Ensure that invisible post and comments don't appear in What's Happen…

…ing.

See cuny-academic-commons/commons-in-a-box#466.

lib/media-funcs.php

@@ -139,6 +139,36 @@ function openlab_whats_happening_activity_items() {
 
 		$a      = bp_activity_get( $activity_args );
 		$cached = $a['activities'];
+
+		// Post-query filter to ensure that no "invisible" post items are included.
+		$cached = array_filter(
+			$cached,
+			function( $activity ) {
+				if ( 'groups' !== $activity->component ) {
+					return true;
+				}
+
+				if ( 'new_blog_post' !== $activity->type && 'new_blog_comment' !== $activity->type ) {
+					return true;
+				}
+
+				$site_id = openlab_get_site_id_by_group_id( $activity->item_id );
+
+				$invisible_post_ids = openlab_get_invisible_post_ids( $site_id );
+
+				if ( 'new_blog_post' === $activity->type ) {
+					$post_id = $activity->secondary_item_id;
+				} else {
+					switch_to_blog( $site_id );
+					$comment = get_comment( $activity->secondary_item_id );
+					$post_id = (int) $comment->comment_post_ID;
+					restore_current_blog();
+				}
+
+				return ! in_array( $post_id, $invisible_post_ids, true );
+			}
+		);
+
 		wp_cache_set( 'whats_happening_items', $cached, 'openlab' );
 	}