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filter is not described

network_allowed_themes filter-hook . WP 4.5.0

Filters the array of themes allowed on the network.

Site is provided as context so that a list of network allowed themes can be filtered further.

Usage

add_filter( 'network_allowed_themes', 'filter_function_name_6101', 10, 2 );
function filter_function_name_6101( $allowed_themes, $blog_id ){
	// filter...

	return $allowed_themes;
}
$allowed_themes(array)
An array of theme stylesheet names.
$blog_id(int)
ID of the site.

Where the hook is called

WP_Theme::get_allowed()
wp-includes/class-wp-theme.php 1273
$network = (array) apply_filters( 'network_allowed_themes', self::get_allowed_on_network(), $blog_id );

Where the hook is used (in WP core)

Does not used.