tasks

using task module, request for sensors

README.md

@@ -46,9 +46,9 @@
 
 22. pragstudio-elixir-21-processes-1 - [Processes 1](https://github.com/skedaddl3/elixir-pragstudio/commit/3b109474f3597d08aff6983599e0576b5786218c)
 
-23. pragstudio-elixir-21-processes-2 - [Processes 2]()
+23. pragstudio-elixir-21-processes-2 - [Processes 2](https://github.com/skedaddl3/elixir-pragstudio/commit/3b109474f3597d08aff6983599e0576b5786218c)
 
-24. pragstudio-elixir-22-messages - [Messages]()
+24. pragstudio-elixir-22-messages - [Messages](https://github.com/skedaddl3/elixir-pragstudio/commit/5430de13ba6b4f9eb004bc10934d398f5a7cdadd)
 
 25. pragstudio-elixir-23-tasks - [Tasks]()
 

lib/fetcher.ex

@@ -0,0 +1,13 @@
+defmodule Servy.Fetcher do
+  def async(fun) do
+    parent = self()
+
+    spawn(fn -> send(parent, {self(), :result, fun.()}) end)
+  end
+
+  def get_result(pid) do
+    receive do
+      {^pid, :result, value} -> value
+    end
+  end
+end

lib/handler.ex

@@ -2,6 +2,8 @@ defmodule Servy.Handler do
   alias Servy.Conv
   alias Servy.BearController
   alias Servy.VideoCam
+  # alias Servy.Fetcher
+
   import Servy.Plugins, only: [rewrite_path: 1, log: 1, track: 1]
   import Servy.Parser, only: [parse: 1]
   @moduledoc "Handles HTTP requests."
@@ -21,35 +23,28 @@ defmodule Servy.Handler do
   #   route(conv, conv.method, conv.path)
   # end
 
-  def route(%Conv{method: "GET", path: "/snapshots"} = conv) do
-    # the request-handling process
-    parent = self()
+  def route(%Conv{method: "GET", path: "/sensors"} = conv) do
+    task = Task.async(fn -> Servy.Tracker.get_location("bigfoot") end)
+
+    snapshots =
+      ["cam-1", "cam-2", "cam-3"]
+      |> Enum.map(&Task.async(fn -> VideoCam.get_snapshot(&1) end))
+      |> Enum.map(&Task.await/1)
 
-    spawn(fn -> send(parent, {:result, VideoCam.get_snapshot("cam-1")}) end)
-    spawn(fn -> send(parent, {:result, VideoCam.get_snapshot("cam-2")}) end)
-    spawn(fn -> send(parent, {:result, VideoCam.get_snapshot("cam-3")}) end)
+    where_is_bigfoot = Task.await(task)
 
-    snapshot1 =
-      receive do
-        {:result, filename} -> filename
-      end
+    # snapshot1 = Fetcher.get_result(pid1)
 
-    snapshot2 =
-      receive do
-        {:result, filename} -> filename
-      end
+    # snapshot2 = Fetcher.get_result(pid2)
 
-    snapshot3 =
-      receive do
-        {:result, filename} -> filename
-      end
+    # snapshot3 = Fetcher.get_result(pid3)
 
     # snapshot2 = VideoCam.get_snapshot("cam-2")
     # snapshot3 = VideoCam.get_snapshot("cam-3")
 
-    snapshots = [snapshot1, snapshot2, snapshot3]
+    # snapshots = [snapshot1, snapshot2, snapshot3]
 
-    %{conv | status: 200, resp_body: inspect(snapshots)}
+    %{conv | status: 200, resp_body: inspect({snapshots, where_is_bigfoot})}
   end
 
   def route(%Conv{method: "GET", path: "/kaboom"}) do

lib/tracker.ex

@@ -0,0 +1,22 @@
+defmodule Servy.Tracker do
+  @doc """
+  Simulates sending a request to an external API
+  to get the GPS coordinates of a wildthing.
+  """
+  def get_location(wildthing) do
+    # CODE GOES HERE TO SEND A REQUEST TO THE EXTERNAL API
+
+    # Sleep to simulate the API delay:
+    :timer.sleep(500)
+
+    # Example responses returned from the API:
+    locations = %{
+      "roscoe" => %{lat: "44.4280 N", lng: "110.5885 W"},
+      "smokey" => %{lat: "48.7596 N", lng: "113.7870 W"},
+      "brutus" => %{lat: "43.7904 N", lng: "110.6818 W"},
+      "bigfoot" => %{lat: "29.0469 N", lng: "98.8667 W"}
+    }
+
+    Map.get(locations, wildthing)
+  end
+end