Photon Template Library
Photon is a PHP library built by Jadu to power templates for Jadu Central.
Themes are implemented as Symfony bundles and registered with Jadu Central by running a terminal command.
Templates are extensible and can be overridden easily. In common with many Symfony applications, routes are defined in the configuration file routes.yml, controller dependencies are set in the configuration file services.yml.
Photon is built upon the Symfony framework, so having a good knowledge of the framework and Twig template language is beneficial.
The following guides from the Symfony documentation are a good starting point: