[WordPress] Including Ajax files in WordPress so the code fires early enough to be used for the rest of the plugin.

00-include-ajax-specific-files.php

<?php

require dirname( __FILE__ ) . '/inc/sensei-ajax.php';
/**
 * All Ajax functionality. This is included in a single file
 * so that the events can be registered earlier in the WordPress lifeycle.
 *
 * @since    1.0.0
 */
function sensei_start_ajax() {

	$ajax = new Sensei_Ajax();
	$ajax->init();

}
sensei_start_ajax();

01-start-the-plugin.php

<?php

require_once dirname( __FILE__ ) . '/lib/sensei-timed-quizzes/sensei-timed-quizzes.php';
/**
 * Begins execution of the Timed Quiz plugin.
 *
 * Since everything within the plugin is registered via hooks,
 * then kicking off the plugin from this point in the file does
 * not affect the page life cycle.
 *
 * @since    1.0.0
 */
function sensei_timed_quizzes_start() {

	$plugin = new Sensei_Timed_Quizzes();
	$plugin->run();

}
sensei_timed_quizzes_start();