Extract feed and post serializer

src/actions/blog/feed.cr

@@ -1,50 +1,9 @@
 class Blog::Feed < ApiAction
-  @renderer = PostContentRenderer.new
-
   param page : Int32 = 1
 
   get "/feed.json" do
-    feed = {
-      "version"       => "https://jsonfeed.org/version/1",
-      "title"         => "racing · software · open-source",
-      "home_page_url" => Blog::Posts::Index.url,
-      "feed_url"      => Blog::Feed.url,
-      "description"   => Blog::Components::TAGLINE,
-      "author"        => {"name" => "Hannes Käufler"},
-      "favicon"       => "#{host}/favicon.ico",
-      "items"         => items,
-    }
-
-    if has_next_page
-      feed["next_url"] = Blog::Feed.with(page + 1).url
-    end
-
-    json(feed)
-  end
-
-  private def items
-    PostQuery.new.latest.map { |post| post_json(post) }
-  end
-
-  private def post_json(post : Post)
-    {
-      "id":             "#{post.id}",
-      "title":          post.title,
-      "content_html":   @renderer.render(post),
-      "url":            Blog::Posts::Show.with(post.slug).url,
-      "date_published": post.published_at.to_rfc3339,
-      "date_updated":   post.updated_at.to_rfc3339,
-    }
-  end
-
-  private def has_next_page
-    posts_count = PostQuery.new.published.count.to_i
-    not_last_page = page * PostQuery::PER_PAGE < posts_count
-    more_than_one_page = posts_count > PostQuery::PER_PAGE
-    more_than_one_page && not_last_page
-  end
-
-  private def host
-    Lucky::RouteHelper.settings.base_uri
+    json(FeedSerializer.new(PostQuery.new.latest.results,
+                            PostQuery.new.published.count,
+                            page))
   end
 end

src/app.cr

@@ -10,6 +10,7 @@ require "./pipes/**"
 require "./actions/**"
 require "./components/**"
 require "./pages/**"
+require "./serializers/**"
 require "./handlers/**"
 require "../config/env"
 require "../config/**"

src/serializers/feed_serializer.cr

@@ -0,0 +1,37 @@
+class FeedSerializer < Lucky::Serializer
+  def initialize(@posts : Array(Post), @total_posts : Int64, @page : Int32)
+  end
+
+  def render
+    feed = {
+      "version"       => "https://jsonfeed.org/version/1",
+      "title"         => "racing · software · open-source",
+      "home_page_url" => Blog::Posts::Index.url,
+      "feed_url"      => Blog::Feed.url,
+      "description"   => Blog::Components::TAGLINE,
+      "author"        => {"name" => "Hannes Käufler"},
+      "favicon"       => "#{host}/favicon.ico",
+      "items"         => items,
+    }
+
+    if has_next_page
+      feed["next_url"] = Blog::Feed.with(@page + 1).url
+    end
+
+    feed
+  end
+
+  private def items
+    @posts.map { |post| PostSerializer.new(post).render }
+  end
+
+  private def has_next_page
+    not_last_page = @page * PostQuery::PER_PAGE < @total_posts
+    more_than_one_page = @total_posts > PostQuery::PER_PAGE
+    more_than_one_page && not_last_page
+  end
+
+  private def host
+    Lucky::RouteHelper.settings.base_uri
+  end
+end

src/serializers/post_serializer.cr

@@ -0,0 +1,17 @@
+class PostSerializer < Lucky::Serializer
+  @renderer = PostContentRenderer.new
+
+  def initialize(@post : Post)
+  end
+
+  def render
+    {
+      id:             "#{@post.id}",
+      title:          @post.title,
+      content_html:   @renderer.render(@post),
+      url:            Blog::Posts::Show.with(@post.slug).url,
+      date_published: @post.published_at.to_rfc3339,
+      date_updated:   @post.updated_at.to_rfc3339,
+    }
+  end
+end