CODEWITHSUNDEEP
elixirphoenix-framework
quantumpotato
quantumpotato

Reputation: 9767

Undefined function send/3

I am trying to listen for a message in my socket router, send a message to an in-memory process, a spawned Runner module, then broadcast a result to the client.

Outside of Phoenix in a standalone test, this code works. With Phoenix, I get this error

~/chatroom:.mix phoenix.server
Compiling 2 files (.ex)

== Compilation error on file web/models/runner.ex ==
** (CompileError) web/models/runner.ex:8: undefined function send/3
    (stdlib) lists.erl:1338: :lists.foreach/2
    (stdlib) erl_eval.erl:670: :erl_eval.do_apply/6
    (elixir) lib/kernel/parallel_compiler.ex:117: anonymous fn/4 in Kernel.ParallelCompiler.spawn_compilers/1

My lobby_channel.ex:

defmodule Chatroom.LobbyChannel do
  require Runner
  use Phoenix.Channel

  {:ok, pid: spawn(fn -> Runner.input() end)}

  def join("lobby", _payload, socket) do
    {:ok, socket}
  end

  def handle_in("new_message", payload, socket) do
    case payload["message"] do
      "hello" -> broadcast! socket, "new_message", payload
      "jump" -> send pid, {:jump, self, [avatar: avatar, socket: socket]}
      _ -> nil
    end

    {:noreply, socket}
  end

  receive do
    {:result, mover, socket} -> broadcast! socket, "new_message", [name: "State", message: "5"]
  end
end

Runner.ex, stored in web/models/runner.ex

defmodule Runner do
    def spawn do
        %{maxJump: 100}
    end

    def input do
      receive do
       {:run, sender, data} -> send sender, run(sender[:avatar]), data[:socket]
       {:jump, sender, data} -> send sender, jump(sender[:avatar]), data[:socket]
     end

     input
    end

    defp run(mover) do
      mover = case mover.y do 
        1 ->
          Map.merge(mover, %{y: 0})
        _ -> mover
      end

        Map.merge(mover, %{x: mover.x + 1})
    end

    defp jump(mover) do
        case {mover.y} do
          {0} ->
            Map.merge(mover, %{y: mover.y + 1})
          _ ->
            mover
        end
    end
end

Why can I not send these messages?

Upvotes: 0

Views: 713

Answers (1)

legoscia
legoscia

Reputation: 41598

The error occurs in this expression, which calls the function send with three arguments:

send sender, run(sender[:avatar]), data[:socket]

But the send function only accepts two arguments: the process to send something to, and the message to send. Perhaps you wanted to embed those two items in a tuple? Like this:

send sender, {run(sender[:avatar]), data[:socket]}

There is a send function which takes three arguments, namely Process.send/3. Its third argument is a list of options. You have to specify the module name explicitly to call it.

Upvotes: 2

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