1Do I need to update to Joomla! 3.0?
NO. Recently Joomla! has adopted the Ubuntu release cycle. What that means?
Long Term Support (LTS). This versions have a support lifetime of approximately 24 months. The Joomla! default update cycle.
Standard Term Support (STS). This versions have a support lifetime of approximately 6 months. We can call it the fast update cycle.
Do I really want to base my website in something that has six months of support?
The Joomla! 3.0 FAQ may help you to decide. 90% of the times the answer should be NO. Our advice: If you aren't able to fix it don't break it.
Take us as an example. Why we switched to Joomla! 3.0?
We are a web development company and we are supposed to live on the cuting edge. Our Joomla! extensions have to work in both 2.5 and 3.0 versions and the best way to achieve this is working with them daily in the desired enviroments. If something goes wrong after the update we can fix it ourselves.
So you decided that you are ready to switch to Joomla! 3.0? That doesn't mean that Joomla! 3.0 is ready for you. The first step is checking if your hosting provider meets the requirements.
Personally I wouldn't still use PostgreSQL or MSSQL as database servers. They are having some issues and this is the first release that supports them.
After updating we will ensure that our database is Ok with the great checkin tool integrated in Joomla! 2.5. Go to System > Maintenance > Global Check-in select all the tables and click checkin.
Need to mention that first of all you need to fully backup your site? And now updated and checked is the best moment. You can use Akeeba Backup. A great extensions that is already compatible with Joomla! 3.0.
If you use a version control system you can create a new branch. That way you can allways come back to the production branch if something goes wrong while updating.
The first thing to think in: your template. If it isn't compatible with Joomla! 3.0 you may have to change it. If you finally have to change it why don't use a responsive one? Almost all the template clubs out there are exclusively releasing responsive templates.
Related to templates there is another important check: Your template overrides. They may be outdated and use some of the deprecated functions. As an example in our case our content category overrides used "JHtml::core();" and we had to replace it with "JHtml::_('behavior.framework');".
Another important dependency will be the main content management of our site. You can use native Joomla! or K2 content that has already been updated to work with J!3.0.
The next step is to check that all the extensions that you need are available for Joomla! 3.0. You can use the advanced search in the Joomla Extensions Directory (JED).
Actually there are only 485 extensions (from more than 10.000) marked as compatible for Joomla! 3.0. This may give you an idea of the current Joomla! 3.0 limits.
If you find that your extensions are not compatible you can search alternatives. If you don't find alternatives you can ask the developer if he has planned making the extensions compatible. Maybe it's worth waiting 1 or 2 weeks.
Our advice is that before upgrading you remove all the extensions installed that are not compatible with Joomla! 3.0.
This is a really important step as your site will be broken if you don't remove an extension that isn't compatible.
One of the biggest backward incompatibilities in Joomla! 3.0 is the deprecation of the DS constant. A lot of extensions still require it and it's a good idea to keep/reintroduce it while all the extensions are migrated.
In our first migration attempt we manually reintroduced it. Brian Teeman suggested us to create a system plugin to avoid this simple step to the end users. And we did it. So the next recommended step is to download, install and enable it (do not forget to enable it! ).
Cross your fingers and click on the "Install the update" button.
If your issue is related with the frontend template you can assign the default Protostar template while you try to fix it.
Feel free to ask us any question or problem related with the upgrade to fix/keep updated this guide.