Check if a Plugin is Active (or Network Active on a network)

<?php
/**
 * Checks to see if an asset is activated or not.
 *
 * @param string $path Path to the asset (e.g., akismet/akismet.php).
 *
 * @return bool true if activated, false if not.
 */
function dlx_is_plugin_activated( $path ) {
	if ( ! function_exists( 'is_plugin_active_for_network' ) ) {
		require_once ABSPATH . '/wp-admin/includes/plugin.php';
	}

	if ( is_multisite() ) {
		if ( is_plugin_active_for_network( $path ) ) {
			return true;
		}
	}
	if ( is_plugin_active( $path ) ) {
		return true;
	}
	return false;
}