Message API
TODO: delete https://docs.moodle.org/dev/Messaging, this document replaces it.
What is this thing?
This document describes how to make use of the Moodle messaging API to send message to Moodle users.
If you are after a general introduction on using the Moodle messaging system go to https://docs.moodle.org/en/Messaging
If you are looking for implementation details of the messaging system's internal structure go to https://docs.moodle.org/dev/Messaging_2.0
If you are looking for instructions on the implementation of a custom message processor go to https://github.com/andyjdavis/moodle-custom-message-processor
If you are looking for instructions on sending messages programatically within Moodle then read on...
Overview
Moodle components have the ability to send message to users via the Moodle messaging system. Any type of component, for example a plugin or block, can register as a message producer.
File locations
The Message API is all in lib/messagelib.php and is automatically included for you during the page setup.
Functions
message_send() is the primary point of contact for the message API. Call it to send a message to a user. You can find a full description of the arguments that must be supplied at (link to phpdocs)