Dependent Plugin Activation/Deactivation and Alert

plugin.php

<?php 
/*
 * Dependent Plugin Activation/Deactivation
 * 
 * Sources:
 * 1. https://pippinsplugins.com/checking-dependent-plugin-active/
 * 2. http://10up.com/blog/2012/wordpress-plug-in-self-deactivation/
 *
 */
 
function child_plugin_init() {
	
	// If Parent Plugin is NOT active
	if ( current_user_can( 'activate_plugins' ) && !class_exists( 'Parent Plugin Class' ) ) {
		
		add_action( 'admin_init', 'my_plugin_deactivate' );
		add_action( 'admin_notices', 'my_plugin_admin_notice' );
		
		// Deactivate the Child Plugin
		function my_plugin_deactivate() {
		  deactivate_plugins( plugin_basename( __FILE__ ) );
		}
		
		// Throw an Alert to tell the Admin why it didn't activate
		function my_plugin_admin_notice() {
		   echo "<div class=\"error\"><p><strong>" . __( '"The Child Plugin"</strong> requires "The Parent Plugin" to function correctly. Please activate "The Parent Plugin" before activating "The Child Plugin". For now, the plug-in has been <strong>deactivated</strong>.', 'textdomain' ) . "</p></div>";
		   if ( isset( $_GET['activate'] ) )
				unset( $_GET['activate'] );
		}

    } else {
		
		// include all your plugin files here
		
	}
}

add_action( 'plugins_loaded', 'child_plugin_init' );