With Joomla! 3.0x track at end of life since last year, we find ourselves doing a lot more upgrades to Joomla! 4.0. Some of them are easy to accomplish, while others have certain customizations or components that are no longer in use with Joomla! 4.0 and need to be removed or replaced.
Joomla! is an open-source content management system (CMS) for publishing web content. As with any software, it is important to regularly update to the latest version for better features, enhanced security, and improved performance. However, migration from Joomla! 3 to Joomla! 4 may not always be smooth, and you may encounter some post-upgrade errors. This article will guide you through the most common issues and provide solutions to help you troubleshoot effectively.
Prerequisites
Before troubleshooting post-upgrade errors, always ensure you have a backup of your website. This allows you to revert back to the previous version in case the issues can’t be solved immediately. It’s also a good practice to conduct the migration in a testing environment before performing it on the live website.
1. Extension Compatibility Issues
Issue:
One of the most common issues after upgrading to Joomla! 4 is the incompatibility of extensions. If the extensions you have been using in Joomla! 3 are not compatible with Joomla! 4, they might cause errors.
Solution:
You should check each extension’s compatibility with Joomla! 4. Many extension developers provide a Joomla! 4 compatible version. Download and install these versions to fix any incompatibility issues. For extensions that do not have a Joomla! 4 version, consider looking for alternatives or contact the developer to inquire about future compatibility.
2. Template Compatibility Issues
Issue:
Another common problem is the incompatibility of Joomla! 3 templates with Joomla! 4. After the upgrade, your website might not look as expected due to these template issues.
Solution:
Just like extensions, you should check if your templates are compatible with Joomla! 4. Many template developers provide updates for Joomla! 4 compatibility. If your templates are not compatible, you may need to find replacements or hire a developer to upgrade them for you.
3. Deprecated Function Errors
Issue:
After the upgrade, you might see errors about deprecated functions in Joomla! 4. These are functions that were available in Joomla! 3 but are no longer supported in Joomla! 4.
Solution:
These errors usually come from extensions or templates using these deprecated functions. The solution is to replace these functions with their new counterparts in Joomla! 4. You might need to contact the extension or template developer for help or hire a developer if you don’t have the technical skills to do so.
Here are some of the top Joomla! 4 deprecated errors or issues we see during upgrades:
When Joomla! 4 was released, several functions that were commonly used in Joomla! 3.x became deprecated. Deprecated functions are those that the development team plans to remove in a future release and are therefore not recommended for use in new development work. Here is a list of some of the significant deprecated functions in Joomla! 4:
JFactory Class
In Joomla! 3, the JFactory class was often used to get application and other global objects. In Joomla! 4, the use of this class is deprecated. The following are some key JFactory methods that are deprecated:
JFactory::getApplication(): Deprecated in favor ofJoomlaCMSFactory::getApplication().JFactory::getUser(): Deprecated in favor ofJoomlaCMSFactory::getUser().JFactory::getDbo(): Deprecated in favor ofJoomlaCMSFactory::getDbo().JFactory::getDate(): Deprecated in favor ofJoomlaCMSFactory::getDate().JFactory::getLanguage(): Deprecated in favor ofJoomlaCMSFactory::getLanguage().
JRequest Class
The JRequest class, which was used for handling variables from the request (both GET and POST) and handling global variables, is deprecated in Joomla! 4. It is replaced by JoomlaInputInput class.
JError Class
The JError class, which was used for error handling in Joomla! 3.x, is deprecated in Joomla! 4. Instead, Joomla! 4 is promoting the use of PHP exceptions for error handling.
JUri::base() and JUri::root()
In Joomla! 3.x, the JUri::base() and JUri::root() functions were used to get the base and root URLs of the Joomla! installation. These methods are deprecated in Joomla! 4 and are replaced by JoomlaCMSUriUri::base() and JoomlaCMSUriUri::root() respectively.
JTable Class
The JTable class in Joomla! 3.x provided functions for CRUD (Create, Read, Update, Delete) operations for database tables. This class is deprecated in Joomla! 4. Instead, developers are recommended to use the JoomlaDatabaseTable class.
JModelLegacy, JViewLegacy, and JControllerLegacy classes
In Joomla! 3.x, developers could extend their model, view, and controller classes from JModelLegacy, JViewLegacy, and JControllerLegacy respectively. These legacy classes are deprecated in Joomla! 4. Instead, developers are recommended to extend their model, view, and controller classes from JoomlaCMSMVCModelBaseModel, JoomlaCMSMVCViewHtmlView, and JoomlaCMSMVCControllerBaseController respectively.
Please remember that it’s always advisable to replace these deprecated functions in your Joomla! extensions to ensure they continue to function properly in Joomla! 4 and subsequent versions. Filling up your web host’s error logs is not polite.
4. Database Errors
Issue:
Database errors can also occur after the upgrade. These errors can be due to various reasons such as issues in the upgrade process, incorrect database credentials, or incompatible database versions.
Solution:
Firstly, ensure that your database credentials in the configuration.php file are correct. If the issue persists, check if your database version is compatible with Joomla! 4. The minimum required version for Joomla! 4 is MySQL 5.6 or PostgreSQL 11.0. If your database version is lower, you will need to upgrade it.
5. PHP Version Compatibility Issues
Issue:
Joomla! 4 requires a minimum PHP version of 7.2.5. If your server is running a lower PHP version, you might encounter errors after the upgrade.
Solution:
You can check your PHP version by logging into your hosting control panel. If it is lower than 7.2.5, you should upgrade it. Most hosting providers provide an option to change the PHP version. If not, you may need to contact your hosting provider for help.
6. SEO and URL Rewriting Issues
Issue:
After migrating to Joomla! 4, you may notice that the URLs of your website have changed, causing 404 errors and impacting SEO.
Solution:
To fix this, ensure that the “URL Rewriting” option is enabled in the Joomla! global configuration. Also, check that the “htaccess.txt” file has been renamed to “.htaccess” in the root directory.
Conclusion
While upgrading from Joomla! 3 to Joomla! 4, it’s common to face some issues due to incompatibility of extensions, templates, PHP and database versions, deprecated functions, and changes in URLs. However, most of these issues can be resolved by checking compatibility, updating the necessary elements, and ensuring the right settings are in place. Always remember, backups and testing are essential before any major upgrade.
If you would like help or assistance with Joomla upgrades, migrations or support please do not hesitate to contact us.
