latin: prefer cached json of static data include

[sheet.git] / common.inc.plp

diff --git a/common.inc.plp b/common.inc.plp
index 71c5c1379f29aeb82d6d1211ec53dff69740d2cf..afec9d11f2172bb2130301eaf7468422a86020a2 100644 (file)
--- a/common.inc.plp
+++ b/common.inc.plp
@@ -99,6 +99,24 @@ sub checkmodified {
        $header{'Last-Modified'} = time2str($lastmod);
 }
 
+sub Data {
+       my ($filename) = @_;
+       my @data = eval {
+               open my $cache, '<:raw', "data/$filename.json"
+                       or return do "$filename.inc.pl"; # silent fallback to original code
+               require JSON;
+               local $/; # slurp
+               return JSON::decode_json(readline $cache);
+       };
+       if ($! or $@ or !@data or !$data[0]) {
+               die ['Table data not found', $@ || $!];
+       }
+       if (@data == 1 and ref $data[0] eq 'HASH' and not %{$data[0]}) {
+               die ['Table data missing'];
+       }
+       return wantarray ? @data : $data[0]; # list compatibility like do does
+}
+
 sub Html {
        my ($meta) = @_;