Advanced JavaScript logging framework for web- and Node.js applications

TODO: Write short intro

API

Main function

TODO: Write examples

#logs

TODO: Write examples

#defaultOptions

TODO: Write examples

#definePrint()

TODO: Write examples

#dump

TODO: Write examples

#restore

TODO: Write examples

#curry

TODO: Write examples

#define

TODO: Write examples

#defineDefaults

TODO: Write examples

#definePrint

TODO: Write examples

Usage

Basic usage

echo       'You'      # => Level of importance is 0
echo.debug 'are'      # => … is 0
echo.info  'awesome,' # => … is 1
echo.warn  'my'       # => … is 2
echo.error 'friend!'  # => … is 3

echo('Good news!', level: 3)       # => … is 3
echo('Good news!', level: 'error') # => … is 3

Structure of logs:

This code:

echo.log('Test', 'logging', namespace: 'app.lol_module.45')
echo.log(['trololo'])

… will store:

[
  {
    "timestamp":  1341468018606,
    "body":       ["Test", "logging"],
    "namespace":  "app.lol_module.45"
  },
  {
    "timestamp":  1341468018606,
    "body":       [["trololo"]],
    "namespace":  ""
  }
]

Print

By default logs are not printed to developer console (Web Inspector, Firebug etc).

If you want to log with print you should add print: true key:

echo('', print: true)

If you want to setup print: true for specific levels:

echo.definePrint
  0:     false
  3:     true
  error: true

Or you can set advanced rules:

all                                       - Set true to all levels.
only                                      - Set true to only …
except                                    - Set true to all except …
greaterThan (alias: gt)                   - Greater than.
greaterThanOrEqualTo (aliases: gte, gteq) - Greater than or equal to.
lessThan (alias: lt)                      - Less than.
lessThanOrEqualTo (aliases: lte, lteq)    - Less than or equal to.

Examples

Always print:

echo.definePrint('all')

## equal to

echo.definePrint(all: true)

## equal to

echo.defaultOptions.print = true

Only for specific levels:

echo.definePrint('only', [1, 'warn'])

Print log with level great than 4 (except 7 and 9):

echo.definePrint
  gt:     4
  except: [7, 9]

## equal to

echo.definePrint
  gt: 4
  7:  false
  9:  false

## equal to

echo.definePrint
  gt:     4
  except: 7
  9:      false

etc

Print function

By default Echoes use console.log (if defined) for logs with level 0, console.info for 1, console.warn for 2, console.error for 3.

But you can setup your own print function:

ownPrint = (log, options) ->
  alert(log.body)

echo.setPrintFunction(ownPrint)

Log objects (with clone)

All objects and arrays clone on log:

obj =
  qwe: 1
  asd: 2
  obj: qwe: 1, asd: 2

echo obj

loggedObj = echo.logs.first().body[0]

loggedObj == obj     #=> false, because obj was cloned
loggedObj.obj == obj #=> true, but not deeply

Save link to objects instead of clone

If you want to save link to object instead of cloning it, just add clone: false key to options:

obj = qwe: 1, asd: 2

echo obj, clone: false

echo.logs.first().body[0] == obj #=> true

Write plugins for log process

TODO: Add examples

Identify object

There are 3 ways to identify object:

• namespacePrefix
• namespace
• id

On log namespacePrefix, namespace and id join with . and save as cid:

echo 'Qwerty', namespacePrefix: 'app', namespace: 'controller', id: 42
echo.logs.first().cid # => "app.controller.42"

Basic functions to get logs

Get first record:

echo.logs.first()

Get all logs (array of log objects):

echo.logs.all()

Access logs by shortcut

l = echo.logs
l.all()
l.first()

Getters instead functions (works only in [...])

TODO: Add more examples

Grep logs

To find logs with 'some' in body:

echo.logs.grep 'some' # => [{ body: ['Something'] }, { body: ['I want some LSD.']}]

Get logs by time

TODO: Add more examples

Write plugins for logs

TODO: Add more examples

Define custom levels

echo.shitHappened # => undefined
echo.define(shitHappened: 8)
echo.shitHappened # Log function with level of importance equal to 8

Callbacks

TODO: Add examples

Async

TODO: Add examples

Add trace to log (limited support)

TODO: Add examples

Output to browser console

TODO: Add examples

Currying

You can create curried function with predefined options, like level, namespacePrefix etc

Dump log

You can dump logs:

$.post \
  '/logs',
  log: echo.dump()

If you're using an old browser which doesn't have native JSON support (i.e. IE 7), you'll need to include json2.js which adds legacy support.

Dump level

By default dump level is 1:

echo.dump(0)
## => [ { body: [1, 2, "[object Object]"], …

echo.dump()
## => [ { body: [1, 2, { 1, 2, "[object Object]" }], …

echo.dump(2)
## => [ { body: [1, 2, { 1, 2, { 1, 2, "[object Object]" } }], …

## etc

If you want to get deep dump to serialize objects with circular references you should include cycle.js extension to the JSON object and pass -1 as level (be careful, making dump may take a time).

echo.dump(-1)

Restore dump

And restore dump with initializer:

e = Echo(dump)

… or via call restore:

echo.restore(dump)

Store log dumps in local storage

TODO: Add examples

Cleanup logs

TODO: Add examples

Changelog

This project uses Semantic Versioning for release numbering.

Currently this project is in active development but there are no releases yet.

Contributors and sponsorship

Idea and code by @kossnocorp.

Check out full list of contributors.

Initialy sponsored by Evil Martians specially for Wannafun.

License

The MIT License

Copyright (c) 2012 Sasha Koss

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.