The move to namespaces is one of the biggest changes in Joomla 4. We converted every core extension to namespaces and touched every library file. But we have a BC promise. The target is that an extension developer can keep the same code base for J3 and J4, running it on both systems. How all of that works and what it means for you as extension developer will be illustrated in this workshop.

The workshop is divided into two parts. First I will give a theoretical introduction about the changes we as extension developer are facing and some important backwards compatibility breaks. I will explain our libraries backport and legacy forward approach, keeping full backwards compatibility. Also what for changes we can except till the final version does come out.

In the second part we will together convert your extensions step by step. We will dive into the new aspects of component loading, namespaces and extension structure. You will have to make your hands dirty with your extension on Joomla 4.

The goal of the workshop is that you leave the room with a converted Joomla 4 extension.

Attendee Requirements:

You have to bring your own laptop with your development environment of your Joomla extension. Preferable you have installed your extension already on Joomla and made it run by removing the deprecated code usage which got removed in Joomla 4. It will save us valuable time.

Trainer Profile:

Allon Moritz published in 2007 his first Joomla extension in the JED. It began as hobby in an old farmhouse together with friends. In 2015 he did found the Digital Peak GmbH company (, which specializes in Joomla extension development. Allon Moritz, aka laoneo, is involved in different teams and helps actively on the development of the Joomla CMS at Github.

For example the custom fields functionality is done by him. Currently he is a member of the "Production Department", leads the media manager team and is porting the Joomla CMS to namespaces in the Joomla 4 working group.