I decided to install Joomla 5.0.
- backing up the site and the database:
see Site Backup - Verification of all extensions and plugins: compatibility with the v5.x
- disable non-compatible plugins/extensions, e.g.:
We can help each other myqsl and directly disable extensions
- UPDATE `jom50_extensions` SET `enabled` = '0' WHERE `jom50_extensions`.`name` LIKE '%jcomments%';
- UPDATE `jom50_extensions` SET `enabled` = '0' WHERE `jom50_extensions`.`name` LIKE '%attach%';
- UPDATE `jom50_extensions` SET `enabled` = '0' WHERE `jom50_extensions`.`name` LIKE '%iyosis%';
- ...
- UPDATE `jom50_extensions` SET `enabled` = '0' WHERE `jom50_extensions`.`name` LIKE '%kunena%';
- UPDATE `jom50_extensions` SET `enabled` = '0' WHERE `jom50_extensions`.`name` LIKE '%cloud%';
- UPDATE `jom50_extensions` SET `enabled` = '0' WHERE `jom50_extensions`.`name` LIKE '%JEV%';
- copying the old directory to a new directory, and duplicating the database.
at OVH I have several databases. I saved the database, renamed the tables with a prefix jom50_ and recreated the database jooma_5.
- Updating extensions
- it is necessary to add aliases for all Joomla classes in third-party plugins and components
cf Renommage des classes Jxxx (à partir de J3.8)
| JAccessRules | Joomla\CMS\Access\Rules | use Joomla\CMS\Access\Rules as JAccessRules; |
| JApplicationHelper | Joomla\CMS\Application\ApplicationHelper | use Joomla\CMS\Application\ApplicationHelper as JApplicationHelper; |
example on a php file:
- use Joomla\CMS\MVC\Controller\AdminController as JControllerAdmin;
- use Joomla\CMS\MVC\Controller\BaseController as JControllerLegacy;
- use Joomla\CMS\Factory as JFactory
- It is also possible while waiting to make any changes (add all aliases in plugins and components) to activate the plugin
On this occasion I updated the Xmap component with the joomla 5.0 APIs 
JLTRY/Xmap/releases/tag/V4.0