handle timeout config for apns:connect/1

[dcy]

Hi! When i use apns:connect/1 to open my connections, I must add the timeout config to sys.config:

{apns, [
    {timeout, 10000}
]},

%% for apns:connect/1
{push_confs, [
    #{id => apns1, certfile => "priv/apns1_cert.pem", keyfile => "priv/apns1_key.pem", is_dev_env => false, headers => #{}, timeout => 10000},
    #{id => apns2, certfile => "priv/apns2_cert.pem", keyfile => "priv/apns2_key.pem", is_dev_env => false, headers => #{apns_topic => "net.gzligo.LGTranslator"}, timeout => 10000}
]}

So i think the timeout should save in Connection, not use application:get_env(apns, timeout)(except default_connection).

[elvisci]

Line 342 is too long: -spec push(pid(), apns:device_id(), apns:headers(), notification(), integer()) ->.

[elvisci]

Line 238 is too long: handle_info(timeout, #{connection := Connection, gun_connection := GunConn, client := Client} = State) ->.

[elvisci]

Line 343 is too long: -spec push(pid(), apns:device_id(), apns:headers(), notification(), integer()) ->.

[ferigis]

hi @dcy , thanks for your contribution.
I can't see what are the benefits of your change. Could you explain why using application:get_env/2 is not good?

[dcy]

When i use apns:connect/1(config like above), i must add {apns, [{timeout, 10000}]} to sys.config.
Or application:get_env(apns, timeout, 10000) is better.
It is not problem about application:get_env(apns, timeout), It is about when i do not want to use any application apns's config(application:get_env(apns, xxx)), I should add at least one timeout config {apns, [{timeout, 10000}]} to sys.config.

[elbrujohalcon]

@ferigis also, @dcy's alternative makes the timeout configurable per-connection, instead of being an application-wide parameter.
In this PR I would object the use of maps:get in contrast of the more debugger friendly pattern-matching construct. In other words, I would use…

#{timeout := Timeout} = Connection

…instead of…

Timeout = maps:get(timeout, Connection)

…but that's just bike-shedding.

[ferigis]

@dcy merged! thanks for the contribution! :)