Add additional meta variable

Add additional meta variables in the logging context on top of the ones that are readily collected in get_logger_meta_variables function. It might be needed to add some other metadata specific to the logging usage - that goal is served by this function.

Usage

.add_meta_variables(
  additional_fields = NULL,
  log_level = NULL,
  namespace = NA_character_,
  .logcall = sys.call(),
  .topcall = sys.call(-1),
  .topenv = parent.frame()
)

Arguments

additional_fields

A named vector of type list with key-value pairs of additional meta data which needs to be added in logging context on top of log_fields. The respective value of each key is expected to be of length 1. It is NULL by default.

log_level

log level as per log_levels

namespace

string referring to the logger environment / config to be used to override the target of the message record to be used instead of the default namespace, which is defined by the R package name from which the logger was called, and falls back to a common, global namespace.

.logcall

the logging call being evaluated (useful in formatters and layouts when you want to have access to the raw, unevaluated R expression)

.topcall

R expression from which the logging function was called (useful in formatters and layouts to extract the calling function's name or arguments)

.topenv

original frame of the .topcall calling function where the formatter function will be evaluated and that is used to look up the namespace as well via logger:::top_env_name

Value

Returns a vector of collected meta-data. It is used in defining the log_layout function.