@novivia/logger
v0.6.3
Published
Novivia event logger.
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Logger utility
Installation
yapm install
During the transition period from npm to yapm you can still do:
json5 -c package.json5
to generate the package.json
file required by npm.
NEVER EDIT package.json
DIRECTLY.
Usage
Log a message
var logger = require("logger")(module);
// Examples.
logger.log("info", "message");
logger.log("info", "message", {anything: "Meta data!"});
logger.info("possible to directly call the level on logger");
logger.warn("Supports %s.", "util.format()'s printf-like interpolation");
The log message will be prepended with the current date and time in the following format: YYYY-MM-DD HH:MM:SS. The timezone will be the local one when in development, UTC otherwise.
The log message will also display between brackets the name of the package inferred from the provided module object, to easily distinguish the emitter.
Note: Any uncaught exception will be caught by the logger, at which point it will display a detailed trace before exiting the application.
Logging levels
The following logging levels, in order of least to most critical, are allowed:
silly
Something really really specific, about something already specific. Or something not really noteworthy, in any case. Most of the time it's better to not log it at all, otherwise it would just be silly.
debug
Something pretty specific, but useful to have if having elementary problems. Most of the time this will log one iteration of a loop over a collection, for example.
verbose
Something rather general about a portion of code, but that allows to understand what is the flow of an application when put together with other verbose calls.
info
Something important to know about the application, but that is expected, informative and not negative.
warn
Something for which a flag needs to be raised but that is not necessarily critical.
error
Something critical that requires immediate attention.
By default the lowest level for which the logs are displayed is info, but that is lowered to verbose in a development environment. If required, the minimum level can be changed by doing the following:
var logger = require("logger")(module);
// Examples.
logger.debug("message"); // Will not display.
logger.setConsoleLevel("silly");
logger.debug("message"); // Will display.
logger.setConsoleLevel(); // Will revert to the default level for the
// original environment.
Keep in mind that multiple modules can be using this module simultaneously and
a call to setConsoleLevel
only affects the logger on which it is applied, use
this to your advantage.