From 878df847bac8cffb5452af30c3270fbdd6050651 Mon Sep 17 00:00:00 2001
From: Daniel Friesel <derf@finalrewind.org>
Date: Sun, 20 Sep 2020 10:52:21 +0200
Subject: defer route detail rendering until all requests have completed

---
 lib/DBInfoscreen/Controller/Stationboard.pm | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

(limited to 'lib')

diff --git a/lib/DBInfoscreen/Controller/Stationboard.pm b/lib/DBInfoscreen/Controller/Stationboard.pm
index 220e630..9706b39 100644
--- a/lib/DBInfoscreen/Controller/Stationboard.pm
+++ b/lib/DBInfoscreen/Controller/Stationboard.pm
@@ -442,8 +442,10 @@ sub render_train {
 
 	$self->render_later;
 
-	# if wagonorder->is_available_p takes longer than get_route_timestamps_p,
-	# we'll have a useless (non-working) wagonorder link. That's okay.
+	my $wagonorder_req  = Mojo::Promise->new;
+	my $stationinfo_req = Mojo::Promise->new;
+	my $route_req       = Mojo::Promise->new;
+
 	if ( $departure->{wr_link} ) {
 		$self->wagonorder->is_available_p( $result, $departure->{wr_link} )
 		  ->then(
@@ -455,11 +457,14 @@ sub render_train {
 				$departure->{wr_link} = undef;
 				return;
 			}
+		)->finally(
+			sub {
+				$wagonorder_req->resolve;
+				return;
+			}
 		)->wait;
 	}
 
-	# Same for stationinfo (direction of travel). If it's too late and
-	# therefore missing, that's okay.
 	$self->wagonorder->get_stationinfo_p( $result->station_uic )->then(
 		sub {
 			my ($station_info)    = @_;
@@ -505,6 +510,11 @@ sub render_train {
 			# errors don't matter here
 			return;
 		}
+	)->finally(
+		sub {
+			$stationinfo_req->resolve;
+			return;
+		}
 	)->wait;
 
 	$self->hafas->get_route_timestamps_p( train => $result )->then(
@@ -603,6 +613,14 @@ sub render_train {
 			# nop
 		}
 	)->finally(
+		sub {
+			$route_req->resolve;
+			return;
+		}
+	)->wait;
+
+	# Defer rendering until all requests have completed
+	Mojo::Promise->all( $wagonorder_req, $stationinfo_req, $route_req )->then(
 		sub {
 			$self->render(
 				'_train_details',
-- 
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