches",
+*   label = @Translation("BatchWorkBatches", context = "Validation"),
+* )
+*
+* @DCG
+* To apply this constraint on third party entity types implement either
+* hook_entity_base_field_info_alter() or hook_entity_bundle_field_info_alter().
+*
+* @see https://www.drupal.org/node/2015723
+*/
+final class BatchWorkBatchesConstraint extends Constraint {
+    
+    public string $notUnique = 'Some batches were entered twice.';
+    
+}

src/Plugin/Validation/Constraint/BatchWorkBatchesConstraintValidator.php

@@ -0,0 +1,38 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\farm_agrikern\Plugin\Validation\Constraint;
+
+use Drupal\Core\Field\FieldItemListInterface;
+use Symfony\Component\Validator\Constraint;
+use Symfony\Component\Validator\ConstraintValidator;
+
+/**
+* Validates the BatchWorkBatches constraint.
+*/
+final class BatchWorkBatchesConstraintValidator extends ConstraintValidator {
+    
+    /**
+    * {@inheritdoc}
+    */
+    public function validate(mixed $items, Constraint $constraint): void {
+        if (!$items instanceof FieldItemListInterface) {
+            throw new \InvalidArgumentException(
+                sprintf('The validated value must be instance of \Drupal\Core\Field\FieldItemListInterface, %s was given.', get_debug_type($items))
+            );
+        }
+        $seen_batches = [];
+        foreach ($items as $delta => $item) {
+            $batch_usage = \Drupal::entityTypeManager()->getStorage('asset')->load($item->target_id);
+            $batch_id = $batch_usage->batch_field->target_id;
+            if (isset($seen_batches[$batch_id])) {
+                $this->context->buildViolation($constraint->notUnique)
+                ->atPath($delta)
+                ->addViolation();
+            }
+            $seen_batches[$batch_id] = true;
+        }
+    }
+    
+}