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    easyloggingpp

    9.96.7 • Public • Published

    Easylogging++ Node.js Binding

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    Easylogging++ Node.js binding provides ability to use efficient Easylogging++ to log important logs for your application.

    Requirements

    • Node 7+

    Download

    npm install --save easyloggingpp
    

    Getting Started

    const easyloggingpp = require('easyloggingpp');
    const ConfigType = easyloggingpp.ConfigType;
    const Level = easyloggingpp.Level;
    const logger = easyloggingpp.getLogger('mylogger'); // register logger
     
    easyloggingpp.configureAllLoggers([
        {
            config: ConfigType.Format,
            value: '%levshort %datetime %fbase:%line %msg',  // <-- fbase or file for full path
        },
        {
            config: ConfigType.Filename,
            value: 'logs/output.log'
        }
    ]);
     
    // alternatively you can use following to set default configurations
    // for future loggers as well as existing logger
    easyloggingpp.configureAllLoggers({
        config_file: 'easylogging-config.conf',
    });
     
    logger.info('simple log');
    logger.info('array %s', [1, 2, 3]);
    var person = { 'name': 'Adam', 'age': 960, }
    logger.info('obj %s', person);
     
    logger.error('an error occurred %s', new Error("error msg"));
     
    easyloggingpp.setLogErrorStack(false); // turn stack logging off
    logger.fatal('serious error occurred %s', new Error("fatal msg"));
    logger.error('an error occurred %s', new Error("error msg"));

    Above will print something like: sample-output

    Log

    logger.info(...);
    logger.warn(...);
    logger.error(...);
    logger.debug(...);
    logger.trace(...);
    logger.fatal(...);
    logger.verbose(verbose_level, ...);

    Log Formats

    You can use advanced logging format specifiers.

    logger.info('array %s', [1, 2, 3]);
    

    Taken from utils.format

    Format specifier Explanation
    %s String.
    %d Number (integer or floating point value).
    %i Integer.
    %f Floating point value.
    %j JSON. Replaced with the string '[Circular]' if the argument contains circular references.
    %% single percent sign ('%'). This does not consume an argument.

    %o and %O should not be used. Use %s instead for better output.

    Global Configuration

    via File

    easyloggingpp.configureAllLoggers({
        config_file: 'easylogging-config.conf',
    });

    This will configure all the existing loggers and set this new configuation to default for future loggers.

    All Levels

    easyloggingpp.configureAllLoggers({
        config: easyloggingpp.ConfigType.Format,
        value: '%datetime %msg',
    });

    or using array

    easyloggingpp.configureAllLoggers([
      {
          config: easyloggingpp.ConfigType.Format,
          value: '%datetime %msg',
      },
      {
        config: easyloggingpp.ConfigType.Format,
        value: '%datetime %file:%line %msg',
      }
    ]);

    This will configure existing loggers but will not change future loggers.

    Specific Level

    easyloggingpp.configureAllLoggers({
        level: easyloggingpp.Level.Info,
        config: easyloggingpp.ConfigType.Format,
        value: '%datetime %msg',
    });

    or using array

    easyloggingpp.configureAllLoggers([
      {
          level: easyloggingpp.Level.Info,
          config: easyloggingpp.ConfigType.Format,
          value: '%datetime %msg',
      },
      {
        level: easyloggingpp.Level.Debug,
        config: easyloggingpp.ConfigType.Format,
        value: '%datetime %file:%line %msg',
      }
    ]);

    This will configure existing loggers but will not change future loggers.

    Logger Configuration

    via File

    const logger = easyloggingpp.getLogger('logger1');
    logger.configure({
        config_file: 'easylogging-config.conf',
    });

    All Levels

    const logger = easyloggingpp.getLogger('logger1');
     
    logger.configure({
        config: easyloggingpp.ConfigType.Format,
        value: '%datetime %msg',
    });

    or using array

    const logger = easyloggingpp.getLogger('logger1');
    logger.configure({
        config: easyloggingpp.ConfigType.Format,
        value: '%datetime %msg',
    });

    Specific Level

    const logger = easyloggingpp.getLogger('logger1');
     
    logger.configure({
        config: easyloggingpp.ConfigType.Format,
        value: '%datetime %msg',
    });

    or using array

    const logger = easyloggingpp.getLogger('logger1');
    logger.configure({
        config: easyloggingpp.ConfigType.Format,
        value: '%datetime %msg',
    });

    This will configure existing loggers but will not change future loggers.

    Add/Remove Logging Flag

    easyloggingpp.addFlag(easyloggingpp.LoggingFlag.ColoredTerminalOutput);
    easyloggingpp.removeFlag(easyloggingpp.LoggingFlag.ColoredTerminalOutput);

    Profiler

    You can use built-in profiler

    logger.startProfiling('profiling-id');
    // some heavy task
    for (var i = 0; i < 100000; ++i) {
     
    }
    logger.endProfiling('profiling-id');
     
    // other tasks that will not be profiled
    // if needed or you could use finishProfiling directly
     
    logger.finishProfiling('profiling-id', (item) => {
        logger.info(`finished profiling in ${item.diff}ms`);
    });

    Notes

    Some notes for those who have previous experience with Easylogging++ (and for those who are absolutely new)

    • Logs are written to /dev/null by default. You must configure via easyloggingpp.configureAllLoggers at initialization.
    • Loggers are created automatically when you use easyloggingpp.getLogger.
    • ColoredTerminalOutput flag is set by default. You can unset it using easyloggingpp.removeFlag
    • You can safely log with Fatal level as DisableApplicationAbortOnFatalLog flag is set by default. You should not remove this flag. Read more

    License

    Copyright 2017-present Zuhd Web Services
    Copyright 2017-present @abumusamq
    
    https://github.com/zuhd-org
    https://zuhd.org
    https://muflihun.com
    
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at
    
        http://www.apache.org/licenses/LICENSE-2.0
    
    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
    

    Install

    npm i easyloggingpp

    DownloadsWeekly Downloads

    2

    Version

    9.96.7

    License

    Apache-2.0

    Unpacked Size

    7.11 MB

    Total Files

    26

    Last publish

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