Question

it’s continue of previos question

I have gen_server:

start(UserName) ->
    case gen_server:start({global, UserName}, player, [], []) of
    {ok, _} ->
        io:format("Player: " ++ UserName ++ " started");
    {error, Error} ->
        Error
    end
    ...

How correctly send message to this gen_server. For example: in another file i make:

gen_server:cast(test, message).

In my gen_server file i have:

handle_cast(message, State) ->
    io:format("Message receiving \r\n"),
    {noreply, State};

I start my gen_server with test name:

server:start(test).
test started

when i call gen_server:cast(test, message). it is nothing output in shell. How can i check handle_cast calling or not?

Thank you.

Answer 1

Instead of

gen_server:cast(test, message).

write

gen_server:cast({global, test}, message).

If you register name as {global, name} you must call it as {global, name}

If your handler is called it will print “Message receiving \r\n” in shell. You made that with io:format call.