initial commit

lib/demo.ex

@@ -0,0 +1,9 @@
+defmodule Demo do
+  @moduledoc """
+  Demo keeps the contexts that define your domain
+  and business logic.
+
+  Contexts are also responsible for managing your data, regardless
+  if it comes from the database, an external API or others.
+  """
+end

lib/demo/application.ex

@@ -0,0 +1,36 @@
+defmodule Demo.Application do
+  # See https://hexdocs.pm/elixir/Application.html
+  # for more information on OTP Applications
+  @moduledoc false
+
+  use Application
+
+  @impl true
+  def start(_type, _args) do
+    children = [
+      # Start the Ecto repository
+      Demo.Repo,
+      # Start the Telemetry supervisor
+      DemoWeb.Telemetry,
+      # Start the PubSub system
+      {Phoenix.PubSub, name: Demo.PubSub},
+      # Start the Endpoint (http/https)
+      DemoWeb.Endpoint
+      # Start a worker by calling: Demo.Worker.start_link(arg)
+      # {Demo.Worker, arg}
+    ]
+
+    # See https://hexdocs.pm/elixir/Supervisor.html
+    # for other strategies and supported options
+    opts = [strategy: :one_for_one, name: Demo.Supervisor]
+    Supervisor.start_link(children, opts)
+  end
+
+  # Tell Phoenix to update the endpoint configuration
+  # whenever the application is updated.
+  @impl true
+  def config_change(changed, _new, removed) do
+    DemoWeb.Endpoint.config_change(changed, removed)
+    :ok
+  end
+end

lib/demo/funcs.ex

@@ -0,0 +1,15 @@
+defmodule Funcs do
+
+  # Naive, slow and buggy implementation:
+  def fib(0), do: 0
+  def fib(1), do: 1
+  def fib(n), do: fib(n-1) + fib(n-2)
+
+  # Fast version:
+  #  def fib(n) when not is_number(n) or n < 0, do: raise("arg!")
+  #  def fib(n), do: fib(0, 1, n)
+  #
+  #  def fib(a, b, 0), do: a
+  #  def fib(a, b, n), do: fib(b, a+b, n-1)
+  
+end

lib/demo/funcs.ex~

@@ -0,0 +1,10 @@
+defmodule Funcs do
+
+  def fib(n) when not is_number(n) or n < 0, do: raise("arg!")
+  def fib(n), do: fib(0, 1, n)
+
+  def fib(a, b, 0), do: a
+  def fib(a, b, n), do: fib(b, a+b, n-1)
+  
+  
+end

lib/demo/mailer.ex

@@ -0,0 +1,3 @@
+defmodule Demo.Mailer do
+  use Swoosh.Mailer, otp_app: :demo
+end

lib/demo/repo.ex

@@ -0,0 +1,5 @@
+defmodule Demo.Repo do
+  use Ecto.Repo,
+    otp_app: :demo,
+    adapter: Ecto.Adapters.SQLite3
+end

lib/demo_web.ex

@@ -0,0 +1,102 @@
+defmodule DemoWeb do
+  @moduledoc """
+  The entrypoint for defining your web interface, such
+  as controllers, views, channels and so on.
+
+  This can be used in your application as:
+
+      use DemoWeb, :controller
+      use DemoWeb, :view
+
+  The definitions below will be executed for every view,
+  controller, etc, so keep them short and clean, focused
+  on imports, uses and aliases.
+
+  Do NOT define functions inside the quoted expressions
+  below. Instead, define any helper function in modules
+  and import those modules here.
+  """
+
+  def controller do
+    quote do
+      use Phoenix.Controller, namespace: DemoWeb
+
+      import Plug.Conn
+      import DemoWeb.Gettext
+      alias DemoWeb.Router.Helpers, as: Routes
+    end
+  end
+
+  def view do
+    quote do
+      use Phoenix.View,
+        root: "lib/demo_web/templates",
+        namespace: DemoWeb
+
+      # Import convenience functions from controllers
+      import Phoenix.Controller,
+        only: [get_flash: 1, get_flash: 2, view_module: 1, view_template: 1]
+
+      # Include shared imports and aliases for views
+      unquote(view_helpers())
+    end
+  end
+
+  def live_view do
+    quote do
+      use Phoenix.LiveView,
+        layout: {DemoWeb.LayoutView, "live.html"}
+
+      unquote(view_helpers())
+    end
+  end
+
+  def live_component do
+    quote do
+      use Phoenix.LiveComponent
+
+      unquote(view_helpers())
+    end
+  end
+
+  def router do
+    quote do
+      use Phoenix.Router
+
+      import Plug.Conn
+      import Phoenix.Controller
+      import Phoenix.LiveView.Router
+    end
+  end
+
+  def channel do
+    quote do
+      use Phoenix.Channel
+      import DemoWeb.Gettext
+    end
+  end
+
+  defp view_helpers do
+    quote do
+      # Use all HTML functionality (forms, tags, etc)
+      use Phoenix.HTML
+
+      # Import LiveView and .heex helpers (live_render, live_patch, <.form>, etc)
+      import Phoenix.LiveView.Helpers
+
+      # Import basic rendering functionality (render, render_layout, etc)
+      import Phoenix.View
+
+      import DemoWeb.ErrorHelpers
+      import DemoWeb.Gettext
+      alias DemoWeb.Router.Helpers, as: Routes
+    end
+  end
+
+  @doc """
+  When used, dispatch to the appropriate controller/view/etc.
+  """
+  defmacro __using__(which) when is_atom(which) do
+    apply(__MODULE__, which, [])
+  end
+end

lib/demo_web/channels/room_channel.ex

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+defmodule DemoWeb.RoomChannel do
+  use DemoWeb, :channel
+  require Logger
+  
+  @impl true
+  def join("room:lobby", payload, socket) do
+    if authorized?(payload) do
+      {:ok, socket}
+    else
+      {:error, %{reason: "unauthorized"}}
+    end
+  end
+
+  # Channels can be used in a request/response fashion
+  # by sending replies to requests from the client
+  @impl true
+  def handle_in("ping", payload, socket) do
+    {:reply, {:ok, payload}, socket}
+  end
+
+  #
+  # Here is recieved the requests from the client
+  # we spawn a new process to compute the result, which
+  # is sent back in a new message when the task is finished
+  # The new process PID is used as a key for the client to
+  # associate the result to its request.
+  # the key(id) is immediatly returned to the client.
+  #
+  @impl true
+  def handle_in("fib", payload, socket) do
+    me = self()
+    id = spawn(fn ->
+      result = Funcs.fib(String.to_integer(payload["query"]))
+      send(me, {:response, %{id: Kernel.inspect(self()),
+			     query: payload["query"],
+			     result: result}})
+    end)
+    {:reply, {:ok, %{id: Kernel.inspect(id)}}, socket}
+  end
+  
+  # It is also common to receive messages from the client and
+  # broadcast to everyone in the current topic (room:lobby).
+  @impl true
+  def handle_in("shout", payload, socket) do
+    broadcast(socket, "shout", payload)
+    {:noreply, socket}
+  end
+
+  # Add authorization logic here as required.
+  defp authorized?(_payload) do
+    true
+  end
+
+  @impl true
+  def handle_info({:response, map}, socket) do
+    Logger.debug("send response #{Kernel.inspect map}")
+    push(socket, "response", map)
+    {:noreply, socket}
+  end
+
+
+end

lib/demo_web/channels/user_socket.ex

@@ -0,0 +1,41 @@
+defmodule DemoWeb.UserSocket do
+  use Phoenix.Socket
+
+  # A Socket handler
+  #
+  # It's possible to control the websocket connection and
+  # assign values that can be accessed by your channel topics.
+
+  ## Channels
+
+  channel "room:*", DemoWeb.RoomChannel
+
+  # Socket params are passed from the client and can
+  # be used to verify and authenticate a user. After
+  # verification, you can put default assigns into
+  # the socket that will be set for all channels, ie
+  #
+  #     {:ok, assign(socket, :user_id, verified_user_id)}
+  #
+  # To deny connection, return `:error`.
+  #
+  # See `Phoenix.Token` documentation for examples in
+  # performing token verification on connect.
+  @impl true
+  def connect(_params, socket, _connect_info) do
+    {:ok, socket}
+  end
+
+  # Socket id's are topics that allow you to identify all sockets for a given user:
+  #
+  #     def id(socket), do: "user_socket:#{socket.assigns.user_id}"
+  #
+  # Would allow you to broadcast a "disconnect" event and terminate
+  # all active sockets and channels for a given user:
+  #
+  #     Elixir.DemoWeb.Endpoint.broadcast("user_socket:#{user.id}", "disconnect", %{})
+  #
+  # Returning `nil` makes this socket anonymous.
+  @impl true
+  def id(_socket), do: nil
+end

lib/demo_web/controllers/page_controller.ex

@@ -0,0 +1,7 @@
+defmodule DemoWeb.PageController do
+  use DemoWeb, :controller
+
+  def index(conn, _params) do
+    render(conn, "index.html")
+  end
+end

lib/demo_web/endpoint.ex

@@ -0,0 +1,55 @@
+defmodule DemoWeb.Endpoint do
+  use Phoenix.Endpoint, otp_app: :demo
+
+  # The session will be stored in the cookie and signed,
+  # this means its contents can be read but not tampered with.
+  # Set :encryption_salt if you would also like to encrypt it.
+  @session_options [
+    store: :cookie,
+    key: "_demo_key",
+    signing_salt: "AZgmTvLs"
+  ]
+
+  socket "/live", Phoenix.LiveView.Socket, websocket: [connect_info: [session: @session_options]]
+
+  # Serve at "/" the static files from "priv/static" directory.
+  #
+  # You should set gzip to true if you are running phx.digest
+  # when deploying your static files in production.
+  plug Plug.Static,
+    at: "/",
+    from: :demo,
+    gzip: false,
+    only: ~w(assets fonts images favicon.ico robots.txt)
+
+  # Code reloading can be explicitly enabled under the
+  # :code_reloader configuration of your endpoint.
+  if code_reloading? do
+    socket "/phoenix/live_reload/socket", Phoenix.LiveReloader.Socket
+    plug Phoenix.LiveReloader
+    plug Phoenix.CodeReloader
+    plug Phoenix.Ecto.CheckRepoStatus, otp_app: :demo
+  end
+
+  plug Phoenix.LiveDashboard.RequestLogger,
+    param_key: "request_logger",
+    cookie_key: "request_logger"
+
+  plug Plug.RequestId
+  plug Plug.Telemetry, event_prefix: [:phoenix, :endpoint]
+
+  plug Plug.Parsers,
+    parsers: [:urlencoded, :multipart, :json],
+    pass: ["*/*"],
+    json_decoder: Phoenix.json_library()
+
+  plug Plug.MethodOverride
+  plug Plug.Head
+  plug Plug.Session, @session_options
+  plug DemoWeb.Router
+
+  socket "/socket", DemoWeb.UserSocket,
+    websocket: true,
+    longpoll: false
+  
+end

lib/demo_web/gettext.ex

@@ -0,0 +1,24 @@
+defmodule DemoWeb.Gettext do
+  @moduledoc """
+  A module providing Internationalization with a gettext-based API.
+
+  By using [Gettext](https://hexdocs.pm/gettext),
+  your module gains a set of macros for translations, for example:
+
+      import DemoWeb.Gettext
+
+      # Simple translation
+      gettext("Here is the string to translate")
+
+      # Plural translation
+      ngettext("Here is the string to translate",
+               "Here are the strings to translate",
+               3)
+
+      # Domain-based translation
+      dgettext("errors", "Here is the error message to translate")
+
+  See the [Gettext Docs](https://hexdocs.pm/gettext) for detailed usage.
+  """
+  use Gettext, otp_app: :demo
+end

lib/demo_web/router.ex

@@ -0,0 +1,55 @@
+defmodule DemoWeb.Router do
+  use DemoWeb, :router
+
+  pipeline :browser do
+    plug :accepts, ["html"]
+    plug :fetch_session
+    plug :fetch_live_flash
+    plug :put_root_layout, {DemoWeb.LayoutView, :root}
+    plug :protect_from_forgery
+    plug :put_secure_browser_headers
+  end
+
+  pipeline :api do
+    plug :accepts, ["json"]
+  end
+
+  scope "/", DemoWeb do
+    pipe_through :browser
+
+    get "/", PageController, :index
+  end
+
+  # Other scopes may use custom stacks.
+  # scope "/api", DemoWeb do
+  #   pipe_through :api
+  # end
+
+  # Enables LiveDashboard only for development
+  #
+  # If you want to use the LiveDashboard in production, you should put
+  # it behind authentication and allow only admins to access it.
+  # If your application does not have an admins-only section yet,
+  # you can use Plug.BasicAuth to set up some basic authentication
+  # as long as you are also using SSL (which you should anyway).
+  if Mix.env() in [:dev, :test] do
+    import Phoenix.LiveDashboard.Router
+
+    scope "/" do
+      pipe_through :browser
+      live_dashboard "/dashboard", metrics: DemoWeb.Telemetry
+    end
+  end
+
+  # Enables the Swoosh mailbox preview in development.
+  #
+  # Note that preview only shows emails that were sent by the same
+  # node running the Phoenix server.
+  if Mix.env() == :dev do
+    scope "/dev" do
+      pipe_through :browser
+
+      forward "/mailbox", Plug.Swoosh.MailboxPreview
+    end
+  end
+end

lib/demo_web/telemetry.ex

@@ -0,0 +1,71 @@
+defmodule DemoWeb.Telemetry do
+  use Supervisor
+  import Telemetry.Metrics
+
+  def start_link(arg) do
+    Supervisor.start_link(__MODULE__, arg, name: __MODULE__)
+  end
+
+  @impl true
+  def init(_arg) do
+    children = [
+      # Telemetry poller will execute the given period measurements
+      # every 10_000ms. Learn more here: https://hexdocs.pm/telemetry_metrics
+      {:telemetry_poller, measurements: periodic_measurements(), period: 10_000}
+      # Add reporters as children of your supervision tree.
+      # {Telemetry.Metrics.ConsoleReporter, metrics: metrics()}
+    ]
+
+    Supervisor.init(children, strategy: :one_for_one)
+  end
+
+  def metrics do
+    [
+      # Phoenix Metrics
+      summary("phoenix.endpoint.stop.duration",
+        unit: {:native, :millisecond}
+      ),
+      summary("phoenix.router_dispatch.stop.duration",
+        tags: [:route],
+        unit: {:native, :millisecond}
+      ),
+
+      # Database Metrics
+      summary("demo.repo.query.total_time",
+        unit: {:native, :millisecond},
+        description: "The sum of the other measurements"
+      ),
+      summary("demo.repo.query.decode_time",
+        unit: {:native, :millisecond},
+        description: "The time spent decoding the data received from the database"
+      ),
+      summary("demo.repo.query.query_time",
+        unit: {:native, :millisecond},
+        description: "The time spent executing the query"
+      ),
+      summary("demo.repo.query.queue_time",
+        unit: {:native, :millisecond},
+        description: "The time spent waiting for a database connection"
+      ),
+      summary("demo.repo.query.idle_time",
+        unit: {:native, :millisecond},
+        description:
+          "The time the connection spent waiting before being checked out for the query"
+      ),
+
+      # VM Metrics
+      summary("vm.memory.total", unit: {:byte, :kilobyte}),
+      summary("vm.total_run_queue_lengths.total"),
+      summary("vm.total_run_queue_lengths.cpu"),
+      summary("vm.total_run_queue_lengths.io")
+    ]
+  end
+
+  defp periodic_measurements do
+    [
+      # A module, function and arguments to be invoked periodically.
+      # This function must call :telemetry.execute/3 and a metric must be added above.
+      # {DemoWeb, :count_users, []}
+    ]
+  end
+end

lib/demo_web/templates/layout/app.html.heex

@@ -0,0 +1,5 @@
+<main class="container">
+  <p class="alert alert-info" role="alert"><%= get_flash(@conn, :info) %></p>
+  <p class="alert alert-danger" role="alert"><%= get_flash(@conn, :error) %></p>
+  <%= @inner_content %>
+</main>

lib/demo_web/templates/layout/live.html.heex

@@ -0,0 +1,11 @@
+<main class="container">
+  <p class="alert alert-info" role="alert"
+    phx-click="lv:clear-flash"
+    phx-value-key="info"><%= live_flash(@flash, :info) %></p>
+
+  <p class="alert alert-danger" role="alert"
+    phx-click="lv:clear-flash"
+    phx-value-key="error"><%= live_flash(@flash, :error) %></p>
+
+  <%= @inner_content %>
+</main>

lib/demo_web/templates/layout/root.html.heex

@@ -0,0 +1,30 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8"/>
+    <meta http-equiv="X-UA-Compatible" content="IE=edge"/>
+    <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
+    <%= csrf_meta_tag() %>
+    <%= live_title_tag assigns[:page_title] || "Demo", suffix: " · Phoenix Framework" %>
+    <link phx-track-static rel="stylesheet" href={Routes.static_path(@conn, "/assets/app.css")}/>
+    <script defer phx-track-static type="text/javascript" src={Routes.static_path(@conn, "/assets/app.js")}></script>
+  </head>
+  <body>
+    <header>
+      <section class="container">
+        <nav>
+          <ul>
+            <li><a href="https://hexdocs.pm/phoenix/overview.html">Get Started</a></li>
+            <%= if function_exported?(Routes, :live_dashboard_path, 2) do %>
+              <li><%= link "LiveDashboard", to: Routes.live_dashboard_path(@conn, :home) %></li>
+            <% end %>
+          </ul>
+        </nav>
+        <a href="https://phoenixframework.org/" class="phx-logo">
+          <img src={Routes.static_path(@conn, "/images/phoenix.png")} alt="Phoenix Framework Logo"/>
+        </a>
+      </section>
+    </header>
+    <%= @inner_content %>
+  </body>
+</html>

lib/demo_web/templates/page/index.html.heex

@@ -0,0 +1,13 @@
+<section class="phx-hero">
+  <h1>Stats</h1>
+  <canvas style="width=800px" id="ping_canvas" width="400" height="200"></canvas>
+</section>
+
+<section class="row">
+  <article class="column">
+    <h2>Fib</h2>
+    <input id="in_fib" /><input id="btn_fib" type="button" value="Send"/>
+    <div id="results">
+    </div>
+  </article>
+</section>

lib/demo_web/templates/page/index.html.heex~

@@ -0,0 +1,41 @@
+<section class="phx-hero">
+  <h1><%= gettext "Welcome to %{name}!", name: "Phoenix" %></h1>
+  <p>Peace of mind from prototype to production</p>
+</section>
+
+<section class="row">
+  <article class="column">
+    <h2>Resources</h2>
+    <ul>
+      <li>
+        <a href="https://hexdocs.pm/phoenix/overview.html">Guides &amp; Docs</a>
+      </li>
+      <li>
+        <a href="https://github.com/phoenixframework/phoenix">Source</a>
+      </li>
+      <li>
+        <a href="https://github.com/phoenixframework/phoenix/blob/v1.6/CHANGELOG.md">v1.6 Changelog</a>
+      </li>
+    </ul>
+  </article>
+  <article class="column">
+    <h2>Help</h2>
+    <ul>
+      <li>
+        <a href="https://elixirforum.com/c/phoenix-forum">Forum</a>
+      </li>
+      <li>
+        <a href="https://web.libera.chat/#elixir">#elixir on Libera Chat (IRC)</a>
+      </li>
+      <li>
+        <a href="https://twitter.com/elixirphoenix">Twitter @elixirphoenix</a>
+      </li>
+      <li>
+        <a href="https://elixir-slackin.herokuapp.com/">Elixir on Slack</a>
+      </li>
+      <li>
+        <a href="https://discord.gg/elixir">Elixir on Discord</a>
+      </li>
+    </ul>
+  </article>
+</section>

lib/demo_web/views/error_helpers.ex

@@ -0,0 +1,47 @@
+defmodule DemoWeb.ErrorHelpers do
+  @moduledoc """
+  Conveniences for translating and building error messages.
+  """
+
+  use Phoenix.HTML
+
+  @doc """
+  Generates tag for inlined form input errors.
+  """
+  def error_tag(form, field) do
+    Enum.map(Keyword.get_values(form.errors, field), fn error ->
+      content_tag(:span, translate_error(error),
+        class: "invalid-feedback",
+        phx_feedback_for: input_name(form, field)
+      )
+    end)
+  end
+
+  @doc """
+  Translates an error message using gettext.
+  """
+  def translate_error({msg, opts}) do
+    # When using gettext, we typically pass the strings we want
+    # to translate as a static argument:
+    #
+    #     # Translate "is invalid" in the "errors" domain
+    #     dgettext("errors", "is invalid")
+    #
+    #     # Translate the number of files with plural rules
+    #     dngettext("errors", "1 file", "%{count} files", count)
+    #
+    # Because the error messages we show in our forms and APIs
+    # are defined inside Ecto, we need to translate them dynamically.
+    # This requires us to call the Gettext module passing our gettext
+    # backend as first argument.
+    #
+    # Note we use the "errors" domain, which means translations
+    # should be written to the errors.po file. The :count option is
+    # set by Ecto and indicates we should also apply plural rules.
+    if count = opts[:count] do
+      Gettext.dngettext(DemoWeb.Gettext, "errors", msg, msg, count, opts)
+    else
+      Gettext.dgettext(DemoWeb.Gettext, "errors", msg, opts)
+    end
+  end
+end

lib/demo_web/views/error_view.ex

@@ -0,0 +1,16 @@
+defmodule DemoWeb.ErrorView do
+  use DemoWeb, :view
+
+  # If you want to customize a particular status code
+  # for a certain format, you may uncomment below.
+  # def render("500.html", _assigns) do
+  #   "Internal Server Error"
+  # end
+
+  # By default, Phoenix returns the status message from
+  # the template name. For example, "404.html" becomes
+  # "Not Found".
+  def template_not_found(template, _assigns) do
+    Phoenix.Controller.status_message_from_template(template)
+  end
+end

lib/demo_web/views/layout_view.ex

@@ -0,0 +1,7 @@
+defmodule DemoWeb.LayoutView do
+  use DemoWeb, :view
+
+  # Phoenix LiveDashboard is available only in development by default,
+  # so we instruct Elixir to not warn if the dashboard route is missing.
+  @compile {:no_warn_undefined, {Routes, :live_dashboard_path, 2}}
+end

lib/demo_web/views/page_view.ex

@@ -0,0 +1,3 @@
+defmodule DemoWeb.PageView do
+  use DemoWeb, :view
+end