is_user_member_of_blog( int $user_id = 0, int $blog_id = 0 ): bool

1163function is_user_member_of_blog( $user_id = 0, $blog_id = 0 ) {1164	global $wpdb;1165 1166	$user_id = (int) $user_id;1167	$blog_id = (int) $blog_id;1168 1169	if ( empty( $user_id ) ) {1170		$user_id = get_current_user_id();1171	}1172 1173	/*1174	 * Technically not needed, but does save calls to get_site() and get_user_meta()1175	 * in the event that the function is called when a user isn't logged in.1176	 */1177	if ( empty( $user_id ) ) {1178		return false;1179	} else {1180		$user = get_userdata( $user_id );1181		if ( ! $user instanceof WP_User ) {1182			return false;1183		}1184	}1185 1186	if ( ! is_multisite() ) {1187		return true;1188	}1189 1190	if ( empty( $blog_id ) ) {1191		$blog_id = get_current_blog_id();1192	}1193 1194	$blog = get_site( $blog_id );1195 1196	if ( ! $blog || ! isset( $blog->domain ) || $blog->archived || $blog->spam || $blog->deleted ) {1197		return false;1198	}1199 1200	if ( 1 === $blog_id ) {1201		$capabilities_key = $wpdb->base_prefix . 'capabilities';1202	} else {1203		$capabilities_key = $wpdb->base_prefix . $blog_id . '_capabilities';1204	}1205 1206	$has_cap   = get_user_meta( $user_id, $capabilities_key, true );1207	$is_member = is_array( $has_cap );1208 1209	/**1210	 * Filters whether the user is a member of a given blog.1211	 *1212	 * This filter only runs when the user and blog have both been resolved1213	 * to valid records on a multisite installation; it is not invoked for1214	 * logged-out requests, unknown users, or archived/spammed/deleted sites.1215	 *1216	 * @since 7.1.01217	 *1218	 * @param bool $is_member Whether the user is a member of the blog.1219	 * @param int  $user_id   The user ID being checked.1220	 * @param int  $blog_id   The blog ID being checked.1221	 */1222	return (bool) apply_filters( 'is_user_member_of_blog', $is_member, $user_id, $blog_id );1223}