customize_preview_init example

        do_action( 'customize_register', $this );

        if ( $this->settings_previewed() ) {
            foreach ( $this->settings as $setting ) {
                $setting->preview();
            }
        }

        if ( $this->is_preview() && ! is_admin() ) {
            $this->customize_preview_init();
        }
    }

    /** * Prevents Ajax requests from following redirects when previewing a theme * by issuing a 200 response instead of a 30x. * * Instead, the JS will sniff out the location header. * * @since 3.4.0 * @deprecated 4.7.0 * * @param int $status Status. * @return int */