Gracefully handle template errors; Add diagnostics

MWTemplate.pm

@@ -5,9 +5,14 @@ use v5.30;
 use feature "signatures";
 no warnings "experimental::signatures";
 
+my $DEBUG = 1;
+
 sub Parse($input, $template_name)
 {
+	# say STDERR "Looking for $template_name in:";
+	# say STDERR $input;
 	my ($contents) = $input =~ /\{\{ \s* $template_name \s* \| (.*) \}\}/sx;
+	return 0 unless $contents;
 	my @params = split /\|/, $contents;
 	my @positional_params;
 	my %named_params;

wiki-tile.pl

@@ -76,6 +76,8 @@ foreach my $page (values %{$region_query_results->{query}{pages}})
 	next if $page->{title} =~ /^Category:/;
 	my $region = $grid->make_region($page->{title});
 	my $parsed_template = MWTemplate::Parse($page->{revisions}[0]{'*'}, $region_template_name);
+	next unless $parsed_template;
+	say STDERR "Processing region: $page->{title}";
 	$region->{defaults}{colour} = $parsed_template->{named_params}{colour};
 	if($regiondir)
 	{
@@ -114,6 +116,8 @@ foreach my $page (values %{$subregion_query_results->{query}{pages}})
 {
 	next if $page->{title} =~ /^Category:/;
 	my $parsed_template = MWTemplate::Parse($page->{revisions}[0]{'*'}, $subregion_template_name);
+	next unless $parsed_template;
+	say STDERR "Processing subregion: $page->{title}";
 	my $subregion = $grid->make_region($page->{title});
 	$subregion->{defaults}{colour} = $parsed_template->{named_params}{colour};
 	if($regiondir)
@@ -139,6 +143,7 @@ foreach my $page (values %{$background_query_results->{query}{pages}})
 {
 	if($page->{imageinfo})
 	{
+		say STDERR "Processing image: $page->{title}";
 		foreach my $region (@{$background_pages{$page->{title}}})
 		{
 			$region->{defaults}{image} = $page->{imageinfo}[0]{url};
@@ -161,6 +166,7 @@ foreach my $page (values %{$tile_query_results->{query}{pages}})
 {
 	my $content = $page->{revisions}[0]{'*'};
 	my ($region_name) = $page->{title} =~ /(.*)\/Tiles/;
+	say STDERR "Processing tiles for: $region_name";
 	my $region = $grid->{regions}{$region_name};
 	foreach my $coords (split /;/, $content)
 	{
@@ -188,6 +194,8 @@ foreach my $page (values %{$location_query_results->{query}{pages}})
 {
 	next if $page->{title} =~ /^Category:/;
 	my $parsed_template = MWTemplate::Parse($page->{revisions}[0]{'*'}, $location_template_name);
+	next unless $parsed_template;
+	say STDERR "Processing location: $page->{title}";
 	my $location = $grid->make_region($page->{title});
 	$location->{defaults}{colour} = $parsed_template->{named_params}{colour};
 
@@ -209,7 +217,6 @@ foreach my $page (values %{$location_query_results->{query}{pages}})
 		$location_with_context->{defaults}{colour} = $location->{defaults}{colour};
 	}
 
-	# The below regex is a whitespace forgiving version of /^(-?\d+),(-?\d+)/, an int pair
 	if($parsed_template->{positional_params}[0] =~ $coords_regex)
 	{
 		$location->make_tile_at($1,$2);
@@ -257,6 +264,7 @@ foreach my $site_page_ref (values %{$site_query_results->{query}{pages}})
 	my $site_url = $site_page_ref->{canonicalurl};
 	my $site_content = $site_page_ref->{revisions}[0]{'*'};
 	my $parsed_template = MWTemplate::Parse($site_content, $site_template_name);
+	next unless $parsed_template;
 	my ($nw,$sw) = split /,/, $parsed_template->{named_params}{coords};
 
 	my $imageinfo_query_results = $mw->api({ action => 'query',