Part2

README.md

@@ -8,4 +8,5 @@ My experience and knowledge about Elixir is very basic. So be prepared to find m
 
 ## Tutorial
 
-### [Part 1 - Basic Setup](./tutorial/part1.md)
+#### [Part 1 - Basic Setup](./tutorial/part1.md)
+#### [Part 2 - The first REST resource (Work in progress)](./tutorial/part2.md)

server/lib/data/article.ex

@@ -0,0 +1,7 @@
+defmodule Data.Article do
+  defstruct [:id ,:href ,:title]
+
+  def from_json_map map do
+    %Data.Article{id: map["id"], href: map["href"], title: map["title"]}
+  end
+end

server/lib/server.ex

@@ -9,7 +9,8 @@ defmodule Server do
     children = [
       # Define workers and child supervisors to be supervised
       # worker(Server.Worker, [arg1, arg2, arg3]),
-      Plug.Adapters.Cowboy.child_spec(:http, Server.Routes, [], port: 8080)
+      Plug.Adapters.Cowboy.child_spec(:http, Server.Routes, [], port: 8080),
+      worker(Storage.Articles, [])
     ]
 
     # See http://elixir-lang.org/docs/stable/elixir/Supervisor.html

server/lib/server/routes.ex

@@ -11,6 +11,8 @@ defmodule Server.Routes do
       |> send_resp(200, Poison.encode!(data))
   end
 
+  forward "/articles", to: Server.Routes.Articles
+
   match _ do
     send_resp(conn, 404, "you shall not pass")
   end

server/lib/server/routes/articles.ex

@@ -0,0 +1,37 @@
+defmodule Server.Routes.Articles do
+  use Plug.Router
+
+  plug Plug.Logger, log: :debug
+  plug Plug.Parsers, parsers: [:json], json_decoder: Poison
+  plug :match
+  plug :dispatch
+
+  get "/" do
+    data = Storage.Articles.list()
+    conn
+      |> set_json_resp
+      |> send_resp(200, Poison.encode!(data))
+  end
+
+  get "/:aid" do
+    data = Storage.Articles.find(aid)
+
+    case data do
+      nil -> conn |> set_json_resp |> send_resp(404, Poison.encode!(%{message: "not found"}))
+      data -> conn |> set_json_resp |> send_resp(200, Poison.encode!(data))
+    end
+  end
+
+  post "/" do
+    new_article = Data.Article.from_json_map(conn.params)
+
+    new_article = Storage.Articles.create(new_article)
+
+    conn
+      |> put_resp_header("Location","/articles/" <> new_article.id)
+      |> send_resp(201,"")
+  end
+
+  defp set_json_resp(conn), do: conn |> put_resp_header("Content-Type","application/json")
+
+end

server/lib/storage/articles.ex

@@ -0,0 +1,67 @@
+defmodule Storage.Articles do
+  use GenServer
+
+  # Interface
+
+  def start_link do
+    articles = [
+      %Data.Article{id: "1", href: "http://example.com/article1", title: "Funny Article"},
+      %Data.Article{id: "2", href: "http://example.com/article2", title: "Important Article"}
+    ]
+    GenServer.start_link(__MODULE__, articles, [name: __MODULE__])
+  end
+
+  def list do
+    GenServer.call(__MODULE__,{:list})
+  end
+
+  def find id do
+    GenServer.call(__MODULE__, {:find, id})
+  end
+
+  def create %Data.Article{} = article do
+    GenServer.call(__MODULE__, {:create, article})
+  end
+
+  # Server
+
+  def init articles do
+    {:ok, articles}
+  end
+
+  def handle_call({:list}, _from, articles) do
+    {:reply, articles, articles}
+  end
+
+  def handle_call({:find, id}, _from, articles) do
+    article = find(articles, id)
+    {:reply, article, articles}
+  end
+
+  def handle_call({:create, article}, _from, articles) do
+    article = %Data.Article{article| id: create_new_id(articles)}
+    {:reply, article, [article| articles]}
+  end
+
+
+  defp find(articles, id) do
+    articles |> Enum.find(fn(article) -> article.id == id end)
+  end
+
+  defp create_new_id(articles) do
+    id = create_random_id()
+
+    case find(articles, id) do
+      nil -> id
+      _ -> create_new_id(articles)
+    end
+  end
+
+  defp create_random_id do
+    alphabet = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+    alphabet_length = String.length(alphabet)
+    0..31 |> Enum.map_join(fn(_) -> 
+      String.at(alphabet, :random.uniform(alphabet_length) - 1)
+    end)
+  end
+end

server/mix.exs

@@ -29,7 +29,7 @@ defmodule Server.Mixfile do
   # Type "mix help deps" for more examples and options
   defp deps do
     [{:cowboy, "~> 1.0.4"},
-     {:plug, "~> 1.1.0"},
-     {:poison, "~> 1.4.0"}]
+     {:plug, "~> 1.1.1"},
+     {:poison, "~> 2.1.0"}]
   end
 end

server/mix.lock

@@ -1,5 +1,5 @@
 %{"cowboy": {:hex, :cowboy, "1.0.4"},
   "cowlib": {:hex, :cowlib, "1.0.2"},
   "plug": {:hex, :plug, "1.1.1"},
-  "poison": {:hex, :poison, "1.4.0"},
+  "poison": {:hex, :poison, "2.1.0"},
   "ranch": {:hex, :ranch, "1.2.1"}}