atma-logger

Browser and NodeJS Logger

Features:

• string colors: ascii and html

  • object formatters handles circular refs
  • object color theme

• different and extendable Transports

  • Std Console
  • File
  • Http, e.g. Loggly endpoints
  • Stream

• NodeJS: stdout/stderr interceptors

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• Get started

• Logger

• Config

  • Log Levels
  • Log Scopes
  • Transports
    • NodeJS
      • Std
      • File System
        • Example
      • Stream
    • Browser
      • Console
      • Http/Ajax in progress
      • DOMNode output in progress

• Color

• Test

Get started

$ npm i atma-logger -save

// 1. embed
// CommonJS Module
var logger = require('atma-logger'); 				/*minified*/
var logger = require('atma-logger/lib/logger-dev'); /*not minified*/
 
// Exports to `global`
require('atma-logger/lib/global');     /*minified*/
require('atma-logger/lib/global-dev'); /*not minified*/
 
// 2. Configurate (optional). e.g.: File writer
logger.cfg({
    color: 'html',
    logCaller: false,
    logDate: 'dd.MM hh:mm',
    transport: {
        type: 'fs', 
        extension: 'html',
        directory: 'logs/'
    }
});
 
// 3.0 Global logger, e.g:
logger
    .log('Foo, {0}!', 'Baz')
    .error('Global:', global);
 
// 3.1 Scope logger, e.g:
var QuxLog = logger.create('Qux', logger.level_DEBUG);
QuxLog('lorem');
QuxLog.error('lorem');
 
// won't log if global loglevel ist lower than 'debug'.
// to force Qux logs to be printed override the log level of `Qux` logger
// and set some small level:
logger.cfg('levels',{
    'Qux': logger.level_WARN
    // same as:
    'Qux': 25
})
 
// oder start app with overriden level:
$ node myapp --level.Qux 25
 

<!-- Browser -->
<script src='lib/browser.min.js'></script>
<script>
// same usage as with NodeJS:
logger.cfg(ConfigurationObject)
logger.log(...args);
</script> 

Logger

Logger = Function
    // if level is greater than current global level `EmptyLogger` is returned
    - function(level):Logger | EmptyLogger
    // is for assertion logs
    - function(Boolean):Logger |EmptyLogger
    
Logger __static__ AND __proto__ {
    // Logger functions. They all have different default log levels.
    //   Global default level is level_LOG
    // accept any arguments
    // returns self
    log:   function(...args):Self
    warn:  function(...args):Self
    error: function(...args):Self
    trace: function(...args):Self
    debug: function(...args):Self
    
    // Creates scoped Logger
    // - name: is also printed
    // - level: custom log level for this scope.
    //    Caution: You can overwrite this with configuration
    // returns Log function with Logger in static
    
    create: function(name:String [,? level:Number]):Function<Logger>
    
    cfg : Function
        - function(key:String, value:Any):Self
        - function(CfgObject:Object):Self
        - function(key:String):Any /*value*/
    
    // const
    level_ERROR: 0
    level_WARN:  25
    level_LOG:   50
    level_DEBUG: 75
    level_TRACE: 100
}

Usage examples:

logger.log('Global object:', global);
 
var log1 = logger.create('foo');
log1('Hello'); //> foo Hello
 
var log2 = log1.create('baz');
log2('Hello'); //> foo.baz Hello
log2.warn('Hello'); //> foo.baz Hello

Configuration

CfgObject {
    // global log level, default is level_LOG === 50
    level: Number
    
    // override log levels for scoped loggers
    levels: ScopeLevels<Object>
    
    // @default: NodeJS: ascii, Browser: none
    color: 'none|ascii|html'
    
    /** Format message as a string before the output,
      * otherwise raw arguments are passed to the transport
      * Features:
      *   - printf style
      *   - format Arrays and Objects(circular refs are handled)
      *   - format Number, Data, RegExp, etc.
     \*/
    formatMessage: true,
    
    // log the filename and the linenumber
    // @default: true
    logCaller: Boolean
    
    // uncaughtExceptions: flush the error and exit the process
    // @default: false
    handleExceptions: Boolean,
    
    // Date format pattern. e.g: 'dd-MM hh:mm'
    // @default: ''
    logDate: String
    
    // Define any custom function,
    // which returns some string, that should be prepended to the message
    // Can be used to add ANY info to the message, 	
    // @default: null
    logMeta: Function,
    
    transport: TransportConfig
}

Log Levels

Logger performs prints only, if current level is smaller than loggers level or per instance(scope) level. Default level is level_LOG === 50, so logger.trace(something) will do nothing.

logger.cfg({
    // override global level
    level: Number,
    
    // extends current scope levels
    levels: ScopeLevels<Object>
})
ScopeLevels {
    // strict scoped level
    'scopeName': Number,
    
    // strict for sub scope
    'baz.qux': Number,
    
    // self and all sub scopes
    'scopeName.*': Number
    
    // or even deeper
    'scopeName.foo.*': Number
}

Example:

/*
 * Global levels
\*/
 
// predefined
logger.debug('foo') //> does nothing
logger.cfg({ level: logger.level_DEBUG /*75*/ })
logger.debug('foo') //> prints foo
 
// custom
logger(90).log('foo') //> does nothing, as `90` is greater then level_DEBUG with `75`
logger.cfg({ level: 90 });
logger(90).log('foo') //> prints foo
 
logger.cfg({ level: -1 });
// even errors wont be printed
logger.error('foo') //> does nothing
 
 
/*
 * Scoped instance
\*/
 
var userServiceLogger = logger('userService', 25);
 
// prints nothing, as level_LOG === 50 is required
userServiceLogger('baz') //same as userServiceLogger.log('baz');
 
// Turn `userService` logging on via configuration
logger.cfg({
    levels: {
        // enable logs
        'userService': 50,
        
        // enable traces
        'userService.patch': 100
    }
});
userServiceLogger('baz') // prints baz
 
var userPatcherLogger = userServiceLogger.create('patch');
userPatcherLogger.trace(user) // prints user object

Transports

Std

NodeJS default. Print logs to the console

STD_TransportConifg = {
    type: 'std'
};

File System

Async file-system transport with buffering.

FS_TransportConfig = {
    type: 'fs',
    
    // defaults
    extension: 'txt', 
    directory: 'logs/',
    
    // message COUNT to buffer before write
    // @default, is NO buffering
    bufferSize: 0,
    
    // in Bytes
    fileSize: 500 * 1024,
    
    // After the filesize is reached its maximum, a new file will be created
    // This option limits the log files. Old log files will be deleted
    filesCount: 10,
    
    // all writes are async, but to switch to sync writes set this option to `true`
    sync: false,
    
    // when set to `true` then all std writes, like - console.log,
    // will be also written to the file system.
    interceptStd: false
};

FS Example

logger.cfg({
    logCaller: true,
    logDate: 'hh:mm',
    transport: {
        type: 'fs',
        interceptStd: true
    }
});
logger.log('Hello');
 
// will be also catched and written to the file
console.log('World')
 
// Now go to the `logs` directory in the current working directory, and see the output:
// something like:
'08:59 Hello (at main.js:10)'
'08:59 World (at main.js:13)'

Http

Write logs to http endpoint,

Http_TransportConfig {
    type: 'http',
    // Upload URL
    url: 'URL',
    
    // Message COUNT to buffer before upload
    bufferSize: 0,
    
    // default:
    method: 'POST'
    
    // default: 
    headers: { 'Content-Type': 'text/plain' }
}

// Browser: There is image technique to upload logs to the cross-origin endpoint.
// Logger will automatically match the image extension from url, and will use this technique instead of `XMLHttpRequest`
// e.g.
Logger.cfg({
    transport: {
        type: 'http',
        url: 'http://logs-01.loggly.com/bulk/token.gif?PLAINTEXT='
    }
})

Stream

Provide any Writable stream, and all logs are piped to that stream

Stream_TransportConfig {
    type: 'stream',
    stream: IWritableStream
}
// e.g
logger.cfg({
    transport: {
        type: 'stream',
        stream: FooSocket
    }
});

Colorize string

HTML and ASCII colors are supports (refer to color option).

 
    String.prototype
        .red
        .green
        .yellow
        .blue
        .magenta
        .cyan
        
        .bg_black,
        .bg_red,
        .bg_green,
        .bg_yellow,
        .bg_blue,
        .bg_magenta,
        .bg_cyan,
        .bg_white,
        
        .bold
        .italic
        .underline
        .inverse
        ;
 
    'green<bold<lorem> ipsum>'.color

Test

$ npm install
$ npm test

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© MIT Atma.js Project