Logger

ThinkJS implements powerful logging capabilities via the think-logger3 module and provides adapter extensions that easily extend the built-in logging module. By default, the log4js module is used as the underlying logging module. It has many features such as log classification, log splitting and multi-process.

How To Use

System has been globally injected the logger object think.logger, it provides debug, info, warn and error four methods to output log, the default behaviour is to output to console.

think.logger.debug('debug message');
think.logger.info('info message');
think.logger.warn('warning');
think.logger.error(new Error('error'));

Confguration

The system coms with Console, File, DateFile three adapter. The default is to use Controle to output logs to console.

File

If you want to output log to file, add the following configurations into src/config/adapter.js file:

const path = require('path');
const {File} = require('think-logger3');

exports.logger = {
  type: 'file',
  file: {
    handle: File,
    backups: 10,
    absolute: true,
    maxLogSize: 50 * 1024,  //50M
    filename: path.join(think.ROOT_PATH, 'logs/xx.log')
  }
}

Then initial log would create a file called debug.log. After this file reached maxLogSize, a new file named debug.log.1 will be created. After log file number reached backups, old log chunk file will be removed.

• filename: log filename
• maxLogSize: The maximum size (in bytes) for a log file, if not provided then logs won't be rotated.
• backups: The number of log files to keep after logSize has been reached (default 5)
• absolute: If filename is a absolute path, the absolute value should be true.
• layout: Layout defines the way how a log record is rendered. More layouts can see here.

DateFile

This adapter will log to a file, moving old log messages to timestamped files according to a specified pattern. For example:

const path = require('path');
const {DateFile} = require('think-logger3');

exports.logger = {
  type: 'dateFile',
  dateFile: {
    handle: DateFile,
    level: 'ALL',
    absolute: true,
    pattern: '-yyyy-MM-dd',
    alwaysIncludePattern: false,
    filename: path.join(think.ROOT_PATH, 'logs/xx.log')
  }
}

Then initial log would create a file called debug.log. At midnight, the current debug.log file would be rename to debug.log-2017-03-12(for example), and a new debug.log file created.

• level: log level
• filename: log base filename
• pattern: date filename would append to filename. A new file is started whenever the pattern for the current log entry differs from that of the previous log entry. The following strings are recognised in the pattern:
  • yyyy - the full year, use yy for just the last two digits
  • MM - the month
  • dd - the day of the month
  • hh - the hour of the day (24-hour clock)
  • mm - the minute of the hour
  • ss - seconds
  • SSS - milliseconds (although I'm not sure you'd want to roll your logs every millisecond)
  • O - timezone (capital letter o)
• alwaysIncludePattern: If alwaysIncludePattern is true, then the initial file will be filename.2017-03-12 and no renaming will occur at midnight, but a new file will be written to with the name filename.2017-03-13.
• absolute: If filename is a absolute path, the absolute value should be true.
• layout: Layout defines the way how a log record is rendered. More layouts can see here.

Advance

If those adapter configuration can't satisfy your need, you can use this adapter and set config like log4js. For example:

const path = require('path');
const {Basic} = require('think-logger3');

exports.logger = {
  type: 'advanced',
  advanced: {
    handle: Basic,
    appenders: {
      everything: { 
        type: 'file', 
        filename: path.join(think.ROOT_PATH, 'logs/all-the-logs.log') 
      },
      emergencies: {  
        type: 'file', 
        filename: path.join(think.ROOT_PATH, 'logs/oh-no-not-again.log') 
      },
      'just-errors': { 
        type: 'logLevelFilter', 
        appender: 'emergencies', 
        level: 'error' 
      }
    },
    categories: {
      default: { 
        appenders: ['just-errors', 'everything'], 
        level: 'debug' 
      }
    }
  }
};

This configuration means that logs level above error will be output tooh-no-not-again.log and all logs will be output to all-the-logs.log. All properties are as same as log4js except handle property. You can see more configure properties on log4js documentation.

Level

We support the following log level:

• ALL
• ERROR
• WARN
• INFO
• DEBUG

Layout

Console, File and DateFile type supports layout paramter，to decide the output log format, of which value is and object, bellowing is an example:

const path = require('path');
const {File} = require('think-logger3');

module.exports = {
  type: 'file',
  file: {
    handle: File,
    backups: 10,
    absolute: true,
    maxLogSize: 50 * 1024,  //50M
    filename: path.join(think.ROOT_PATH, 'logs/xx.log'),
    layout: {
      type: 'pattern',
      pattern: '%[[%d] [%p]%] - %m',
    }
  }
}

Default Console output format is %[[%d] [%z] [%p]%] - %m, which is [time] [pid] [log level] - log content:

• type：It supports the fellowing types:
  • basic
  • coloured
  • messagePassThrough
  • dummy
  • pattern
  • customize output type refers to Adding your own layouts
  • pattern：output format string, supports the following format parameters
  • %r - .toLocaleTimeString() which look like 下午5:13:04。
  • %p - log level
  • %h - host name
  • %m - log mesage
  • %d - time，default use ISO8601 format，available formats including ISO8601, ISO8601_WITH_TZ_OFFSET, ABSOUTE, DATE or other supported format string, such as %d{DATE} or %d{yyyy/MM/dd-hh.mm.ss}。
  • %% - output % string
  • %n - new line
  • %z - get process ID from process.pid
  • %[ - begin color block
  • %] - end color block

Customize Handle

If you feel that the type of log output provided does not meet your needs, you can implement handle yourself. Custom handle need to achieve the following methods:

module.exports = class {
  /**
   * @param {Object}  config  {}  configurations passed in
   */
  constructor(config) {

  }

  debug() {

  }

  info() {

  }

  warn() {

  }

  error() {

  }
}