Wordpress addon sample code.

scripts.js

_

styles.css

_

wp_addon.php

<?php defined('ABSPATH') or die("No script kiddies please!");

class WP_Addon
{
	public function __construct()
	{
		add_shortcode('WP_Addon_shortcode', array($this, 'add_shortcode'));

		add_action('wp_head', array($this, 'wp_head'));
		add_action('wp_footer', array($this, 'wp_footer'));
		add_action('wp_enqueue_scripts', array($this, 'wp_enqueue_scripts'));
	}

	public function wp_enqueue_scripts()
	{
		wp_enqueue_style('WP_Addon', $this->get_file_url('styles.css'), array(), filemtime(dirname(__FILE__) .'/styles.css'));
		wp_enqueue_script('WP_Addon', $this->get_file_url('scripts.js'), array(), filemtime(dirname(__FILE__) .'/scripts.js'), true);
	}

	public function add_shortcode($atts, $content)
	{
		$atts = shortcode_atts(array(
			'param1' => 'default value',
		), $atts);



		return $content;
	}

	public function wp_head()
	{
		
	}

	public function wp_footer()
	{
		
	}

	###############################################
	# UTILS
	###############################################

	private function get_file_url($file_name)
	{
	    $file_path = dirname(__FILE__) . '/' . $file_name;

	    return str_replace(get_template_directory(), get_template_directory_uri(), $file_path);
	}
}

new WP_Addon;