show year in timeline for music/book/game in addition to movies

books/models.py

@@ -120,6 +120,10 @@ class Book(Entity):
         else:
             return [self]  # Book.objects.filter(id=self.id)
 
+    @property
+    def year(self):
+        return self.pub_year
+
     @property
     def verbose_category_name(self):
         return _("书籍")

games/models.py

@@ -98,6 +98,10 @@ class Game(Entity):
     def get_absolute_url(self):
         return reverse("games:retrieve", args=[self.id])
 
+    @property
+    def year(self):
+        return self.release_date.year if self.release_date else None
+
     @property
     def wish_url(self):
         return reverse("games:wish", args=[self.id])

music/models.py

@@ -55,6 +55,10 @@ class Album(Entity):
 
     history = HistoricalRecords()
 
+    @property
+    def year(self):
+        return self.release_date.year if self.release_date else None
+
     def __str__(self):
         return self.title