AO3-7165 Fix picking skin from chooser without javascript

app/helpers/skin_cache_helper.rb

@@ -19,10 +19,23 @@ def skin_cache_version_update(skin_id)
   end
 
   def skin_chooser_key
-    [:v2, :skin_chooser]
+    [:v3, :skin_chooser]
   end
 
   def skin_chooser_expire_cache
-    ActionController::Base.new.expire_fragment(skin_chooser_key)
+    Rails.cache.delete(skin_chooser_key)
+  end
+
+  def skin_chooser_data
+    Rails.cache.fetch(skin_chooser_key) do
+      Skin.in_chooser.order(:title).map do |skin|
+        {
+          title: skin.title,
+          # Cache the parameters that we need for generating the skin URL later
+          # We can't cache the record itself (for later URL generation) since it could change or be deleted
+          param: skin.to_param
+        }
+      end
+    end
   end
 end

app/models/skin.rb

@@ -61,7 +61,7 @@ class Skin < ApplicationRecord
 
   after_save :skin_invalidate_cache
   def skin_invalidate_cache
-    skin_chooser_expire_cache
+    skin_chooser_expire_cache if saved_change_to_in_chooser? || in_chooser?
     skin_cache_version_update(id)
 
     # Work skins can't have children, but site skins (which have type nil)

app/views/layouts/_footer.html.erb

@@ -3,18 +3,17 @@
   <h3 class="landmark heading"><%= t(".landmark") %></h3>
   <ul class="navigation actions">
     <% if logged_in? || logged_in_as_admin? %>
-      <% cache(skin_chooser_key, skip_digest: true) do %>
-        <% unless Skin.in_chooser.empty? %>
-          <li class="module group">
-            <h4 class="heading"><%= t(".customize.header") %></h4>
-            <ul class="menu">
-              <li><%= button_to t(".customize.default"), unset_skins_path, method: :post %></li>
-              <% Skin.in_chooser.order(:title).each do |s| %>
-                <li><%= button_to s.title, set_skin_path(s), method: :post %></li>
-              <% end %>
-            </ul>
-          </li>
-        <% end %>
+      <% skins = skin_chooser_data %>
+      <% unless skins.empty? %>
+        <li class="module group">
+          <h4 class="heading"><%= t(".customize.header") %></h4>
+          <ul class="menu">
+            <li><%= button_to t(".customize.default"), unset_skins_path, method: :post %></li>
+            <% skins.each do |s| %>
+              <li><%= button_to s[:title], set_skin_path(s[:param]), method: :post %></li>
+            <% end %>
+          </ul>
+        </li>
       <% end %>
     <% end %>
     <li class="module group">