Check If Required Plugin Is Active

It might be, that your own written Plugin requires another stand alone Plugin to be active. For example if you like to offer a version with enhanced functionality of a Plugin. There are certainly a variety of usage and the implementation is not difficult.

For the implementation, we need the active Plugins, which are found in the database, table options, the active_plugins. Afterwards, I will simply look in the array, which contains the active Plugins, whether the required plugin included and active or not:

$plugins = get_option('active_plugins');
$required_plugin = 'debug_queries/debug_queries.php';
$debug_queries_on = FALSE;
if ( in_array( $required_plugin , $plugins ) ) {
	$debug_queries_on = TRUE; // Example for yes, it's active
}