backups panels show only when the asset has data

plugins/backups/services/registry.py

@@ -59,8 +59,13 @@ class BackupKind:
     displayname = None
     storagebackend = 'shopdb'
     assettypes = ['*']
-    # Human note shown on the panel when there is nothing yet.
-    emptytext = 'No backups on record.'
+    # Text shown when the kind has no revisions for an asset. None means the
+    # panel HIDES entirely instead (the generic list renderer shows a panel
+    # only when it has rows or declares empty text). Default to hiding: a kind
+    # applies to an asset TYPE, but whether a given asset ever has this kind of
+    # backup is a property of the individual machine. A part marker panel on
+    # every one of 144 machines is noise, not information.
+    emptytext = None
 
     def parse(self, raw):
         """Opaque kinds return None; parseable kinds return the projection."""
@@ -118,7 +123,6 @@ class NtlarsKind(BackupKind):
     displayname = 'NTLARS / DNC Settings'
     storagebackend = 'shopdb'
     assettypes = ['machine']
-    emptytext = 'No NTLARS settings captured yet.'
 
     @staticmethod
     def embeddedmachineno(projection):
@@ -176,8 +180,10 @@ class NtlarsKind(BackupKind):
             'title': 'DNC Info',
             'assettypes': ['machine'],
             'endpoint': '/api/backups/asset/{assetid}/info?kind=ntlars',
+            # No 'empty' key: the keyvalue renderer decides visibility purely on
+            # field count and never displays empty text, so a machine with no
+            # NTLARS revision simply has no DNC Info card at all.
             'render': 'keyvalue',
-            'empty': 'No NTLARS settings captured for this machine yet.',
             # Above the history panels: this answers the question a tech
             # arrives with, while history is for the rarer restore case.
             'position': 38,
@@ -214,7 +220,6 @@ class PartMarkerKind(BackupKind):
     displayname = 'Part Marker Configuration'
     storagebackend = 'share'
     assettypes = ['machine', 'measuring_tool']
-    emptytext = 'No part marker backups on record.'
 
     def resolveassetid(self, payload):
         from shopdb.api import db, Asset