Kony Fabric console User Guide: SDKs > Kony Visualizer SDK > Using Log SDK

Kony Logger

Introduction

Kony Logger is introduced to persist logs based on six log levels:

Trace
Debug
Info
Warn
Error
Fatal

The logger feature provides three ways of providing logs to output: console, file and network. The logger feature is defined in the namespace kony.logger. Each log will be printed as per the below syntax:

 [LoggerInstanceName][AppID AppVersion][TimestampTimeZone][LogLevel][SessionID][ThreadInformation][DeviceId][DeviceOSInfo][FileName][ClassName][MethodName][LineNo]Message

Scope

The Kony Logger feature is available for Kony Visualizer, Android, iOS, and Windows 10.

Properties

kony.logger exposes the below properties:

currentLogLevel

currentLogLevel sets the log level of the logger to any of the six mentioned levels. setting to a certain level will allow the logs of that level and above to be persisted. For instance, if the currentLogLevel is set to Error, only the error and fatal log statements are printed.

Syntax	JavaScript: kony.logger.currentLogLevel
Possible Values	The below log levels may be set to the current log level: kony.logger.logLevel.ALL kony.logger.logLevel.NONE kony.logger.logLevel.TRACE kony.logger.logLevel.DEBUG kony.logger.logLevel.INFO kony.logger.logLevel.WARN kony.logger.logLevel.ERROR kony.logger.logLevel.FATAL
Default Value	kony.logger.logLevel.NONE
Read or Write	Yes (Read and Write)
JavaScript Example	kony.logger.currentLogLevel = kony.logger.logLevel.DEBUG;

APIs

Multiple instances of the logger can be created using APIs. The console and the file can be activated as a part of the configuration, if required. The below APIs are introduced to create logger, activate persistors and generate the logs.

createFilePersistor()

The createFilePersistor() API is used to create the configuration for the file persistor. This configuration can be used with the loggerConfig object (For more information, refer addPersistor API).

Note: In Visualizer Android, if you want activate file persistor and view the logs in the file, you need to add WRITE_EXTERNAL_STORAGE under Permissions tab.

Signature	JavaScript: createFilePersistor
Parameters	N/A
Return Type	The API return a fileConfig object. The below properties have been exposed on the file persistor. maxFileSize maxNumberOfLogFiles
JavaScript Example	var persistor1 = new kony.logger.createFilePersistor(); persistor1.maxFileSize = 100; persistor1.maxNumberOfLogFiles = 15;
Platform Availability	Available on IDE, Android, iOS, and Windows 10

maxFileSize

The maxFileSize API is used to define the maximum size of the files created in bytes.

Syntax	maxFileSize
Type	Number
Possible Values	Positive Integer
Default Value	10000
Read or Write	Only Write
JavaScript Example	var persistor1 = new kony.logger.createFilePersistor(); persistor1.maxFileSize = 10000;

maxNumberOfLogFiles

To define the maxNumberOfLogFiles the app can have at a maximum during any instant. The filePersistor is a rolling file appender i.e. the data of latest configured files is preserved.

Syntax	maxNumberOfLogFiles
Type	Number
Possible Values	Non-zero, Positive Integer
Default Value	10
Read or Write	Only Write
JavaScript Example	var persistor1 = new kony.logger.createFilePersistor(); persistor1.maxNumberOfLogFiles = 20;

createLoggerConfig()

CreateLoggerConfig() is used to create the configuration object for the logger. This object is used in the createNewLogger() API. The object has various properties exposed to define our configuration. To apply the configuration, you need to use setConfig() API . When you pass the object through createNewLogger() API , configuration object is immediately applied .

Signature	Javascript: createLoggerConfig
Parameters	N/A
Return Type	The API returns a loggerConfig Object. All the properties are static and affect all the logger instances. The below properties have been exposed. bytesLimit statementsLimit timeFormat timeZone overrideConfig logLevel addPersistor
JavaScript Example	Example 1: var loggerConfig = new kony.logger.createLoggerConfig(); Example 2: var loggerConfig = new kony.logger.createLoggerConfig(); loggerConfig.bytesLimit = 10000; loggerConfig.statementsLimit = 10; loggerConfig.timeFormat = "dd-MM-yyyy HH.mm.ss.SSS"; loggerConfig.timeZone = "UTC"; loggerConfig.overrideConfig = true; loggerConfig.logLevel= kony.logger.logLevel.INFO.value;
Platform Availability	IDE, Android, iOS, and Windows 10

bytesLimit

The console logs will be printed as soon as the logging methods are invoked. It is performance intensive to persist the logs one by one on the file. The bytesLimit can be used to accumulate the logs until the bytesLimit is reached and then flushed onto the file.

Syntax	bytesLimit
Type	Number
Possible Values	Any positive integer
Default Value	10000
Read or Write	Only Write
JavaScript Example	var loggerConfig = new kony.logger.createLoggerConfig(); loggerConfig.bytesLimit = 20000;

statementsLimit

The console logs will be printed as soon as the logging methods are invoked. It is performance intensive to persist the logs one by one on the file. The statementsLimit can be used to accumulate the logs until the specified number of statements are reached and then flushed onto the file.

Syntax	statementsLimit
Type	Number
Possible Values	Any non-negative integer
Default Value	20
Read or Write	Only Write
JavaScript Example	var loggerConfig = new kony.logger.createLoggerConfig(); loggerConfig.statementsLimit = 30;

timeFormat

Each log is printed in a specified format. The format includes the timestamp. This property is used to specify the syntax of the timeFormat.

Syntax	timeFormat
Type	String
Possible Values	Any valid time format pattern
Default Value	"dd-mm-yyyy HH.mm.ss.SSS"
Read or Write	Only Write
JavaScript Example	var loggerConfig = new kony.logger.createLoggerConfig(); loggerConfig.timeFormat = "dd-MM-yyyy HH.mm.ss.SSS";

timeZone

Each log is printed in a specified format. The format includes the timestamp. This property is used to specify the syntax of the timeZone.

Syntax	timeZone
Type	String
Possible Values	UTC, LocalTime
Default Value	UTC
Read or Write	Only Write
JavaScript Example	var loggerConfig = new kony.logger.createLoggerConfig(); loggerConfig.timeZone = "UTC";

overrideConfig

All the properties are exposed by loggerConfig. Changing the property and using setConfig() API will affect all the logger instances created. overrideConfig is used to specify if the configuration should override the existing configuration.

Syntax	overrideConfig
Type	Bool
Possible Values	True or False
Default Value	True
Read or Write	Only Write
JavaScript Example	var loggerConfig = new kony.logger.createLoggerConfig(); loggerConfig.overrideConfig = false;

logLevel

The logLevel property works similar to currentLogLevel property. There are six log levels in the logLevel property.

Syntax	logLevel
Possible Values	kony.logger.logLevel.ALL kony.logger.logLevel.NONE kony.logger.logLevel.TRACE kony.logger.logLevel.DEBUG kony.logger.logLevel.INFO kony.logger.logLevel.WARN kony.logger.logLevel.ERROR kony.logger.logLevel.FATAL
Default Value	kony.logger.logLevel.NONE
Read or Write	Only Write
JavaScript Example	var loggerConfig = new kony.logger.createLoggerConfig(); loggerConfig.logLevel = kony.logger.logLevel.INFO.value;

addPersistor

The property can be used to add file persistor through loggerConfig object.

Syntax	addPersistor
Possible Values	Object of type filePersistor
Default Values	N/A
Read or Write	Only Write
JavaScript Example	var loggerConfig = new kony.logger.createLoggerConfig(); var filePers = new kony.logger.createFilePersistor(); filePers.maxNumberOfLogFiles = 15; loggerConfig.addPersistor(filePers);

createNewLogger() API

Signature	createNewLogger
Parameters	This API takes three parameters: LoggerName, LoggerConfig loggerName: The loggerName is a string used to identify the instance of the loggerObject. *Note:* This is a mandatory value. loggerConfiguration: The loggerConfiguration is the configuration object. For more information, refer createLoggerConfig().
Return Type	Returns a logger object on which various functions such as trace(), debug(), info(), warn(), error() and fatal() APIs are exposed.
JavaScript Example	var lConfig = new kony.logger.createLoggerConfig(); var loggerObj = new kony.logger.createNewLogger("AndroidLoggerDemo", lConfig);
Platform Availability	IDE, Android, iOS, and Windows 10

activatePersistors()

Unless we activate persistors, logs will not be pushed to the corresponding persistors. This is a mandatory step and no persistor is activated by default.

Signature	activatePersistors
Parameters	The API takes one parameter: persistor name. This parameter could be either a console or a file.
Return Type	N/A
JavaScript Example	kony.logger.activatePersistors(kony.logger.consolePersistor) kony.logger.activatePersistors(kony.logger.filePersistor) kony.logger.activatePersistors(kony.logger.consolePersistor \| kony.logger.filePersistor)
Platform Availability	IDE, Android, iOS, and windows 10

Note: Console Persistor logs will not be available in Visualizer Windows 10 and Native Windows 10.

deactivatePersistors()

If you want to make sure the logs are not pushed to a corresponding persistor or any combination of them, use deactivatePersistors() API.

Signature	deactivatePersistors
Parameters	The API takes one parameter: persistor name. This parameter could be either a console or a file or any combination of these.
Return Type	N/A
JavaScript Example	kony.logger.deactivatePersistors(kony.logger.consolePersistor) kony.logger.deactivatePersistors(kony.logger.filePersistor) kony.logger.deactivatePersistors(kony.logger.consolePersistor \| kony.logger.filePersistor)
Platform Availability	IDE, Android, iOS, and windows 10

trace() API

The trace() API is used to trace log level messages.

Signature	trace
Parameters	The API takes one parameter – a string input log that must be persisted.
Return Type	N/A
JavaScript Example	Var lconfig = new kony.logger.createNewLoggerConfig(); loggerobj = new kony.logger.createNewLogger("AndroidLoggerDemo", lconfig); loggerobj.trace("Message to be added in Trace");
Platform Availability	IDE, Android, iOS, and windows 10

debug() API

The debug() API is used to log the debug level messages:

Signature	debug
Parameters	The API takes one parameter – a string input log that must be persisted
Return Type	N/A
JavaScript Example	Var lconfig = new kony.logger.createNewLoggerConfig(); loggerobj = new kony.logger.createNewLogger("AndroidLoggerDemo", lconfig); loggerobj.debug("Message to be added in Debug");
Platform Availability	IDE ,Android , iOS and windows 10

info() API

The info() API is used to log the info level messages.

Signature	info
Parameters	The API takes one parameter – a string input log that must be persisted.
Return Type	N/A
JavaScript Example	Var lconfig = new kony.logger.createNewLoggerConfig(); loggerobj = new kony.logger.createNewLogger("AndroidLoggerDemo", lconfig); loggerobj.info("Message to be added in Info");
Platform Availability	IDE, Android, iOS, and windows 10

error() API

The error() API is used to log the error messages:

Signature	error
Parameters	The API takes one parameter – a string input log that must be persisted.
Return Type	N/A
JavaScript Example	Var lconfig = new kony.logger.createNewLoggerConfig(); loggerobj = new kony.logger.createNewLogger("AndroidLoggerDemo", lconfig); loggerobj.error("Message to be added in Error");
Platform Availability	IDE, Android, iOS, and windows 10

warn() API

The warn() API is used to log the warning messages:

Signature	warn
Parameters	The API takes one parameter – a string input log that must be persisted
Return Type	N/A
JavaScript Example	Var lconfig = new kony.logger.createNewLoggerConfig(); loggerobj = new kony.logger.createNewLogger("AndroidLoggerDemo", lconfig); loggerobj.warn("Message to be added in Warn");
Platform Availability	IDE, Android, iOS, and windows 10

fatal() API

The fatal() API is used to log the fatal messages:

Signature	fatal
Parameters	The API takes one parameter – a string input log that must be persisted
Return Type	N/A
JavaScript Example	Var lconfig = new kony.logger.createNewLoggerConfig(); loggerobj = new kony.logger.createNewLogger("AndroidLoggerDemo", lconfig); loggerobj.fatal("Message to be added in fatal");
Platform Availability	IDE, Android, iOS, and windows 10

flush() API

The flush() API is used to flush all the statements onto the activated persistors regardless whether the bytesLimit or statementsLimit are met.

Signature	flush
Parameters	N/A
Return Type	N/A
JavaScript example	kony.logger.flush();
Platform Availability	IDE, Android, iOS, and windows 10

setconfig() API

The setconfig() API is a convenience API used to set LoggerConfig (mentioned earlier). Since loggerConfig is a singleton, If you set the loggerConfig once, it is applied across all the logger objects.

Signature	setConfig
Parameters	loggerConfig
Return Type	N/A
JavaScript Example	Var logConfig = new kony.logger.createLoggerConfig(); kony.logger.setConfig(logConfig);
Platform Availability	IDE, Android, iOS, and windows 10

setPersistConfig()

The setPersistConfig() API is used to change persistorConfig or set it to fresh, when it is not set through loggerConfig. As the persistors are singletons, they will have impact on all loggerObjects when set.

Signature	setPersistorConfig
Parameters	persistor
Return Type	N/A
JavaScript Example	Var filePers = new kony.logger.createFilePersistor(); filePers.maxNumberOfFiles = 1; kony.logger.setPersistorConfig(filePers);
Platform Availability	IDE, Android, iOS, and Windows 10

App Logger

The default logger Instance created can be used to write log statements. If the user wants to create additional logger instances he is free to do so. The logger name used for appLogger is konyLogger.

Usage

 kony.logger.appLogger.error("Message to be logged at error log level");
kony.logger.appLogger.debug("Message to be logged at error log level");
kony.logger.appLogger.trace("Message to be logged at error log level");

Usage Guidelines/Restrictions/Examples

 //Create Logger Configuration
var lConfig = new kony.logger.createLoggerConfig();
//Create FilePersistor
Var persistor1 = new kony.logger.createFilePersistor();
//Add Persistor to the loggerConfig
lConfig.addPersistor(persistor1);
//Create Logger Object
loggerObj = new kony.logger.createNewLogger("UserLogs", lConfig);
kony.logger.activatePersistors(kony.logger.consolePersistor);
kony.logger.activatePersistors(kony.logger.filePersistor);
kony.logger.currentLogLevel = kony.logger.logLevel.INFO;
//Print Statements
for(var i=0;i<20;i++){
var msg = "statement" + i;
loggerObj.debug("Message in debug level" + msg);
loggerObj.trace("Message in trace level" + msg);
loggerObj.fatal("Message in Fatal level" + msg);
loggerObj.info("Message in Info level" + msg);
loggerObj.warn("Message in warn level" + msg);
loggerObj.error("Message in error level" + msg);
}

Note:

Unlike the file and console persistors, the network persistor is always enabled and can be managed from Kony Fabric Admin Console. Do not create/activate/deactivate the network persistor from the client application code. For more details on configuring Network Persistor, refer to the Log Level by Client Filters section in the Standard Logs doc.
To manage middleware logs, refer to App Services > Logs.
Running the logger on Android devices that run on Android Lollipop or earlier versions with less than 1GB RAM may cause memory issues. These memory issues are at the Android OS level and have been declared obsolete by Google. For more information, refer to the Issue Tracker.