GenServer in elixir delaying task - erlang

Question

I am trying to show a post to the first friend of a person first and other's after making a delay of 1 min. For that I am using GenServer.
The problem is that the first friend as well as the other friends are getting the post after 1 min.
Here is my code of GenServer:
defmodule Phoenix.SchedulePost do
use GenServer
def start_link(state) do
GenServer.start_link(__MODULE__, state)
end
def init(state) do
schedule_post(state)
{:ok, state}
end
# handling looby
def handle_info(:postSchedule, state) do
#sending posts to others
{:noreply, state}
end
# scheduling a task
defp schedule_post(state) do
IO.puts "scheduling the task"
Process.send_after(self(), :postSchedule, 60*1000)
end
end
I am starting a GenServer process for each post request and sending it to the first friend. Here is the code:
def handle_in("post:toFrstFrnd", %{"friendId"=>friendId,"body" => body}, socket) do
newSocket = PhoenixWeb.SocketBucket.get_socket(friendId)
if newSocket != nil do
push newSocket, "post:toFrstFrnd", %{"friendId": friendId,"body": body}
end
Phoenix.SchedulePost.start_link(postId)
{:noreply, socket}
end
Help me out, thank you in advance.

Answer 1

Note: I know it's a rather old question, but maybe someone else has a similar problem and ends up here.
I think you want to trigger an action initially and then another action a minute later. The problem with your code is that you call the schedule_post method in your init method and it does nothing for a minute. After one minute you send a message to the process itself, whereupon handle_info method takes over. But now it is already much too late for the initial action.
Here is an example how you could do it:
defmodule Phoenix.SchedulePost do
use GenServer
def start_link(state \\ []) do
GenServer.start_link(__MODULE__, state)
end
def init(state) do
send(self(), :first_action)
{:ok, state}
end
def handle_info(:first_action, state) do
IO.puts("Called immediately")
# Do something here...
Process.send_after(self(), :second_action, 60 * 1000)
{:noreply, state}
end
def handle_info(:second_action, state) do
IO.puts "Called after 1 min"
# Do something here...
{:noreply, state}
end
end
But keep in mind that the process will continue to live even after the second action is done. It will not terminate automatically, you have to take care of that.