loglevel-mixin

loglevel-mixin

Injects methods named after a set of logLevels which are only forwarding messages if the current logLevel is higher or equal to the logLevel the name of the called method reflects.

usage

const llm = require('loglevel-mixin');

let someObject = { log(level,message) { console.log(`${level} ${message}`); } };

llm.defineLoggerMethods(someObject);
llm.defineLogLevelProperties(someObject);

someObject.logLevel = 'error';
someObject.info( level => 'my info message (not reported since logLevel is error)')
someObject.logLevel = 'info';
someObject.info( level => 'my info message (reported since logLevel is now info)')

works for ES2015 classes to

const llm = require('loglevel-mixin');

class BaseClass {
  log(level, message) { console.log(`${level} ${message}`); }
}

llm.defineLoggerMethods(BaseClass.prototype);

class LoggingEnabledClass extends llm.LogLevelMixin(BaseClass) {
}

const someObject = new LoggingEnabledClass();

someObject.logLevel = 'error';
someObject.info( level => 'my info message (not reported since logLevel is error)')
someObject.logLevel = 'info';
someObject.info( level => 'my info message (reported since logLevel is now info)')

install

With npm do:

npm install loglevel-mixin

API Reference

• loglevel-mixin

loglevel-mixin~declareLevels(list) ⇒ object

Generate the loglevel objects out of a list of log level names.

Kind: inner method of loglevel-mixin
Returns: object - levels object A hash with all the loglevels. Stored by there name.

Param	Type	Description
list	Array.<string>	A list of log level names. The last name in the list will become the one with the highest priority.

loglevel-mixin~defineLoggerMethods(object, logLevels, theFunction) ⇒ void

Adds logging methods to an existing object. For each loglevel a method with the name of the log level will be created.

Kind: inner method of loglevel-mixin

Param	Type	Description
object	object	target where to assign properties to
logLevels	object	Hash with all the available loglevels. Stored by there name
theFunction	function	The function to be added under the loglevel name. This function will only be called if the current loglevel is greater equal the log level of the called logging function. By default a method log(level,message) will be used

loglevel-mixin~defineLogLevelProperties(object, logLevels, defaultLogLevel)

Declares two properties: logLevel {String} info,error,... logLevelPriority {Number}

Kind: inner method of loglevel-mixin

Param	Type	Description
object	object	target where the properties will be written into
logLevels	object	Hash with all the available loglevels. Stored by there name; defaults to defaultLogLevels
defaultLogLevel	string	the default value for the properties; defaults to info

loglevel-mixin~makeLogEvent(level, arg, args) ⇒ object

Helper function to aggregate values into a log event

Kind: inner method of loglevel-mixin
Returns: object - suitable for log event processing

Param	Type	Description
level	string	log level
arg	string | object	original log message - level and timestamp may be overwritten
args	object	additional values to be merged into the final log event - values have precedence

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license

BSD-2-Clause