event-list.php

<?php
/*
Plugin Name: Event List
Plugin URI: http://wordpress.org/extend/plugins/event-list/
Description: Manage your events and show them in a list view on your site.
Version: 0.6.9
Author: Michael Burtscher
Author URI: http://wordpress.org/extend/plugins/event-list/
License: GPLv2

A plugin for the blogging MySQL/PHP-based WordPress.
Copyright 2012-2014 Michael Burtscher

This program is free software; you can redistribute it and/or
modify it under the terms of the GNUs General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You can view a copy of the HTML version of the GNU General Public
License at http://www.gnu.org/copyleft/gpl.html
*/

if( !defined( 'ABSPATH' ) ) {
	exit;
}

// GENERAL DEFINITIONS
define( 'EL_URL', plugin_dir_url( __FILE__ ) );
define( 'EL_PATH', plugin_dir_path( __FILE__ ) );

require_once(EL_PATH.'includes/options.php');

// MAIN PLUGIN CLASS
class Event_List {
	private $shortcode;
	private $styles_loaded;

	/**
	 * Constructor:
	 * Initializes the plugin.
	 */
	public function __construct() {
		$this->shortcode = null;
		$this->styles_loaded = false;

		// ALWAYS:
		// Register shortcodes
		add_shortcode( 'event-list', array( &$this, 'shortcode_event_list' ) );
		// Register widgets
		add_action( 'widgets_init', array( &$this, 'widget_init' ) );
		// Add RSS Feed page
		$options = EL_Options::get_instance();
		if($options->get('el_enable_feed')) {
			include_once(EL_PATH.'includes/feed.php');
			$feed = EL_Feed::get_instance();
		}

		// ADMIN PAGE:
		if ( is_admin() ) {
			// Include required php-files and initialize required objects
			require_once( EL_PATH.'admin/admin.php' );
			EL_Admin::get_instance()->init_admin_page();
		}

		// FRONT PAGE:
		else {
			// Register actions
			add_action('wp_print_styles', array( &$this, 'print_styles' ) );
		}
	} // end constructor

	public function shortcode_event_list($atts) {
		if(null == $this->shortcode) {
			require_once(EL_PATH.'includes/sc_event-list.php');
			$this->shortcode = SC_Event_List::get_instance();
			if(!$this->styles_loaded) {
				// normally styles are loaded with wp_print_styles action in head
				// but if the shortcode is not in post content (e.g. included in a theme) it must be loaded here
				$this->enqueue_styles();
			}
		}
		return $this->shortcode->show_html( $atts );
	}

	public function widget_init() {
		// Widget "event-list"
		require_once( EL_PATH.'includes/widget.php' );
		return register_widget( 'EL_Widget' );
	}

	public function print_styles() {
		global $post;
		if(is_active_widget(null, null, 'event_list_widget') || (is_object($post) && strstr($post->post_content, '[event-list'))) {
			$this->enqueue_styles();
		}
	}

	public function enqueue_styles() {
		wp_register_style('event-list', EL_URL.'includes/css/event-list.css');
		wp_enqueue_style( 'event-list');
		$this->styles_loaded = true;
	}
} // end class linkview


// create a class instance
$event_list = new Event_List();
?>