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filter is not described

sites_pre_query filter-hook . WP 5.2.0

Filter the site data before the get_sites query takes place.

Return a non-null value to bypass WordPress's default site queries.

The expected return type from this filter depends on the value passed in the request query_vars: When $this->query_vars['count'] is set, the filter should return the site count as an int. When 'ids' === $this->query_vars['fields'], the filter should return an array of site IDs. Otherwise the filter should return an array of WP_Site objects.

Usage

add_filter( 'sites_pre_query', 'filter_function_name_2245', 10, 2 );
function filter_function_name_2245( $site_data, $this ){
	// filter...

	return $site_data;
}
$site_data(array/int/null)
Return an array of site data to short-circuit WP's site query, the site count as an integer if $this->query_vars['count'] is set, or null to run the normal queries.
$this(WP_Site_Query)
The WP_Site_Query instance, passed by reference.

Changelog

Since 5.2.0 Introduced.

Where the hook is called

WP_Site_Query::get_sites()
sites_pre_query
wp-includes/class-wp-site-query.php 310
$site_data = apply_filters_ref_array( 'sites_pre_query', array( $site_data, &$this ) );

Where in WP core the hook is used WordPress

Usage not found.