#428

backend/app/controllers/tag_versions_controller.rb

@@ -36,6 +36,11 @@ class TagVersionsController < ApplicationController
 
   def serialise_versions rows, language_code
     rows = rows.to_a
+    tag_ids = rows.map(&:tag_id).uniq
+    current_names_by_tag_id = TagName.where(tag_id: tag_ids, language_code:, primary_flg: true)
+        .pluck(:tag_id, :name, :auto_generated).to_h do |id, name, automatic|
+      [id, { name:, auto_generated: automatic }]
+    end
     user_ids = rows.map(&:created_by_user_id).compact.uniq
     users_by_id = User.where(id: user_ids).pluck(:id, :name).to_h
     parent_ids = rows.flat_map do |row|
@@ -69,6 +74,7 @@ class TagVersionsController < ApplicationController
         event_type: row.event_type,
         names: row.names,
         name_changes: name_changes(row.names, row.attributes['prev_names']),
+        current_name_reference: current_names_by_tag_id[row.tag_id],
         name: { current: current_names['name'], prev: previous_names['name'] },
         category: { current: row.category, prev: row.attributes['prev_category'] },
         deprecated_at: { current: row.deprecated_at&.iso8601,

frontend/src/locales/ain-Kana/history.json

@@ -8,6 +8,8 @@
     "nameChanges.certified",
     "nameChanges.otherLanguages",
     "nameChanges.changed",
+    "nameChanges.currentReference",
+    "nameChanges.noNameRecord",
     "nameChanges.uncertified"
   ],
   "exportPath": "export_path",
@@ -32,6 +34,8 @@
   "confirmTag": "シロシ「{{name}}」　ウェㇽソン　{{version}}　ウン　アホシピレ　ヤ？\nピㇼカ　ヤ？",
   "restoreScope": "名称・別名は現在表示中の言語だけを差し戻します。全言語の名称は復元しません。",
   "nameChanges": {
+    "currentReference": "現行名・参考",
+    "noNameRecord": "この版には名称記録なし",
     "otherLanguages": "他言語情報",
     "changed": "（異動あり）",
     "uncertified": "（未公証）",

frontend/src/locales/ja/history.json

@@ -21,6 +21,8 @@
   "confirmTag": "タグ『{{name}}』を版 {{version}} に差戻します．\nよろしいですか?",
   "restoreScope": "名称・別名は現在表示中の言語だけを差し戻します。全言語の名称は復元しません。",
   "nameChanges": {
+    "currentReference": "現行名・参考",
+    "noNameRecord": "この版には名称記録なし",
     "otherLanguages": "他言語情報",
     "changed": "（異動あり）",
     "uncertified": "（未公証）",

frontend/src/pages/tags/TagHistoryPage.tsx

@@ -68,7 +68,7 @@ const snapshotNames = (names: TagVersion['names']): Record<string, TagNameSnapsh
 
 
 const renderPrimaryName = (
-    snapshot: TagNameSnapshot,
+    snapshot: Pick<TagNameSnapshot, 'name' | 'autoGenerated'>,
     language: string,
     label: (key: string) => ReactNode,
 ) => (
@@ -124,7 +124,6 @@ const TagVersionRows = ({ change, children }: {
   const language = localeLanguage (locale)
   const { message, label } = useUITranslation ('history')
   const { i18n } = useTranslation ('history')
-  const [expanded, setExpanded] = useState (false)
   const panelId = useId ()
   const names = snapshotNames (change.names)
   const nameChanges = (change.nameChanges ?? []).map (entry => ({
@@ -144,6 +143,9 @@ const TagVersionRows = ({ change, children }: {
       ? selected.prev
       : ((change.nameChanges != null && change.name.prev === change.name.current)
 	 ? current : legacyName (change.name.prev))
+  const missingNameRecord = current?.name == null && previous?.name == null
+  const [expansion, setExpansion] = useState ({ language, expanded: missingNameRecord })
+  const expanded = expansion.language === language ? expansion.expanded : missingNameRecord
   const otherLanguages = [...new Set ([...Object.keys (names),
       ...nameChanges.map (entry => entry.languageCode)])]
       .filter (code => code !== language).sort ()
@@ -151,13 +153,24 @@ const TagVersionRows = ({ change, children }: {
   const rowIds = otherLanguages.map ((_, index) => `${panelId}-${index}`)
   const primaryEqual = (prev: TagNameSnapshot | null, next: TagNameSnapshot | null) =>
       prev?.name === next?.name && prev?.autoGenerated === next?.autoGenerated
-  const primary = renderDiff ({ current, prev: previous },
+  const primary =
+      missingNameRecord
+      ? (
+	  <>
+	    {change.currentNameReference != null && (
+		<div>
+		  {renderPrimaryName (change.currentNameReference, language, label)}
+		  <span className="ml-2 text-sm">{label ('nameChanges.currentReference')}</span>
+		</div>)}
+	    <div className="text-sm">{label ('nameChanges.noNameRecord')}</div>
+	  </>)
+      : renderDiff ({ current, prev: previous },
 	  snapshot => renderPrimaryName (snapshot, language, label), primaryEqual)
   const toggle = otherLanguages.length > 0 && (
       <div className="mt-2 text-sm">
 	<button type="button" className="text-left"
 	    aria-expanded={expanded} aria-controls={rowIds.join (' ')}
-	    onClick={() => setExpanded (value => !value)}>
+	    onClick={() => setExpansion ({ language, expanded: !expanded })}>
 	  {label ('nameChanges.otherLanguages')}
 	  {otherChanges.length > 0 && label ('nameChanges.changed')}
 	  <span aria-hidden="true" className="ml-1">{expanded ? '▲' : '▼'}</span>

frontend/src/types.ts

@@ -378,12 +378,17 @@ export type TagNameChange = {
     current: TagNameSnapshot | null
     prev: TagNameSnapshot | null }
 
+export type CurrentNameReference = {
+    name: string
+    autoGenerated: boolean }
+
 export type TagVersion = {
     tagId:                  number
     versionNo:              number
     eventType:              'create' | 'update' | 'discard' | 'restore'
     names?:		 Record<string, TagNameSnapshot> | string | null
     nameChanges?:           TagNameChange[]
+    currentNameReference?:  CurrentNameReference | null
     name:                   { current: string | null; prev: string | null }
     category:               { current: Category; prev: Category | null }
     deprecatedAt:           { current: string | null; prev: string | null }