llgruff

<?php
/**
 * Detect if a WordPress plugin is active
 * A function you can use to check if plugin is active/loaded for your plugins/themes
 * @link //gist.github.com/llgruff/c5666bfeded5de69b1aa424aa80cc14f
 */

// When coding plugins that rely on another one, like Private Content for bbPress or Visual Attributes for WooCommerce, you need to make if the WordPress Plugin is active to initialize your plugin routines or display a notice saying that the required plugin must be activated. In this tutorial we’ll see how to detect whether a certain plugin is active in a couple of ways.

## 1. Check whether a certain class or function or constant exists