Custom Collector with `sub_registry_with_prefix` outputs name multiple times

[allada]

If you create a custom Collector and attach it to a sub registry it appends the name improperly.

#[derive(Debug)]
struct MyCollector {}

impl prometheus_client::collector::Collector for MyCollector {
  fn collect<'a>(&'a self) -> Box<dyn Iterator<Item = (std::borrow::Cow<'a, prometheus_client::registry::Descriptor>, prometheus_client::MaybeOwned<'a, Box<dyn prometheus_client::registry::LocalMetric>>)> + 'a> {
    let c: Box<dyn prometheus_client::registry::LocalMetric> = Box::new(prometheus_client::metrics::counter::ConstCounter::new(42));
    let descriptor = prometheus_client::registry::Descriptor::new(
      "my_counter",
      "This is my counter",
      None,
      None,
      vec![],
    );
    Box::new(std::iter::once((std::borrow::Cow::Owned(descriptor), prometheus_client::MaybeOwned::Owned(c))))
  }
}

let my_collector = Box::new(MyCollector{});    
{
    let mut root_registry = <Registry>::with_prefix("root");
    let r = root_registry.sub_registry_with_prefix("000");
    let r = r.sub_registry_with_prefix("111");
    let r = r.sub_registry_with_prefix("222");
    r.register_collector(my_collector);
}

Results:

# HELP root_root_000_root_000_111_root_000_111_222_my_counter This is my counter.....
# TYPE root_root_000_root_000_111_root_000_111_222_my_counter counter
root_root_000_root_000_111_root_000_111_222_my_counter_total 42
# EOF

Expected:

# HELP root_000_111_222_my_counter This is my counter.....
# TYPE root_000_111_222_my_counter counter
root_000_111_222_my_counter_total 42
# EOF

[jenisnavadiya]

Same issue

[felixdollack]

I noticed the same. It seems state is only kept when the previous screen is part of the location stack.

E.g. going from LocationA -> LocationB

class LocationB extends BeamLocation<BeamState> {
  @override
  List<BeamPage> buildPages(BuildContext context, BeamState state) {
    return [
      // create whatever (back)stack you desire here.
      // this will also keep the current state of this location in memory
      ...LocationA().buildPages(context, state),
      const WidgetB(),
    ];
  }

  @override
  List<Pattern> get pathPatterns => ["/b"];
}

Disclaimer: I just started using beamer 2 days ago. There could be another way I don't know yet ^^;

[felixdollack]

There was also this comment that could be useful