functions.php

<?php
/**
 * Write a log entry.
 *
 * Helper function to write a log entry with a given title, category, and any
 * log data. Relies on the Maintenance Functionality mu-plugin being present.
 *
 * Usage:
 *
 *     kanuka_log( 'Data Import', 'import', array(
 *         'status' => 'success',
 *         'data'   => $data,
 *     ) );
 *
 * @param string $title The title of the log entry.
 * @param string|null $category The category of the log entry (optional).
 * @param mixed|null $data The log data to be saved (optional).
 */
function kanuka_log( $title, $category = null, $data = null ) {

	// Bail if our mu-plugin isn't present.
	if ( ! class_exists( 'Kanuka_Maintenance_Functionality' ) ) {
		return;
	}

	Kanuka_Maintenance_Functionality::log( $title, $category, $data );
}