Logging macro incompatibility (OTP >= v21) #136
Description
An issue arises if the new(-ish) logging macros (kernel/include/logger.hrl) are included alongside wf.hrl, specifically, ?LOG is redefined. I cannot see a 100% backwards compatible solution to this problem as logger:?LOG accepts different arguments than wf:?LOG. (It's entirely possible my understanding of how includes works is faulty or incomplete.)
If this is something that should be addressed in Nitrogen, I'd propose a solution like
%%% LOGGING %%%
-ifndef(debug_print).
-define(debug_print, true).
-ifndef(LOGGER_HRL).
-define(PRINT(Var), error_logger:info_msg("DEBUG: ~p~n~p:~p~n~p~n ~p~n", [self(), ?MODULE, ?LINE, ??Var, Var])).
-define(LOG(Msg, Args), error_logger:info_msg(Msg, Args)).
-define(DEBUG, error_logger:info_msg("DEBUG: ~p:~p~n", [?MODULE, ?LINE])).
-else.
%% logger.hrl has been included
%% ?LOG has already been defined
-define(WFLOG(Msg, Args), ?LOG_INFO(Msg, Args)).
-define(PRINT(Var), ?LOG_INFO("DEBUG: ~p: ~p~n", [??Var, Var])).
-define(DEBUG, ?LOG_INFO("DEBUG: ~p:~p~n", [?MODULE, ?LINE])).
-endif.
-endif.which allows for both hrl files to be included, in this order:
-include_lib("kernel/include/logger.hrl").
-include_lib("nitrogen_core/include/wf.hrl").This is an incomplete (and not well tested) solution! wf:info/1,2; wf:warning/1,2; and wf:error/1,2 will continue to use the legacy logging infrastructure. Further, the alternate macros do not take advantage of the enhanced metadata the new logging facility provides (which would require, I think, a custom log formatter).
I'm happy to submit a PR addressing this issue, either along these lines or a better solution arising from discussion. Before continuing however, I think it's important to acknowledge the compatibility issue that will arise and determine how it should be managed. It seems to be worth noting that the incompatibility is triggered by the developer opting to include the new macros; the default logging should just work in the vanilla case.