tracer

#tracer for node.js

A powerful and customizable logging library for node.js.

=========== ##Features

• print log messages with timstamp, file name, method name, line number, path or call stack
• be customized output format with micro-template and timestamp format
• support user-defined logging levels
• add easily any transport
• support filter functions, so print statements in full color and font (color console)

##Install

npm install tracer

Usage

Add to your code:

Simple Console

var logger = require('tracer').console();

Color Console

var logger = require('tracer').colorConsole();

Set Output Level

var logger = require('tracer').colorConsole({level:'warn'});

Simple Example

Simple Console

var logger = require('tracer').console();

logger.log('hello');
logger.trace('hello', 'world');
logger.debug('hello %s',  'world', 123);
logger.info('hello %s %d',  'world', 123, {foo:'bar'});
logger.warn('hello %s %d %j', 'world', 123, {foo:'bar'});
logger.error('hello %s %d %j', 'world', 123, {foo:'bar'}, [1, 2, 3, 4], Object);

$ node example/console.js 
2012-03-02T13:35:22.83Z <log> console.js:3 (Object.<anonymous>) hello
2012-03-02T13:35:22.85Z <trace> console.js:4 (Object.<anonymous>) hello world
2012-03-02T13:35:22.85Z <debug> console.js:5 (Object.<anonymous>) hello world 123
2012-03-02T13:35:22.85Z <info> console.js:6 (Object.<anonymous>) hello world 123 { foo: 'bar' }
2012-03-02T13:35:22.85Z <warn> console.js:7 (Object.<anonymous>) hello world 123 {"foo":"bar"}
2012-03-02T13:35:22.85Z <error> console.js:8 (Object.<anonymous>) hello world 123 {"foo":"bar"} [ 1, 2, 3, 4 ] function Object() { [native code] }

Color Console

var logger = require('tracer').colorConsole();

logger.log('hello');
logger.trace('hello', 'world');
logger.debug('hello %s',  'world', 123);
logger.info('hello %s %d',  'world', 123, {foo:'bar'});
logger.warn('hello %s %d %j', 'world', 123, {foo:'bar'});
logger.error('hello %s %d %j', 'world', 123, {foo:'bar'}, [1, 2, 3, 4], Object);

Daily Log

var logger = require('tracer').dailyfile({root:'.'});

logger.log('hello');
logger.trace('hello', 'world');
logger.debug('hello %s',  'world', 123);
logger.info('hello %s %d',  'world', 123, {foo:'bar'});
logger.warn('hello %s %d %j', 'world', 123, {foo:'bar'});
logger.error('hello %s %d %j', 'world', 123, {foo:'bar'}, [1, 2, 3, 4], Object);

dailylog will output all types log to diff files every day like log4j

Advanced Example

some helper package is need, so install -dev for running examples

npm install -dev tracer

Take a look at the examples directory for different examples.

Set logging level

the level option support index (number) or method name.

var logger = require('tracer').console({level:'warn'});

equal

var logger = require('tracer').console({level:4});

var logger = require('tracer').console({level:'warn'});
logger.log('hello');
logger.trace('hello', 'world');
logger.debug('hello %s',  'world', 123);
logger.info('hello %s %d',  'world', 123, {foo:'bar'});
logger.warn('hello %s %d %j', 'world', 123, {foo:'bar'});
logger.error('hello %s %d %j', 'world', 123, {foo:'bar'}, [1, 2, 3, 4], Object);

//$ node example/level.js 
//2012-03-02T13:41:33.29Z <warn> level.js:6 (Object.<anonymous>) hello world 123 {"foo":"bar"}
//2012-03-02T13:41:33.30Z <error> level.js:7 (Object.<anonymous>) hello world 123 {"foo":"bar"} [ 1, 2, 3, 4 ] function Object() { [native code] }

//log,trace, debug and info level was not ouputed 

Customize output format

format tag:

• timestamp: current time
• title: method name, default is 'log', 'trace', 'debug', 'info', 'warn', 'error'
• level: method level, default is 'log':0, 'trace':1, 'debug':2, 'info':3, 'warn':4, 'error':5
• message: printf message, support %s string, %d number, %j JSON and auto inspect
• file: file name
• line: line number
• pos: postion
• path: file's path
• method: method name of caller
• stack: call stack message

we use tinytim micro-template system to output log. see details tinytim.
and, we use Date Format to format datetime.

var logger = require('tracer').console(
				{
					format : "{{timestamp}} <{{title}}> {{message}} (in {{file}}:{{line}})",
					dateformat : "HH:MM:ss.L"
				});

Or, you can set special format for output method

var logger = require('tracer')
		.colorConsole(
				{
					format : [
					          "{{timestamp}} <{{title}}> {{message}} (in {{file}}:{{line}})", //default format
					          {
					        	  error : "{{timestamp}} <{{title}}> {{message}} (in {{file}}:{{line}})\nCall Stack:\n{{stack}}" // error format
					          }	
					],
					dateformat : "HH:MM:ss.L",
					preprocess :  function(data){
						data.title = data.title.toUpperCase();
					}
				});

the preprocess method is a choice for changing tag.

Customize output methods

var colors = require('colors');

var logger = require('tracer').colorConsole({
	level : 'log1',
	methods : [ 'log0', 'log1', 'log2', 'log3', 'log4', 'log5' ],
	filters : [colors.underline, colors.yellow],

});
logger.log0('hello');
logger.log1('hello', 'world');
logger.log2('hello %s', 'world', 123);
logger.log4('hello %s %d', 'world', 123);
logger.log5('hello %s %d', 'world', 123);

Customize filters

each filtes function was called. the function is synchronous and must be like

function f1(str) {
	return str.toUpperCase();
}

or you can use the second parameter

function f1(str, data) {
	if( data.title === 'error' ){
		//do some thing, example write to database, you can use async write to do this
		
		//if you don't want continue other filter, then 
		//return false; 
	}
	return str.toUpperCase();
}

About Colors.js

var colors = require('colors');
var logger = require('tracer').colorConsole({
	filters : [
	           f1, colors.underline, colors.blue, //default filter
	           //the last item can be custom filter. here is "warn" and "error" filter
	           {
	        	   warn : colors.yellow,
	        	   error : [f1, colors.red, colors.bold ]
	           }
	]
});

the filter support key-function pair, example: color_console.js

{
		filters : {
			//log : colors.black,
			trace : colors.magenta,
			debug : colors.blue,
			info : colors.green,
			warn : colors.yellow,
			error : [ colors.red, colors.bold ]
		}
}

and the filters is an array, the last item can be custom filter. see example:filter.js

Log File Transport

var fs = require('fs');

var logger = require('tracer').console({
	transport : function(data) {
		console.log(data.output);
		fs.open('./file.log', 'a', 0666, function(e, id) {
			fs.write(id, data.output+"\n", null, 'utf8', function() {
				fs.close(id, function() {
				});
			});
		});
	}
});

logger.log('hello');
logger.trace('hello', 'world');
logger.debug('hello %s', 'world', 123);
logger.info('hello %s %d', 'world', 123, {foo : 'bar'});
logger.warn('hello %s %d %j', 'world', 123, {foo : 'bar'});
logger.error('hello %s %d %j', 'world', 123, {foo : 'bar'}, [ 1, 2, 3, 4 ], Object);

Stream Transport

var fs = require('fs');

var logger = require('tracer').console({
		transport : function(data) {
			console.log(data.output);
			var stream = fs.createWriteStream("./stream.log", {
			    flags: "a",
			    encoding: "utf8",
			    mode: 0666
			}).write(data.output+"\n");
		}
});

logger.log('hello');
logger.trace('hello', 'world');
logger.debug('hello %s',  'world', 123);
logger.info('hello %s %d',  'world', 123, {foo:'bar'});
logger.warn('hello %s %d %j', 'world', 123, {foo:'bar'});
logger.error('hello %s %d %j', 'world', 123, {foo:'bar'}, [1, 2, 3, 4], Object);

MongoDB Transport

var mongo = require('mongoskin');
var db = mongo.db("127.0.0.1:27017/test?auto_reconnect");

var log_conf = {
		transport : function(data) {
			console.log(data.output);
			var loginfo = db.collection("loginfo");
			loginfo.insert( data, function(err, log) {
				if (err) {
					console.error(err);
				}
			});
		}
}

var logger = require('tracer').console(log_conf);

logger.log('hello');
logger.trace('hello', 'world');
logger.debug('hello %s',  'world', 123);
logger.info('hello %s %d',  'world', 123, {foo:'bar'});
logger.warn('hello %s %d %j', 'world', 123, {foo:'bar'});
logger.error('hello %s %d %j', 'world', 123, {foo:'bar'}, [1, 2, 3, 4], Object);

console.log('\n\n\npress ctrl-c to exit');

Define your logging helper

the work is like color_console.js

var colors = require('colors');
module.exports = function(conf) {
	return require('./console')({
		filters : {
			//log : colors.black,
			trace : colors.magenta,
			debug : colors.blue,
			info : colors.green,
			warn : colors.yellow,
			error : [ colors.red, colors.bold ]
		}
	}, conf);
};

Customize output Object's properties

var obj =  {Request: 
   [ { IsValid: [ 'True' ],
       ItemSearchRequest: 
        [ { ResponseGroup: [ 'Small', 'OfferSummary' ],
            Sort: [ 'salesrank' ],
            SearchIndex: [ 'DVD']
          }
        ]
     } ] };
     
var logger = require('tracer').console({
		showHidden : true, //the object's non-enumerable properties will be shown too
		depth : null //tells inspect how many times to recurse while formatting the object. This is useful for inspecting large complicated objects. Defaults to 2. To make it recurse indefinitely pass null.
	});
logger.log(obj);

// 
// 2013-09-30T04:30:44.927Z <log> depth.js:26 (Object.<anonymous>) { Request:
//    [ { IsValid: [ 'True', [length]: 1 ],
//        ItemSearchRequest:
//         [ { ResponseGroup: [ 'Small', 'OfferSummary', [length]: 2 ],
//             Sort: [ 'salesrank', [length]: 1 ],
//             SearchIndex: [ 'DVD', [length]: 1 ] },
//           [length]: 1 ] },
//      [length]: 1 ] }
     

History

0.6.2

• fixed: change stack from array to string, and fixed example2.js

0.6.1

• fixed: get the filename correctly on windows. thanks Tom Carchrae
• added: added missing repository field. thanks madarche

0.6.0

• feature: add showHidden and depth option for showing object's properties.

0.5.1

• feature: add args into data object, now we can check args in preprocess, see example format2.js, merge from yasuyk04/work

0.5.0

• performance: speed up when the format don't include method,path,line,pos,file, thanks sharonjl's issue report

0.4.2

• fixed: debug color from blue to cyan

0.4.1

• fixed: default timestamp is ISO UTC format.

0.4.0

• feature: support dailyfile method, added some examples
• feature: add preprocess custom method for changing tags before format

0.3.5

• fixed bug: can't get method/line number in express

0.3.4

• use tinytim package

0.3.3

• spell missing (transpot->transport)

0.3.2

• speed-up for _log function
• add some test codes

0.3.1

• minor-fix for call stack

0.3.0

• support custom format and filter for special method

0.2.1

• fix spell missing

0.2.0

• Add more examples.
• Default methods is log, trace, debug, info, warn, error.
• Support 'string' level, {level:'warn'} equal {level:4}

0.1.0

• Initial Tracer implementation.

License

(The MIT License)

Copyright (c) 2012 LI Long <[e-mail]>

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.