[erlang-questions] Use of application environment

Martin Logan <>
Tue Dec 2 21:54:48 CET 2008


I have been doing the same for years, I find it works better.  Though I try
to keep calls to config fairly isolated choosing to pass config through as
function args whenever possible.   I wrapped config with another application
called GAS ( http://erlware.org/lib/5.6.3/gas-6.1.1/) that I find works
nicely in that I can set config at run time and have it reflected ultimately
in my config file if I so choose.  I have also added the ability to use
config file overriding, though only one level deep.

Chers,
Martin


On 11/24/08 9:27 PM, "Edwin Fine" <> wrote:

> Hi all,
> 
> Is it considered bad practice to use application environment variables (i.e.
> application:get_env/2,3) in workers, as opposed to only passing config
> information via the start()/init() calls? I am finding it tedious as I add
> more configuration data to the sys.config file, to get_env() the data in a
> supervisor and then parcel it out to the workers. Also, it becomes a pain to
> change the values at runtime, whereas if I put a function like this in an
> affected worker
> 
> my_foo_val() ->
>     application:get_env(my_app, my_foo_val, ?SOME_SANE_DEFAULT).
> 
> then runtime changes can be made immediately using set_env(), and it becomes
> much easier to add new config data, but I feel uneasy, almost as if I'm using
> global variables. From a load point of view, I only do this in places where
> the value is not used at a high rate.
> 
> What is the preferred or recommended (or even most common) practice?
> 
> Regards,
> Edwin Fine
> 
> 
> _______________________________________________
> erlang-questions mailing list
> 
> http://www.erlang.org/mailman/listinfo/erlang-questions


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