Cache title author snippet

bookwyrm/models/author.py

@@ -1,6 +1,8 @@
 """ database schema for info about authors """
 import re
 from django.contrib.postgres.indexes import GinIndex
+from django.core.cache import cache
+from django.core.cache.utils import make_template_fragment_key
 from django.db import models
 
 from bookwyrm import activitypub
@@ -34,6 +36,17 @@ class Author(BookDataModel):
     )
     bio = fields.HtmlField(null=True, blank=True)
 
+    def save(self, *args, **kwargs):
+        """clear related template caches"""
+        # clear template caches
+        cache_keys = [
+            make_template_fragment_key("titleby", [book])
+            for book in self.book_set.values_list("id", flat=True)
+        ]
+        cache.delete_many(cache_keys)
+
+        return super().save(*args, **kwargs)
+
     @property
     def isni_link(self):
         """generate the url from the isni id"""

bookwyrm/models/book.py

@@ -3,6 +3,8 @@ import re
 
 from django.contrib.postgres.search import SearchVectorField
 from django.contrib.postgres.indexes import GinIndex
+from django.core.cache import cache
+from django.core.cache.utils import make_template_fragment_key
 from django.db import models, transaction
 from django.db.models import Prefetch
 from django.dispatch import receiver
@@ -185,6 +187,11 @@ class Book(BookDataModel):
         """can't be abstract for query reasons, but you shouldn't USE it"""
         if not isinstance(self, Edition) and not isinstance(self, Work):
             raise ValueError("Books should be added as Editions or Works")
+
+        # clear template caches
+        cache_key = make_template_fragment_key("titleby", [self.id])
+        cache.delete(cache_key)
+
         return super().save(*args, **kwargs)
 
     def get_remote_id(self):

bookwyrm/templates/snippets/book_titleby.html

@@ -1,6 +1,8 @@
 {% load i18n %}
 {% load utilities %}
+{% load cache %}
 {% spaceless %}
+{% cache None titleby book.id %}
 
 {% if book.authors.exists %}
 {% blocktrans trimmed with path=book.local_path title=book|book_title %}
@@ -10,4 +12,6 @@
 {% else %}
 <a href="{{ book.local_path }}">{{ book|book_title }}</a>
 {% endif %}
+
+{% endcache %}
 {% endspaceless %}