logger

module:logger

Description:

  • Logging utility Default level is log but it can be set via env variables even without app initialzation

    • BKJS_LOG_LEVEL - set to any string/number level
    • BKJS_LOG_FILTER - enable debug filters
Properties:
Name Type Description
level int

current logging level
levels object

levels sorted by priorities: ERROR, WARN, LOG, INFO, DEBUG, DEV
filters object

debugging filters enabled
Example
logger.setLevel("info")
logger.log("log")             // visible
logger.info("info")           // visible
logger.debug("debug")         // not visible
logger.error("error")         // visible

logger.setLevel("debug")
logger.debug("debug")         // visible

logger.setLevel("info")
logger.setDebugFilter("custom")
logger.debug("debug")         // still not visible
logger.debug("custom")        // visible

Methods

(static) debug(…args)

Description:

  • Log with DEBUG level, enabled debug filter will be logged if matched

Parameters:
Name Type Attributes Description
args any <repeatable>

(static) dev(…args)

Description:

  • Log with DEV level

Parameters:
Name Type Attributes Description
args any <repeatable>

(static) error(…args)

Description:

  • Log with ERROR level

Parameters:
Name Type Attributes Description
args any <repeatable>

(static) info(…args)

Description:

  • Log with INFO level

Parameters:
Name Type Attributes Description
args any <repeatable>

(static) log(…args)

Description:

  • Log with LOG level

Parameters:
Name Type Attributes Description
args any <repeatable>

(static) logger(level, …args)

Description:

  • A generic logger method, safe, first arg is supposed to be a logging level, if not valid the error level is used

Parameters:
Name Type Attributes Description
level string

logging level, can be one of the default levels or custom one registered with {registerLevel}
args any <repeatable>

arguments to log

(static) none(…args)

Description:

  • Log with NONE level, no-op

Parameters:
Name Type Attributes Description
args any <repeatable>

(static) prefix(level)

Description:

  • Build message prefix, depends on the options: date(1), pid(process.pid), tag(""), can be set via setOptions, by default

    • date is $BKJS_LOG_DATE or datetime or iso or utc or none
    • pid is $BKJS_LOG_PID or current process pid
    • tag is $BKJS_LOG_TAG
    • role is $BKJS_LOG_ROLE
Parameters:
Name Type Description
level string

(static) registerLevel(level, callback, optionsopt)

Description:

  • Register a custom level handler, must be invoked via logger.logger only, if no handler registered for given level the whole message will be logger as an error. The custom hadnler is called in the context of the module which means the options are available inside the handler.

Parameters:
Name Type Attributes Description
level string

custom log level
callback function

call it for this level
options Object <optional>
Properties
Name Type Attributes Description
format boolean <optional>

if true then all arguments will be formatted into one line as for the regular levels and passed the handler as one argument, this is to support different transport and preserve the same standard logging format

(static) setDebugFilter(label, {function)

Description:

  • Enable debugging level for this label, if used with the same debugging level it will be printed regardless of the global level, a label is first argument to the logger.debug methods, it is used as is, usually the fist argument is the current function name with comma, like logger.debug("select:", name, args)

Parameters:
Name Type Description
label string

label(s) to debug, can be a comma separated list
{function

handler - can be a function to be used instead of regular logging, this is for rerouting some output to a custom console or for dumping the actual Javascript data without preformatting, most useful to use console.log

(static) setFile(file)

Description:

  • Redirect logging into a file

Parameters:
Name Type Description
file string

(static) setLevel(level)

Description:

  • Set the output level, it can be a number or one of the supported level names, on invalid level then WARN is set

Parameters:
Name Type Description
level stream

(static) setOptions(options)

Description:

  • Special options for logger to override defaults, syslog options must start with syslog- For tag, date, pid values may refer to other env variables if start with $, like BKJS_LOG_TAG='$BKJS_TAG'

Parameters:
Name Type Description
options Object
Properties
Name Type Attributes Description
filter string <optional>

debug filters
level string <optional>

set current level
tag string <optional>

syslog tag
pid int <optional>

process id
date date <optional>

date format: datetime, iso, utc
syslog-hostname string <optional>

syslog hostname to use
syslog-facility string <optional>

syslog hostname to use
syslog-bsd boolean <optional>

syslog version
syslog-rfc5424 boolean <optional>

syslog version
syslog-rfc3164 boolean <optional>

syslog version

(static) setSyslog(facility)

Description:

  • Enable or close syslog mode

Parameters:
Name Type Description
facility int | string

syslog facility as a number or remote syslog server:
Example
unix://
udp://host?tag=app
tcp://host:514?facility=LOG_LOCAL0

(static) trace()

Description:

  • Print stack backtrace as error

(static) warn(…args)

Description:

  • Log with WARN level

Parameters:
Name Type Attributes Description
args any <repeatable>