Update has its own controller class

application/controllers/Update.php

@@ -0,0 +1,67 @@
+<?php defined('BASEPATH') or exit('No direct script access allowed');
+
+/* ----------------------------------------------------------------------------
+ * Easy!Appointments - Open Source Web Scheduler
+ *
+ * @package     EasyAppointments
+ * @author      A.Tselegidis <alextselegidis@gmail.com>
+ * @copyright   Copyright (c) 2013 - 2020, Alex Tselegidis
+ * @license     https://opensource.org/licenses/GPL-3.0 - GPLv3
+ * @link        https://easyappointments.org
+ * @since       v1.1.0
+ * ---------------------------------------------------------------------------- */
+
+/**
+ * Update controller.
+ *
+ * Handles the update related operations.
+ *
+ * @package Controllers
+ */
+class Update extends EA_Controller {
+    /**
+     * Update constructor.
+     */
+    public function __construct()
+    {
+        parent::__construct();
+        
+        $this->load->model('admins_model');
+        $this->load->model('settings_model');
+        $this->load->model('services_model');
+        $this->load->model('providers_model');
+        $this->load->model('customers_model');
+        
+        $this->load->library('instance');
+    }
+
+    /**
+     * This method will update the instance to the latest available version in the server.
+     *
+     * IMPORTANT: The code files must exist in the server, this method will not fetch any new files but will update
+     * the database schema.
+     *
+     * This method can be used either by loading the page in the browser or by an ajax request. But it will answer with
+     * JSON encoded data.
+     */
+    public function index()
+    {
+        try
+        {
+            if (cannot('edit', PRIV_SYSTEM_SETTINGS))
+            {
+                show_error('Forbidden', 403);
+            }
+
+            $this->instance->migrate();
+
+            $view = ['success' => TRUE];
+        }
+        catch (Throwable $e)
+        {
+            $view = ['success' => FALSE, 'exception' => $e->getMessage()];
+        }
+
+        $this->load->view('pages/update', $view);
+    }
+}