XML-RPC is a way in which systems can call procedures on remote systems through HTTP using XML to encode data. Joomla! includes an XML-RPC server that we can extend using plugins. For more information about plugins, please refer to Chapter 7, Plugin Design.
The XML-RPC server will only function if the 'Enable Web Services' option in the Global Configuration is enabled.
Before we begin, it is important to understand that Joomla! relies heavily on the
phpxmlrpc library, which is available from: http://phpxmlrpc.sourceforge.net. Due to this, some of the conventions we will encounter when building XML-RPC plugins will differ from the rest of Joomla!.
When we briefly discussed XML-RPC in Chapter 7, Plugin Design ...