Add feature to customize menu links via a menu file

README.md

@@ -14,6 +14,7 @@ The engine consists of two parts:
 * `git clone`
 * Copy `config/*.exs.dist`, removing the `.dist` ending and go through the configs.
 * `npm install && gulp` to build the frontend.
+* Put some content into the data path you specified, at least a `menu` file.
 * `mix phoenix.server` to run the development server.
 
 ## Features

lib/mebe_engine/db.ex

@@ -4,19 +4,22 @@ defmodule MebeEngine.DB do
   """
 
   # Table for meta information, like the counts of posts
-  @meta_table :meta
+  @meta_table :mebeweb_meta
 
   # Table for storing pages by slug
-  @page_table :pages
+  @page_table :mebeweb_pages
 
   # Table for sequential retrieval of posts (for list pages)
-  @post_table :posts
+  @post_table :mebeweb_posts
 
   # Table for quick retrieval of single post (with key)
-  @single_post_table :single_posts
+  @single_post_table :mebeweb_single_posts
 
   # Table for storing posts with tag as first element of key
-  @tag_table :tags
+  @tag_table :mebeweb_tags
+
+  # Table for storing menu data
+  @menu_table :mebeweb_menu
 
   def init() do
     # Only create tables if they don't exist already
@@ -26,6 +29,7 @@ defmodule MebeEngine.DB do
       :ets.new @post_table,         [:named_table, :ordered_set,  :protected, read_concurrency: true]
       :ets.new @single_post_table,  [:named_table, :set,          :protected, read_concurrency: true]
       :ets.new @tag_table,          [:named_table, :ordered_set,  :protected, read_concurrency: true]
+      :ets.new @menu_table,         [:named_table, :ordered_set,  :protected, read_concurrency: true]
     end
   end
 
@@ -41,6 +45,12 @@ defmodule MebeEngine.DB do
     :ets.insert @meta_table, {key, count}
   end
 
+  def insert_menu(menu) do
+    # Format for ETS because it needs a tuple
+    menu = Enum.map menu, fn menuitem -> {menuitem.slug, menuitem} end
+    :ets.insert @menu_table, menu
+  end
+
   def insert_posts(posts) do
     ordered_posts = Enum.map posts, fn post ->
       {year, month, day} = post.date
@@ -66,6 +76,13 @@ defmodule MebeEngine.DB do
   end
 
 
+  def get_menu() do
+    case :ets.match @menu_table, :"$1" do
+      [] -> []
+      results -> format_menu results
+    end
+  end
+
   def get_reg_posts(first, last) do
     get_post_list @post_table, [{:"$1", [], [:"$_"]}], first, last
   end
@@ -121,4 +138,9 @@ defmodule MebeEngine.DB do
   defp ets_to_data(data) do
     Enum.map data, fn {_, actual} -> actual end
   end
+
+  # Format menu results (convert [{slug, %MenuItem{}}] to %MenuItem{})
+  defp format_menu(results) do
+    for [{_, result}] <- results, do: result
+  end
 end

lib/mebe_engine/menuparser.ex

@@ -0,0 +1,29 @@
+defmodule MebeEngine.MenuParser do
+  @moduledoc """
+  This module handles the parsing of the menu file, which lists the links in the menu bar.
+  """
+  alias MebeEngine.Models.MenuItem
+
+  def parse(data_path) do
+    (data_path <> "/menu")
+    |> File.read!
+    |> split_lines
+    |> parse_lines
+
+    # Filter out nils that come from badly formatted lines
+    |> Enum.filter(fn item -> item != nil end)
+  end
+
+  defp split_lines(menudata) do
+    String.split menudata, ~R/\r?\n/
+  end
+
+  defp parse_lines(menulines) do
+    for line <- menulines do
+      case String.split line, " " do
+        [_] -> nil
+        [link | rest] -> %MenuItem{slug: link, title: Enum.join(rest, " ")}
+      end
+    end
+  end
+end

lib/mebe_engine/models.ex

@@ -26,4 +26,9 @@ defmodule MebeEngine.Models do
       title: nil,
       content: nil
   end
+
+  defmodule MenuItem do
+    defstruct slug: nil,
+      title: nil
+  end
 end

lib/mebe_engine/worker.ex

@@ -7,6 +7,7 @@ defmodule MebeEngine.Worker do
 
   alias MebeEngine.Crawler
   alias MebeEngine.DB
+  alias MebeEngine.MenuParser
   alias MebeWeb.Utils
 
   def start_link(opts \\ []) do
@@ -37,6 +38,10 @@ defmodule MebeEngine.Worker do
   def load_db() do
     data_path = Utils.get_conf :data_path
 
+    Logger.info "Loading menu from '#{data_path}/menu'…"
+
+    menu = MenuParser.parse data_path
+
     Logger.info "Loading post database from '#{data_path}'…"
 
     %{
@@ -51,6 +56,7 @@ defmodule MebeEngine.Worker do
 
     DB.init
 
+    DB.insert_menu menu
     DB.insert_posts posts
     DB.insert_count :all, Enum.count posts
 

web/controllers/page_controller.ex

@@ -5,6 +5,8 @@ defmodule MebeWeb.PageController do
   alias MebeWeb.Utils
   import MebeWeb.ControllerUtils, only: [render_posts: 4, insert_config: 1, render_404: 1]
 
+  plug :assign_menu
+
   def index(conn, params) do
     conn
     |> render_page(
@@ -159,4 +161,10 @@ defmodule MebeWeb.PageController do
       posts_per_page
     }
   end
+
+  # Get menu from ETS and assign it to every page's data
+  defp assign_menu(conn, _opts) do
+    conn
+    |> assign(:menu, DB.get_menu)
+  end
 end

web/templates/layout/app.html.eex

@@ -28,7 +28,12 @@
         </div>
 
         <ul class="nav navbar-nav">
-          <li><a href="<%= page_path @conn, :page, "about" %>">About</a></li>
+
+          <%= for menuitem <- @menu do %>
+            <li>
+              <a href="<%= menuitem.slug %>"><%= menuitem.title %></a>
+            </li>
+          <% end %>
         </ul>
       </div>
     </div>