Use link[rel=prefetch] to preload chapter pages

docs/changelog.rst

@@ -5,6 +5,7 @@ v0.9.5
 ^^^^^^
 
 * Removed Reddit OAuth provider
+* Reduced prefetched pages from 3 to 2
 
 v0.9.4
 ^^^^^^

reader/templates/chapter.html

@@ -24,6 +24,11 @@
   <link href="{% static 'COMPILED/styles/chapter.css' %}"
         rel="stylesheet preload" type="text/css" as="style">
 {% endblock %}
+{% block head_extras %}
+  {% for page in prefetch %}
+    <link href="{{ page.image.url }}" rel="prefetch" as="image">
+  {% endfor %}
+{% endblock %}
 {% block title %}
   <meta name="title" content="{{ curr_chapter.title }}">
   {% with title=curr_chapter.series.title|add:' ~ '|add:config.NAME %}
@@ -128,9 +133,4 @@ <h1>
       </section>
     {% endwith %}
   </div>
-  <div id="preload" class="no-display">
-    {% for page in preload %}
-      <img alt="preload" src="{{ page.image.url }}">
-    {% endfor %}
-  </div>
 {% endblock %}

reader/views.py

@@ -218,8 +218,8 @@ def chapter_page(request: HttpRequest, slug: str, vol: int,
         curr_page = next(p for p in all_pages if p.number == page)
     except StopIteration as e:  # pragma: no cover
         raise Http404('No such page') from e
-    preload = list(filter(
-        lambda p: curr_page < p < curr_page.number + 4, all_pages
+    prefetch = list(filter(
+        lambda p: curr_page < p < curr_page.number + 3, all_pages
     ))
     tags = current.series.categories.values_list('name', flat=True)
     url = request.path
@@ -237,7 +237,7 @@ def chapter_page(request: HttpRequest, slug: str, vol: int,
         'prev_chapter': prev_,
         'all_pages': all_pages,
         'curr_page': curr_page,
-        'preload': preload,
+        'prefetch': prefetch,
         'breadcrumbs': crumbs,
         'tags': ','.join(tags)
     })