Current section

Files

Jump to
phoenix lib phoenix socket handler.ex
Raw

lib/phoenix/socket/handler.ex

defmodule Phoenix.Socket.Handler do
@behaviour :cowboy_websocket_handler
alias Phoenix.Socket
alias Phoenix.Socket.Message
alias Phoenix.Channel
defmodule InvalidReturn do
defexception [:message]
def exception(msg) do
%InvalidReturn{message: "Invalid Handler return: #{inspect msg}"}
end
end
def init({:tcp, :http}, req, opts) do
{:upgrade, :protocol, :cowboy_websocket, req, opts}
end
def init({:ssl, :http}, req, opts) do
{:upgrade, :protocol, :cowboy_websocket, req, opts}
end
@doc """
Handles initalization of the websocket
Possible returns:
:ok
{:ok, req, state}
{:ok, req, state, timeout} # Timeout defines how long it waits for activity
from the client. Default: infinity.
"""
def websocket_init(_transport, req, opts) do
router = Dict.fetch! opts, :router
{:ok, req, %Socket{conn: req, pid: self, router: router}}
end
@doc """
Dispatches multiplexed socket message to Router and handles result
# Join Event
"join" events are specially treated.
When {:ok, socket} is returned from the Channel, the socket is subscribed
to the channel and authorized to pubsub on the channel/topic pair
When {:error, socket, reason} is returned, the socket is denied pubsub access
# Leave Event
"leave" events call the channels `leave/2` function only if the socket has
previously been authorized via `join/2`
# Arbitrary Events
Any other event calls the channel's `event/3` function, with the event
name as the first argument. Event handlers are only invoked if the socket
was previously authorized via `join/2`.
"""
def websocket_handle({:text, text}, _req, socket) do
msg = Message.parse!(text)
socket
|> Socket.set_current_channel(msg.channel, msg.topic)
|> dispatch(msg.event, msg.message)
end
defp dispatch(socket, "join", msg) do
socket
|> socket.router.match(:websocket, socket.channel, "join", msg)
|> handle_result("join")
end
defp dispatch(socket, event, msg) do
if Socket.authenticated?(socket, socket.channel, socket.topic) do
socket
|> socket.router.match(:websocket, socket.channel, event, msg)
|> handle_result(event)
else
handle_result({:error, socket, :unauthenticated}, event)
end
end
defp handle_result({:ok, socket}, "join") do
{:ok, socket.conn, Channel.subscribe(socket, socket.channel, socket.topic)}
end
defp handle_result(socket = %Socket{}, "leave") do
{:ok, socket.conn, Channel.unsubscribe(socket, socket.channel, socket.topic)}
end
defp handle_result(socket = %Socket{}, _event) do
{:ok, socket.conn, socket}
end
defp handle_result({:error, socket, _reason}, _event) do
{:ok, socket.conn, socket}
end
defp handle_result(bad_return, event) when event in ["join", "leave"] do
raise InvalidReturn, message: """
expected {:ok, %Socket{}} | {:error, %Socket{}, reason} got #{inspect bad_return}
"""
end
defp handle_result(bad_return, _event) do
raise InvalidReturn, message: """
expected %Socket{} got #{inspect bad_return}
"""
end
@doc """
Handles recieving messages from processes
"""
def info(_info, _req, state) do
{:ok, state}
end
def websocket_info({:reply, frame}, req, state) do
{:reply, frame, req, state}
end
def websocket_info(:shutdown, req, state) do
{:shutdown, req, state}
end
def websocket_info(:hibernate, req, state) do
{:ok, req, state, :hibernate}
end
def websocket_info(data, req, socket) do
Enum.each socket.channels, fn {channel, topic} ->
socket
|> Socket.set_current_channel(channel, topic)
|> socket.router.match(:websocket, channel, "info", data)
|> handle_result("info")
end
{:ok, req, socket}
end
@doc """
This is called right before the websocket is about to be closed.
Reason is defined as:
{:normal, :shutdown | :timeout} Called when erlang closes connection
{:remote, :closed} Called if client formally closes connection
{:remote, close_code(), binary()}
{:error, :badencoding | :badframe | :closed | atom()} Called for many reasons
tab closed, conn dropped.
"""
def websocket_terminate(reason, _req, socket) do
Enum.each socket.channels, fn {channel, topic} ->
socket
|> Socket.set_current_channel(channel, topic)
|> socket.router.match(:websocket, channel, "leave", reason: reason)
|> handle_result("leave")
end
:ok
end
@doc """
Sends a reply to the socket. Follow the cowboy websocket frame syntax
Frame is defined as
:close | :ping | :pong
{:text | :binary | :close | :ping | :pong, iodata()}
{:close, close_code(), iodata()}
Options:
:state
:hibernate # (true | false) if you want to hibernate the connection
close_code: 1000..4999
"""
def reply(socket, frame) do
send(socket.pid, {:reply, frame, socket})
end
@doc """
Terminates a connection.
"""
def terminate(socket) do
send(socket.pid, :shutdown)
end
@doc """
Hibernates the socket.
"""
def hibernate(socket) do
send(socket.pid, :hibernate)
end
end