streamline the feed controller with put_root_layout plug, write post about it

lib/home73k_web/controllers/feed_controller.ex

@@ -1,5 +1,7 @@
 defmodule Home73kWeb.FeedController do
   use Home73kWeb, :controller
+  plug :put_layout, false
+  plug :put_root_layout, false
 
   alias Home73k.Blog
 
@@ -9,7 +11,6 @@ defmodule Home73kWeb.FeedController do
 
     conn
     |> put_resp_content_type("application/rss+xml")
-    |> put_layout(:false)
     |> render("rss.xml", posts: posts, last_build_date: last_build_date)
   end
 end

lib/home73k_web/live/blog_live.html.leex

@@ -26,7 +26,7 @@
           </div>
 
           <%= if length(post.tags) > 0 do %>
-            <div class="post-tags fs-smaller mb-3">
+            <div class="post-tags fs-smaller mb-4">
             <%= icon_div @socket, "mdi-tag-multiple", [class: "icon baseline text-gray-300"] %>
             <%= for {tag, i} <- Enum.with_index(post.tags) do %>
               <span class="text-gray-300">#</span><%= live_redirect tag, to: Routes.blog_path(@socket, :tag, tag) %><%= i < (length(post.tags) - 1) && "," || "" %>

lib/home73k_web/router.ex

@@ -3,7 +3,7 @@ defmodule Home73kWeb.Router do
   alias Home73kWeb.CSPHeader
 
   pipeline :browser do
-    plug :accepts, ["html"]
+    plug :accepts, ~w(html xml)
     plug :fetch_session
     plug :fetch_live_flash
     plug :put_root_layout, {Home73kWeb.LayoutView, :root}
@@ -12,10 +12,6 @@ defmodule Home73kWeb.Router do
     plug CSPHeader
   end
 
-  pipeline :xml_rss do
-    plug :accepts, ["xml", "rss", "atom"]
-  end
-
   pipeline :api do
     plug :accepts, ["json"]
   end
@@ -36,13 +32,9 @@ defmodule Home73kWeb.Router do
     live "/blog/page/:page", BlogLive, :page
     live "/blog/tag/:tag", BlogLive, :tag
     live "/blog/:id", BlogLive, :show
-  end
-
-  scope "/feed", Home73kWeb do
-    pipe_through :xml_rss
 
     # Feeds
-    get "/", FeedController, :rss
+    get "/feed", FeedController, :rss
   end
 
   # Other scopes may use custom stacks.

priv/content/2021/04/2021-04-07_rss-feed-phoenix-liveview.md

@@ -0,0 +1,32 @@
+---
+%{
+  title: "RSS Feed When Using Elixir Phoenix LiveView",
+  id: "rss-feed-elixir-phoenix-liveview",
+  date: ~N[2021-04-07 12:31:00],
+  author: "Adam Piontek",
+  tags: ~w(tech elixir phoenix liveview coding routing rss feed development)
+}
+---
+
+While [re-implementing my website in elixir/phoenix](/blog/blog-incorporated-2021), I wanted to include an RSS feed for the blog posts. Luckily I found pretty much everything I needed in Daniel Wachtel's [Building an RSS Feed with Phoenix](https://danielwachtel.com/phoenix/building-rss-feed-phoenix) post, but since I'm making use of LiveView, I ran into one hiccup --- errors about a missing `root.xml` layout!
+
+<!--more-->
+
+LiveView changes how Phoenix handles layouts --- there's a `root.html.leex` layout, and then for live views, a `live.html.leex` sub-layout, and for regular controller views, an `app.html.eex` sub-layout.
+
+Without LiveView, Daniel's controller directive `plug :put_layout, false`{:.lang-elixir} would be enough, but with LiveView, Phoenix is still looking for the *root* layout template, which for my `index.html` would be `root.xml` ... what to do?
+
+One option would be to create a whole separate router pipeline to skip the `plug :put_root_layout, {Home73kWeb.LayoutView, :root}`{:.lang-elixir} directive. It would work, but is a heavier approach.
+
+But luckily, there's a new [put_root_layout/2](https://hexdocs.pm/phoenix/Phoenix.Controller.html#put_root_layout/2) that we can leverage like so:
+
+```elixir
+defmodule YourAppWeb.RSSController do
+  use YourAppWeb, :controller
+  plug :put_layout, false
+
+  ...
+end
+```
+
+With this in place, the rss xml is served plain, just like we want.