table.php

<?php
/*
 * Plugin Name: Ready to Publish
 * Description: Add a little checkbox to ensure that you are ready to publish a post.
 * Author:      Jake Spurlock
 * Version:     0.5.0
*/

class Ready_to_Publish {
	/**
	 * The one instance of Ready_to_Publish.
	 *
	 * @var Ready_to_Publish
	 */
	private static $instance;

	/**
	 * Instantiate or return the one Ready_to_Publish instance.
	 *
	 * @return Ready_to_Publish
	 */
	public static function instance() {
		if ( is_null( self::$instance ) ) {
			self::$instance = new self();
		}

		return self::$instance;
	}

	/**
	 * Initiate actions.
	 *
	 * @return Ready_to_Publish
	 */
	public function __construct() {
		add_action( 'admin_enqueue_scripts', array( $this,  'enqueueueue_js' ) );
		add_shortcode( 'table', array( $this, 'table' ) );

	}

	/**
	 * Enqueue the Javascript
	 * @return void
	 */
	public function enqueueueue_js() {
		global $post;
		if ( has_shortcode( $post->post_content, 'table' ) ) {
			wp_enqueue_script( $this->slug, plugin_dir_url( __FILE__ ) . 'ready-to-publish.js', array( 'jquery' ) );
		}

	}

	/**
	 * Add a checkbox to post_submitbox_misc_actions area that must be checked ahead of publishing a post.
	 * @return void
	 */
	public function table( $atts, $content ) {
		return esc_url( $atts['url'] );
	}

}

/**
 * Instantiate or return the one Ready_to_Publish instance.
 *
 * @return Ready_to_Publish
 */
function ready_to_publish_instance() {
	return Ready_to_Publish::instance();
}

// Kick off the plugin on init
add_action( 'init', 'ready_to_publish_instance' );