A slightly more complicated test involves seeing whether or not another plugin is installed. This can be useful if you have one plugin that depends on another, or perhaps you just need to test whether or not a site has all of the plugins you expect it to. We took this a step further. The following function lets you specify the required plugins and the required versions of those plugins:
/** * This relies on the output of WP's get_plugins() and * get_option('active_plugins') functions. * * @param array $required_plugins An associative array with * the names of the plugins and the required versions, e.g. * array( 'My Great Plugin' => '0.9', 'Some Other Plugin' => '1.0.1' ) * @return none An error message is registered in self::$errors if the * test fails. There are 2 errors that can be generated: one if the * plugin's version is too old, and another if it is missing altogether. */ public static function wp_required_plugins($required_plugins...