Moodle 3.x Developer's Guide

File Storage API

A detailed guide on the use of the File Storage API in a Moodle form is provided in the documentation at ;https://docs.moodle.org/dev/Using_the_File_API_in_Moodle_forms. Essentially, any file (and in our case this will be an image) a user adds to the editor is given a unique identifier and then stored as a draft file in the file storage area--which bit of the storage area depends on the component type.

This process is handled in the call to data_preprocessing() as follows:

function data_preprocessing(&$default_values){       global $DB;       if (!empty($this->_instance) && ($options = $DB-         >get_records_menu('choice_options',array('choiceid'=>$this-         >_instance), 'id', 'id,text'))  && ($options2 = $DB->get_records_menu('choice_options', ...