CODEWITHSUNDEEP
elixirphoenix-framework
code.cycling
code.cycling

Reputation: 1274

How to trigger channel broadcast in the controller in Phoenix

I'm trying to figure out on how to trigger the channel broadcast from the controller.

Example

def create(conn, %{"message" => message_params}) do
with {:ok, %Message{} = message} <- Chat.create_message(message_params) do
  conn

  # TRIGGER CHANNEL BROADCAST "SHOUT" HERE

  |> put_status(:created)
  |> put_resp_header("location", message_path(conn, :show, message))
  |> render("show.json", message: message)
end end

water_cooler channel

defmodule NotificationWeb.WaterCoolerChannel do
 use NotificationWeb, :channel
 def join("water_cooler:lobby", _payload, socket) do
  {:ok, socket}
 end
 def handle_in("shout", payload, socket) do
 broadcast socket, "shout", payload
  {:noreply, socket}
 end
end

I've tried to use NotificationWeb.broadcast(topic, event, msg) but confused on what to put in

topic = "water_cooler" ?

event = ?

message = ?

Upvotes: 0

Views: 694

Answers (1)

Igor Drozdov
Igor Drozdov

Reputation: 15045

It's possible to broadcast a message using broadcast function of the NotificationWeb.Endpoint.

  • topic here is the room, in which you want to broadcast (for example water_cooler:lobby)

  • event is the name of the event, you're expecting to receive on the client

  • msg is the additional information within the event

Considering you have something like this on the front-end part:

channel.on("new_msg", payload => {
  // process new message
})

then event equals new_msg, and msg is the data, which payload variable within this event will contain

Upvotes: 2

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