Fix error on delete when withFiles is enabled

src/CKEditor5Classic.php

@@ -7,6 +7,8 @@
 use NumaxLab\NovaCKEditor5Classic\Handlers\DiscardPendingAttachments;
 use NumaxLab\NovaCKEditor5Classic\Handlers\StorePendingAttachment;
 use NumaxLab\NovaCKEditor5Classic\Models\PendingAttachment;
+use NumaxLab\NovaCKEditor5Classic\Models\DeleteAttachments;
+use NumaxLab\NovaCKEditor5Classic\Models\DetachAttachment;
 
 class CKEditor5Classic extends Trix
 {
@@ -49,6 +51,8 @@ public function withFiles($disk = null)
         $this->disk($disk);
 
         $this->attach(new StorePendingAttachment($this))
+            ->detach(new DetachAttachment($this))
+            ->delete(new DeleteAttachments($this))
             ->discard(new DiscardPendingAttachments())
             ->prunable();
 

src/Models/DeleteAttachments.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace  NumaxLab\NovaCKEditor5Classic\Models;
+
+use Illuminate\Http\Request;
+
+class DeleteAttachments
+{
+    /**
+     * The field instance.
+     *
+     * @var \Laravel\Nova\Fields\Trix
+     */
+    public $field;
+
+    /**
+     * Create a new class instance.
+     *
+     * @param  \Laravel\Nova\Fields\Trix  $field
+     * @return void
+     */
+    public function __construct($field)
+    {
+        $this->field = $field;
+    }
+
+    /**
+     * Delete the attachments associated with the field.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @param  mixed  $model
+     * @return void
+     */
+    public function __invoke(Request $request, $model)
+    {
+        Attachment::where('attachable_type', get_class($model))
+                ->where('attachable_id', $model->getKey())
+                ->get()
+                ->each
+                ->purge();
+
+        return [$this->field->attribute => ''];
+    }
+}

src/Models/DetachAttachment.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace  NumaxLab\NovaCKEditor5Classic\Models;
+
+use Illuminate\Http\Request;
+
+class DetachAttachment
+{
+    /**
+     * Delete an attachment from the field.
+     *
+     * @param  \Illuminate\Http\Request  $request
+     * @return void
+     */
+    public function __invoke(Request $request)
+    {
+        Attachment::where('url', $request->attachmentUrl)
+                        ->get()
+                        ->each
+                        ->purge();
+    }
+}