Added common response/error objects for inner communication between backend clients and their sub actions.

src/Backends/Common/Response.php

@@ -0,0 +1,48 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Backends\Common;
+
+final class Response
+{
+    /**
+     * Wrap Clients responses into easy to consume object.
+     *
+     * @param bool $status Whether the operation is Successful.
+     * @param mixed $response the actual response.
+     * @param Error|null $error If the response has an error, populate it using {@see Error} object.
+     * @param mixed $extra an array that can contain anything.
+     */
+    public function __construct(
+        public readonly bool $status,
+        public readonly mixed $response = null,
+        public readonly Error|null $error = null,
+        public readonly array $extra = [],
+    ) {
+    }
+
+    /**
+     * Does the response contain an error object?
+     */
+    public function hasError(): bool
+    {
+        return null !== $this->error;
+    }
+
+    /**
+     * Return Error response.
+     */
+    public function getError(): Error
+    {
+        return $this->error ?? new Error('No error logged.');
+    }
+
+    /**
+     * Is the Operation Successful?
+     */
+    public function isSuccessful(): bool
+    {
+        return $this->status;
+    }
+}