add nova

nova/src/Fields/DetachesPivotModels.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace Laravel\Nova\Fields;
+
+use Laravel\Nova\Contracts\Deletable;
+use Laravel\Nova\DeleteField;
+use Laravel\Nova\Nova;
+
+trait DetachesPivotModels
+{
+    /**
+     * Get the pivot record detachment callback for the field.
+     *
+     * @return \Closure(\Laravel\Nova\Http\Requests\NovaRequest, mixed):bool
+     */
+    protected function detachmentCallback()
+    {
+        return function ($request, $model) {
+            $pivotAccessor = $model->{$this->attribute}()->getPivotAccessor();
+
+            foreach ($model->{$this->attribute}()->withoutGlobalScopes()->cursor() as $related) {
+                $resource = Nova::newResourceFromModel($related);
+
+                $pivot = $related->{$pivotAccessor};
+
+                $pivotFields = $resource->resolvePivotFields($request, $request->resource);
+
+                $pivotFields->whereInstanceOf(Deletable::class)
+                        ->filter->isPrunable()
+                        ->each(function ($field) use ($request, $pivot) {
+                            /** @var \Laravel\Nova\Fields\Field&\Laravel\Nova\Contracts\Deletable $field */
+                            DeleteField::forRequest($request, $field, $pivot)->save();
+                        });
+
+                $pivot->delete();
+            }
+
+            return true;
+        };
+    }
+}