pre_get_main_site_id │ filter-hook │ WP 4.9.0

Filters the main site ID.

Returning a positive integer will effectively short-circuit the function.

Usage

add_filter( 'pre_get_main_site_id', 'wp_kama_pre_get_main_site_id_filter', 10, 2 );

/**
 * Function for `pre_get_main_site_id` filter-hook.
 * 
 * @param int|null   $main_site_id If a positive integer is returned, it is interpreted as the main site ID.
 * @param WP_Network $network      The network object for which the main site was detected.
 *
 * @return int|null
 */
function wp_kama_pre_get_main_site_id_filter( $main_site_id, $network ){

	// filter...
	return $main_site_id;
}

$main_site_id(int|null)

If a positive integer is returned, it is interpreted as the main site ID.

$network(WP_Network)

The network object for which the main site was detected.

Changelog

Where the hook is called

$main_site_id = (int) apply_filters( 'pre_get_main_site_id', null, $this );

Where the hook is used in WordPress