Amazon_S3_And_CloudFront::maybe_disable_save_button PHP Method

    function maybe_disable_save_button($defined_settings = array())
    {
        $attr = 'disabled="disabled"';
        $defined_settings = !empty($defined_settings) ? $defined_settings : $this->get_defined_settings();
        $whitelisted_settings = $this->get_settings_whitelist();
        $settings_to_skip = array('bucket', 'region', 'permissions', 'virtual-host');
        foreach ($whitelisted_settings as $setting) {
            if (in_array($setting, $settings_to_skip)) {
                continue;
            }
            if ('object-prefix' === $setting) {
                if (isset($defined_settings['enable-object-prefix']) && '0' === $defined_settings['enable-object-prefix']) {
                    continue;
                }
            }
            if ('cloudfront' === $setting) {
                if (isset($defined_settings['domain']) && 'cloudfront' !== $defined_settings['domain']) {
                    continue;
                }
            }
            if (!isset($defined_settings[$setting])) {
                // If we're here, there's a setting that hasn't been defined.
                return '';
            }
        }
        return $attr;
    }