[SonataExtraBundle] Show prevent delete support no stringnable

packages/sonata-extra-bundle/Resources/views/CRUD/show_prevent_delete.html.twig

@@ -9,7 +9,7 @@
     <table class="table table-bordered table-striped table-hover sonata-ba-list">
         {% for related_entity in related_entities %}
             <tr>
-                <td>{{ related_entity }}</td>
+                <td>{{ related_entity|entity_to_string }}</td>
                 {% if related_admin %}
                     <td>
                         <div class="btn-group">

packages/sonata-extra-bundle/Twig/EntityTwigExtension.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace Draw\Bundle\SonataExtraBundle\Twig;
+
+use Doctrine\Common\Util\ClassUtils;
+use Twig\Extension\AbstractExtension;
+use Twig\TwigFilter;
+
+class EntityTwigExtension extends AbstractExtension
+{
+    public function getFilters(): array
+    {
+        return [
+            new TwigFilter('entity_to_string', [$this, 'entityToString']),
+        ];
+    }
+
+    public function entityToString($entity): string
+    {
+        if (method_exists($entity, '__toString')) {
+            return (string) $entity;
+        }
+
+        return sprintf('%s:%s', ClassUtils::getClass($entity), spl_object_hash($entity));
+    }
+}