+ # collect relationships. currently done in one big block at the end;
+ # may need to move this upwards if people want automatic completion of
+ # relationships, i.e. deliver referenced objects like we do with ways...
+ relations = Array.new
+ if visible_nodes.length > 0
+ relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
+ "e.visible=1 and " +
+ "em.id = e.id and em.member_type='node' and em.member_id in (#{visible_nodes.keys.join(',')})")
+ end
+ if way_ids.length > 0
+ relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
+ "e.visible=1 and " +
+ "em.id = e.id and em.member_type='way' and em.member_id in (#{way_ids.join(',')})")
+ end
+ # we do not normally return the "other" partners referenced by an relation,
+ # e.g. if we return a way A that is referenced by relation X, and there's
+ # another way B also referenced, that is not returned. But we do make
+ # an exception for cases where an relation references another *relation*;
+ # in that case we return that as well (but we don't go recursive here)
+ relation_ids = relations.collect { |relation| relation.id }
+ if relation_ids.length > 0
+ relations += Relation.find_by_sql("select e.* from current_relations e,current_relation_members em where " +
+ "e.visible=1 and " +
+ "em.id = e.id and em.member_type='relation' and em.member_id in (#{relation_ids.join(',')})")
+ end
+
+ # this "uniq" may be slightly inefficient; it may be better to first collect and output
+ # all node-related relations, then find the *not yet covered* way-related ones etc.
+ relations.uniq.each do |relation|
+ doc.root << relation.to_xml_node(user_display_name_cache)
+ end
+
+ render :text => doc.to_s, :content_type => "text/xml"
+