eXo Platform extensions are special .war files that are recognized by eXo Platform and contribute to custom configurations to the PortalContainer. To create your own site, you first need to create an extension.

The extension mechanism makes possible to extend or even override site resources in almost plug-and-play way. You simply add a .war archive with your custom resources to the war folder and edit the configuration of the PortalContainerConfig service. Customizing a site does not involve unpacking and repacking the original site .war archives. Instead, you need to create your own .war archive with your own configurations, and modify resources. The content of your custom .war archive overrides the resources in the original archives.

The most elegant way to reuse configuration for different coexisting sites is by way of extension mechanism. That is, you can inherit resources and configurations from existing web archives, then simply add extra resources and configurations to your extension, and override ones which need to be changed by including modified copies.

In this chapter, you will have opportunity to learn about eXo Platform extensions via the following topics: