Merge pull request #7186 from kenjis/fix-docs-upgrade_4xx-BASEPATH

docs: improve Upgrading from 3.x to 4.x

Author: kenjis

user_guide_src/source/installation/upgrade_4xx.rst

@@ -49,6 +49,9 @@ Application Structure
 - The **application** folder is renamed as **app** and the framework still has **system** folders,
   with the same interpretation as before.
 - The framework now provides for a **public** folder, intended as the document root for your app.
+- The ``defined('BASEPATH') OR exit('No direct script access allowed');`` line is not necessary
+  because files outside the **public** folder are not accessible in the standard configuration.
+  And CI4 no longer defines the constant ``BASEPATH``, so remove the line in all files.
 - There is also a **writable** folder, to hold cache data, logs, and session data.
 - The **app** folder looks very similar to **application** for CI3, with some
   name changes, and some subfolders moved to the **writable** folder.
@@ -132,8 +135,8 @@ Helpers
     - `redirect() Documentation CodeIgniter 3.X <https://codeigniter.com/userguide3/helpers/url_helper.html#redirect>`_
     - `redirect() Documentation CodeIgniter 4.X <../general/common_functions.html#redirect>`_
 
-Events
-======
+Hooks
+=====
 
 - `Hooks <https://www.codeigniter.com/userguide3/general/hooks.html>`_ have been
   replaced by :doc:`../extending/events`.

user_guide_src/source/installation/upgrade_controllers.rst

@@ -27,6 +27,7 @@ Upgrade Guide
 1. First, move all controller files to the folder **app/Controllers**.
 2. Add this line just after the opening php tag: ``namespace App\Controllers;``
 3. Replace ``extends CI_Controller`` with ``extends BaseController``.
+4. Remove the line ``defined('BASEPATH') OR exit('No direct script access allowed');`` if it exists.
 
 | If you use sub-directories in your controller structure, you have to change the namespace according to that.
 | For example, you have a version 3 controller located in **application/controllers/users/auth/Register.php**,

user_guide_src/source/installation/upgrade_migrations.rst

@@ -26,7 +26,7 @@ Upgrade Guide
 
 1. If your v3 project uses sequential migration names you have to change those to timestamp names.
 2. You have to move all migration files to the new folder **app/Database/Migrations**.
-3. Remove the following line ``defined('BASEPATH') OR exit('No direct script access allowed');``.
+3. Remove the line ``defined('BASEPATH') OR exit('No direct script access allowed');`` if it exists.
 4. Add this line just after the opening php tag: ``namespace App\Database\Migrations;``.
 5. Below the ``namespace App\Database\Migrations;`` line add this line: ``use CodeIgniter\Database\Migration;``
 6. Replace ``extends CI_Migration`` with ``extends Migration``.

user_guide_src/source/installation/upgrade_views.rst

@@ -28,6 +28,7 @@ Upgrade Guide
     - from ``$this->load->view('directory_name/file_name')`` to ``return view('directory_name/file_name');``
     - from ``$content = $this->load->view('file', $data, TRUE);`` to ``$content = view('file', $data);``
 3. (optional) You can change the echo syntax in views from ``<?php echo $title; ?>`` to ``<?= $title ?>``
+4. Remove the line ``defined('BASEPATH') OR exit('No direct script access allowed');`` if it exists.
 
 Code Example
 ============