Add RSS feed support for index and tag feeds

apps/mebe_engine/lib/models.ex

@@ -25,9 +25,4 @@ defmodule MebeEngine.Models do
       title: nil,
       content: nil
   end
-
-  defmodule Archive do
-    defstruct key: nil,
-      posts: nil
-  end
 end

apps/mebe_web/config/config.exs.dist

@@ -17,8 +17,11 @@ config :mebe_web, MebeWeb.Endpoint,
 config :blog_config,
   blog_name: "My awesome blog",
   blog_author: "Author McAuthor",
+  absolute_url: "http://localhost:4000", # Absolute URL to the site without trailing slash, including protocol
+  enable_feeds: false, # Set to true to enable RSS feeds
 
   posts_per_page: 10,
+  posts_in_feed: 20,
 
   # Disqus comments
   disqus_comments: false, # Use Disqus comments

apps/mebe_web/web/controllers/controller_utils.ex

@@ -0,0 +1,40 @@
+defmodule MebeWeb.ControllerUtils do
+  use MebeWeb.Web, :controller
+
+  @moduledoc """
+  This module contains the common functions for all controllers.
+  """
+
+  @blog_name Application.get_env(:blog_config, :blog_name)
+  @blog_author Application.get_env(:blog_config, :blog_author)
+  @absolute_url Application.get_env(:blog_config, :absolute_url)
+  @posts_per_page Application.get_env(:blog_config, :posts_per_page)
+  @disqus_comments Application.get_env(:blog_config, :disqus_comments)
+  @page_commenting Application.get_env(:blog_config, :page_commenting)
+  @disqus_shortname Application.get_env(:blog_config, :disqus_shortname)
+
+  @doc """
+  Render a list of posts with the given template and params. The posts
+  and generic configuration settings are assigned to the connection.
+  """
+  def render_posts(conn, posts, template, _params) do
+    conn
+    |> insert_config
+    |> assign(:posts, posts)
+    |> render(template)
+  end
+
+  @doc """
+  Insert common config variables to the assigns table for the connection
+  """
+  def insert_config(conn) do
+    conn
+    |> assign(:blog_name, @blog_name)
+    |> assign(:blog_author, @blog_author)
+    |> assign(:absolute_url, @absolute_url)
+    |> assign(:posts_per_page, @posts_per_page)
+    |> assign(:disqus_comments, @disqus_comments)
+    |> assign(:page_commenting, @page_commenting)
+    |> assign(:disqus_shortname, @disqus_shortname)
+  end
+end

apps/mebe_web/web/controllers/feed_controller.ex

@@ -0,0 +1,35 @@
+defmodule MebeWeb.FeedController do
+  use MebeWeb.Web, :controller
+
+  alias MebeEngine.DB
+  import MebeWeb.ControllerUtils, only: [render_posts: 4]
+
+  plug :put_resp_content_type, "application/rss+xml"
+  plug :put_layout_formats, ["xml"]
+  plug :put_layout, "feed.xml"
+
+  @posts_in_feed Application.get_env(:blog_config, :posts_in_feed)
+
+  def index(conn, params) do
+    posts = DB.get_reg_posts 0, @posts_in_feed
+
+    conn
+    |> render_posts(posts, "postlist.xml", params)
+  end
+
+  def tag(conn, params) do
+    %{"tag" => tag} = params
+
+    posts = DB.get_tag_posts tag, 0, @posts_in_feed
+
+    conn
+    |> assign(:tag, tag)
+    |> render_posts(posts, "postlist.xml", params)
+  end
+
+  defp put_headers(conn, key_values) do
+    Enum.reduce key_values, conn, fn {k, v}, conn ->
+      Plug.Conn.put_resp_header(conn, k, v)
+    end
+  end
+end

apps/mebe_web/web/controllers/page_controller.ex

@@ -2,6 +2,7 @@ defmodule MebeWeb.PageController do
   use MebeWeb.Web, :controller
 
   alias MebeEngine.DB
+  import MebeWeb.ControllerUtils, only: [render_posts: 4, insert_config: 1]
 
   @posts_per_page Application.get_env(:blog_config, :posts_per_page)
 
@@ -119,7 +120,6 @@ defmodule MebeWeb.PageController do
     end
   end
 
-
   # Render a list page (a list of posts) or 404 if no posts could be found.
   # The postgetter should be an anonymous function which returns a list of
   # posts when called, or an empty list if none are found. The function gets
@@ -134,13 +134,11 @@ defmodule MebeWeb.PageController do
 
       posts ->
         conn
-        |> insert_config
-        |> assign(:posts, posts)
         |> assign(:total_count, total_count)
         |> assign(:current_page, page)
         |> assign(:page_type, page_type)
         |> assign(:page_args, page_args)
-        |> render(template)
+        |> render_posts(posts, template, params)
     end
   end
 
@@ -167,15 +165,4 @@ defmodule MebeWeb.PageController do
     |> put_status(:not_found)
     |> render(MebeWeb.ErrorView, :"404")
   end
-
-  # Insert config variables to the assigns table for the connection
-  defp insert_config(conn) do
-    conn
-    |> assign(:blog_name, Application.get_env(:blog_config, :blog_name))
-    |> assign(:blog_author, Application.get_env(:blog_config, :blog_author))
-    |> assign(:posts_per_page, @posts_per_page)
-    |> assign(:disqus_comments, Application.get_env(:blog_config, :disqus_comments))
-    |> assign(:page_commenting, Application.get_env(:blog_config, :page_commenting))
-    |> assign(:disqus_shortname, Application.get_env(:blog_config, :disqus_shortname))
-  end
 end

apps/mebe_web/web/router.ex

@@ -1,10 +1,11 @@
 defmodule MebeWeb.Router do
   use Phoenix.Router
 
+  @enable_feeds Application.get_env(:blog_config, :enable_feeds)
 
   pipeline :browser do
     plug MebeWeb.RequestStartTimePlug
-    plug :accepts, ["html"]
+    plug :accepts, ["html", "xml"]
     plug :fetch_session
     plug :fetch_flash
   end
@@ -14,9 +15,11 @@ defmodule MebeWeb.Router do
 
     get "/p/:page", PageController, :index
     get "/", PageController, :index
+    if @enable_feeds, do: (get "/feed", FeedController, :index)
 
     get "/tag/:tag/p/:page", PageController, :tag
     get "/tag/:tag", PageController, :tag
+    if @enable_feeds, do: (get "/tag/:tag/feed", FeedController, :tag)
 
     get "/archive/:year/p/:page", PageController, :year
     get "/archive/:year", PageController, :year

apps/mebe_web/web/templates/feed/postlist.xml.eex

@@ -0,0 +1,41 @@
+<%= for post <- @posts do %>
+  <% {year, month, day} = post.date %>
+
+  <%
+  # Justified versions of the month and day
+  {j_month, j_day} = {
+    String.rjust(Integer.to_string(month), 2, ?0),
+    String.rjust(Integer.to_string(day), 2, ?0)
+  }
+  %>
+
+  <%
+  # Quick and dirty RFC 822 month converter
+  rfc_month = Enum.at(["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"], month - 1)
+
+  data = [0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4]
+  dow_year = if month < 3, do: year - 1, else: year
+  dow = rem(dow_year + div(dow_year, 4) - div(dow_year, 100) + div(dow_year, 400) + Enum.at(data, month - 1) + day, 7)
+  dow_str = Enum.at(["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"], dow - 1)
+  %>
+
+  <item>
+    <title>
+      <![CDATA[<%= post.title %>]]>
+    </title>
+    <link><%= @absolute_url %><%= page_path @conn, :post, year, j_month, j_day, post.slug %></link>
+    <guid><%= @absolute_url %><%= page_path @conn, :post, year, j_month, j_day, post.slug %></guid>
+    <description>
+      <![CDATA[
+
+      <%= post.short_content %>
+
+      <a href="<%= @absolute_url %><%= page_path @conn, :post, year, j_month, j_day, post.slug %>">
+        Read more…
+      </a>
+
+      ]]>
+    </description>
+    <pubDate><%= dow_str %>, <%= day %> <%= rfc_month %> <%= year %> 00:00:00 UT</pubDate>
+  </item>
+<% end %>

apps/mebe_web/web/templates/layout/app.html.eex

@@ -8,13 +8,19 @@
 
     <title><%= title @conn %></title>
     <link rel="stylesheet" href="<%= static_path(@conn, "/css/app.css") %>">
+    
+    <%= if assigns[:page_type] == :tag do %>
+      <link href="<%= @absolute_url %><%= feed_path @conn, :tag, @tag %>" rel="alternate" type="application/rss+xml" title="RSS feed for tag <%= @tag %>" />
+    <% else %>
+      <link href="<%= @absolute_url %><%= feed_path @conn, :index %>" rel="alternate" type="application/rss+xml" title="RSS feed" />
+    <% end %>
   </head>
 
   <body>
     <div class="navbar navbar-default">
       <div class="container-fluid">
         <div class="navbar-header">
-          <a href="<%= page_path @conn, :index, 1 %>" class="navbar-brand">
+          <a href="<%= @absolute_url %>" class="navbar-brand">
             <%= Application.get_env :blog_config, :blog_name %>
           </a>
         </div>

apps/mebe_web/web/templates/layout/feed.xml.eex

@@ -0,0 +1,10 @@
+<rss version="2.0">
+  <channel>
+    <title><%= title @conn %></title>
+    <link><%= @absolute_url %></link>
+    <description></description>
+    <generator>Mebe</generator>
+    
+    <%= @inner %>
+  </channel>
+</rss>

apps/mebe_web/web/views/feed_view.ex

@@ -0,0 +1,3 @@
+defmodule MebeWeb.FeedView do
+  use MebeWeb.Web, :view
+end