How To Check If a WordPress Plugin is “Sitewide Active” (or “Network Active”)

I’ve just got a support question for my Countdown WordPress Plugin¬†which was written only for WooCommerce to use their internal schedule functionality. A guy complaint about a problem that the plugin always shows a warning message that tells him that WooCommerce is not installed. It turned out that he had installed my plugin on a multisite WordPress site where WooCommerce was installed site wide but my plugin was not. So the question was: How can I check if a plugin is site wide or network active? Continue reading