add elixir language server support

.gitignore

@@ -1,3 +1,6 @@
 *~
 node_modules
 .DS_Store
+_build/
+mix.lock
+deps/

README.md

@@ -44,6 +44,12 @@ cpan Mojolicious
 perl server.pl
 ```
 
+### Elixir
+```elixir
+mix deps.get
+mix run --no-halt
+```
+
 And visit <http://localhost:3000/>. Try opening multiple tabs!
 
 ## Changing the port

lib/reacttutorial.ex

@@ -0,0 +1,22 @@
+defmodule ReactTutorial do
+  def version,  do: unquote(Mix.Project.config[:version])
+  def elixir_version, do: unquote(System.version)
+
+  use Application
+
+  def start( _type, _args ) do
+    import Supervisor.Spec, warn: false
+
+    children = [
+      worker(__MODULE__, [], function: :run)
+    ]
+
+    opts = [strategy: :one_for_one, name: ReactTutorial.Supervisor]
+    Supervisor.start_link(children, opts)
+  end
+
+  def run do
+    { :ok, _ } = Plug.Adapters.Cowboy.http(Server, [], port: 3000)
+  end
+
+end

lib/server.ex

@@ -0,0 +1,101 @@
+defmodule Server do
+  import Plug.Conn
+
+  def init(options) do
+    Hex.Shell.info("Server started: http://localhost:3000/")
+    options
+  end
+
+  def call(conn, _opts) do
+    http_res(conn, conn.request_path)
+  end
+
+  def http_res(conn, uri) do
+    cond do
+      uri =~ ~r"index.html$|^/$|.js$|.css" ->
+        fileName = get_file_name(uri)
+        conn
+        |> put_resp_content_type(get_content_type(conn.request_path))
+        |> send_resp(200, get_file_content(fileName))
+      uri == "/api/comments" ->
+        case conn.method do
+          "POST" ->
+            conn = parse(conn)
+            author = conn.params["author"]
+            text = conn.params["text"]
+            id = conn.params["id"]
+            # Hex.Shell.info("post #{conn.query_string} author:#{author} text:#{text} id:#{id}")
+            fileName = Path.join(root_path(), "comments.json")
+            newComment = %{"author" => author, "id" => id, "text" => text}
+            {:ok, content} = File.read("comments.json")
+            currentComments = Poison.Parser.parse!(content)
+            updatedCommentsJson = List.insert_at(currentComments, -1, newComment)
+            content = Poison.encode!(updatedCommentsJson)
+            File.write(fileName, content)
+            conn
+            |> send_resp(200, "post success")
+          _ ->
+            fileName = Path.join(root_path(), "comments.json")
+            conn
+            |> put_resp_content_type("application/json")
+            |> send_resp(200, get_file_content(fileName))
+        end
+      true ->
+        conn
+        |> send_resp(200, "Hello world")
+    end
+  end
+
+  def parse(conn, opts \\ []) do
+    opts = Keyword.put_new(opts, :parsers, [Plug.Parsers.URLENCODED, Plug.Parsers.MULTIPART])
+    Plug.Parsers.call(conn, Plug.Parsers.init(opts))
+  end
+
+  def get_file_name(uri) do
+    cond do
+      uri =~ ~r"index.html$|^/$" ->
+        Path.join(root_path(), "public/index.html")
+      uri =~ ~r".js$|.css" ->
+        Path.join(root_path(), "public" <> uri)
+      true ->
+        uri
+    end
+  end
+
+  def root_path() do
+    Path.join(__DIR__, "../") |> Path.expand()
+  end
+
+  def get_file_content(file) do
+    case File.read(file) do
+      {:ok, content} ->
+        content
+      {:error, _} ->
+        "404 not find!"
+    end
+  end
+
+  def get_content_type(request_path) do
+    cond do
+      request_path == "/" ->
+        "text/html"
+      request_path =~ ~r".html$|.htm$|.jsp$" ->
+        "text/html"
+      request_path =~ ~r".css$" ->
+        "text/css"
+      request_path =~ ~r".png$" ->
+        "image/png"
+      request_path =~ ~r".ico$" ->
+        "image/x-icon"
+      request_path =~ ~r".gif$" ->
+        "image/gif"
+      request_path =~ ~r".jpe$|.jpeg$" ->
+        "image/jpeg"
+      request_path =~ ~r".jpg$" ->
+        "application/x-jpg"
+      true ->
+        "text/plain"
+    end
+  end
+
+end

mix.exs

@@ -0,0 +1,35 @@
+defmodule Reacttutorial.Mixfile do
+  use Mix.Project
+
+  def project do
+    [app: :reacttutorial,
+     version: "0.0.1",
+     elixir: "~> 1.1",
+     build_embedded: Mix.env == :prod,
+     start_permanent: Mix.env == :prod,
+     deps: deps]
+  end
+
+  # Configuration for the OTP application
+  #
+  # Type "mix help compile.app" for more information
+  def application do
+    [applications: [:logger,:cowboy],
+     mod: {ReactTutorial, []}]
+  end
+
+  # Dependencies can be Hex packages:
+  #
+  #   {:mydep, "~> 0.3.0"}
+  #
+  # Or git/path repositories:
+  #
+  #   {:mydep, git: "https://github.com/elixir-lang/mydep.git", tag: "0.1.0"}
+  #
+  # Type "mix help deps" for more examples and options
+  defp deps do
+    [{:cowboy, "~> 1.0" },
+     {:plug, "~> 0.14" },
+     {:poison, "~> 2.0"}]
+  end
+end