start.php

<?php

define('COMMENT_TRACKER_RELATIONSHIP', 'comment_subscribe');
define('COMMENT_TRACKER_UNSUBSCRIBE_RELATIONSHIP', 'comment_tracker_unsubscribed');

require_once __DIR__ . '/lib/hooks.php';
require_once __DIR__ . '/lib/events.php';
require_once __DIR__ . '/lib/functions.php';

/**
 * Initialise the plugin
 */
function comment_tracker_init() {

	$settings = elgg_get_plugin_from_id('comment_tracker')->getAllSettings();
	if (empty($settings['show_entity_button'])) {
		$settings['show_entity_button'] = 'yes';
	}
	if (empty($settings['show_river_button'])) {
		$settings['show_river_button'] = 'no';
	}

	if (elgg_is_logged_in()) {
		elgg_extend_view('page/elements/comments', "comment_tracker/manage_subscription", 400);
		elgg_extend_view('discussion/replies', "comment_tracker/manage_subscription", 400);
	}

	// Extend views
	elgg_extend_view('elgg.css', 'css/comment_tracker.css');
	elgg_extend_view('notifications/subscriptions/forminternals', 'comment_tracker/settings');

	elgg_require_js('comment_tracker/subscribe');

	// Register actions
	elgg_register_action("comment_tracker/subscribe", elgg_get_plugins_path() . "comment_tracker/actions/subscribe.php");

	// plugin hooks
	// save our settings
	elgg_register_plugin_hook_handler('action', 'notificationsettings/save', 'comment_tracker_savesettings');

	// add our subscription links
	if ($settings['show_entity_button'] === 'yes') {
		elgg_register_plugin_hook_handler('register', 'menu:entity', 'comment_tracker_register_menus');
	}
	if ($settings['show_river_button'] === 'yes') {
		elgg_register_plugin_hook_handler('register', 'menu:river', 'comment_tracker_register_menus');
	}
	
	if ($settings['notify_owner'] == 'yes') {
		// overwrite comment/save action to remove hard-coded owner notification
		elgg_register_action("comment/save", elgg_get_plugins_path() . "comment_tracker/actions/comment/save.php");
	}

	// prepare the notification message
	elgg_register_plugin_hook_handler('prepare', 'notification:create:object:comment', 'comment_tracker_prepare_notification');
	// get subscriptions for a commented entity
	elgg_register_plugin_hook_handler('get', 'subscriptions', 'comment_tracker_get_subscriptions');

	// Set core notifications system to track the creation of new comments
	elgg_register_notification_event('object', 'comment', array('create'));

	// register events
	elgg_register_event_handler('create', 'object', 'comment_tracker_subscribe_owner_automatically');
	elgg_register_event_handler('create', 'object', 'comment_tracker_autosubscribe');

	// set up our pages
	elgg_register_page_handler('comment_tracker', 'comment_tracker_page_handler');

	// fix typo in settings (from 1.7 version)
	run_function_once('comment_tracker_update_20121025a');
}

/**
 * Handle calls to /comment_tracker
 *
 * @param $array $pages URL segments
 */
function comment_tracker_page_handler($page) {
	gatekeeper();
	$user = get_user_by_username($page[1]);

	if (!$user || !$user->canEdit()) {
		return false;
	}

	elgg_set_context('settings');

	$content = "<p>" . elgg_echo('comment:notification:settings:description') . "</p>";

	// display subscribed items
	$content .= elgg_list_entities_from_relationship(array(
		'type' => 'object',
		'subtypes' => comment_tracker_get_entity_subtypes(),
		'relationship_guid' => $user->guid,
		'relationship' => COMMENT_TRACKER_RELATIONSHIP,
		'full_view' => false,
		'order_by' => 'r.time_created DESC'
	));

	if (!$content) {
		$content = elgg_echo('comment:subscriptions:none');
	}

	elgg_push_breadcrumb(elgg_echo('settings'), 'settings/user/' . $user->username);
	elgg_push_breadcrumb(elgg_echo('notifications'), 'notifications/personal/' . $user->username);
	elgg_push_breadcrumb(elgg_echo('comment:subscriptions'));

	$title = elgg_echo('comment:subscriptions');

	$body = elgg_view_layout('content', array(
		'title' => $title,
		'content' => $content,
		'filter' => false
	));

	echo elgg_view_page($title, $body);
}

// Register event handlers
elgg_register_event_handler('init', 'system', 'comment_tracker_init');