Logr the full stack JavaScript dynamic console logger.
Logr is a console logging replacement for JavaScript that runs on the client, server or both. Logr supports some innovative features for reducing the amount of boilerplate logging by allowing you to dynamically trace JavaScript methods and output each function call at runtime.
- Use the same logger for both client and server JavaScript code
- Dynamically trace any JavaScript objects
ownedmethods usinglogInstance.attach(obj) - Get the real line numbers of called functions
- Organize and group your logs using Logr's log instances
- Programaticaly set logging levels globally or per log
- Chrome extension for easily managing runtime instance logs
- Logging levels are stored per session (on the client) allowing you to turn logging on and off in QA and Staging environments and have them stored for the entire browsing session
- AMD and CommonJS compatible
bower install logr.jsnpm install logr.jsI've created a simple chrome extension for easily changing logging levels at from devtools.
https://chrome.google.com/webstore/detail/logr/baeanbiibajakocmgnnoadgljmnknonp
Logr can be added in either the head or before the closing body tag.
<body>
<script src='bower_components/logr.js/logr.js'></script>
</body>Logr may also be used via AMD
define(['logr'], function(Logr){})Logr may also be used via CommonJS require
var Logr = require('logr.js');Logr internally manages logging instances. Using the Logr.log method will
return an existing logging instance of the same name or create you one.
var log = Logr.log('foo'); // creates a logging instance of the name fooLogr proxies the the real console methods are that are shared between Node's global console object and modern web browers.
log.log("nothing to see here just debugging", {foo: 'baz'});log.info("nothing to see here just sending some information", {foo: 'baz'});log.warn("nothing to see here just warning you", {foo: 'baz'});log.error("nothing to see here just the sky is falling", {foo: 'baz'});The reason I created Logr was that I wanted to avoid having to write the same boilerplate object method logging over and over again. It's verbose, ugly and difficult to manage. What I wanted was a way for all the methods on my objects to be automatically wrapped in console statements outputting their inputs, outputs, order of execution and so on.
Take for example this simple dog API.
var dog = {
bark: function() {
console.log('bark bark!');
},
run: function(name) {
console.log(name + ' runs around');
},
eat: function(name, food) {
console.log(name + ' eats' + food);
},
today: function() {
this.bark();
this.run("rocket");
this.eat("rocket", "all the things");
}
}We start by creating a log and then attaching the dog object to our logger.
var dogLog = Logr.log('dog');
dogLog.attach(dog);Finally we call a method on the dog object.
dog.bark(); // bark() is executed wrapped in a console grouping statementWhich in your webkit/gecko console will output the following.
To see a more sophisticated example we can call the today method which in turns
calls several other methods on the dog object.
dog.today();
By default all Logr logging instances are created with a logging level of LOG meaning all
logging messages will reach your browsers console. You can override this by passing a level in the options
during log instance creation.
var log = Logr.log('foo', { level: Logr.levels.ERROR }); // set the logger level to error and aboveNote: all object logging is automatically set the debug level.
Calling Logr.setLevel will set the session based logging level for all stored instances. You should only call this from
your browser to overwrite the initial level state.
Logr.setLevel(Logr.levels.NONE); // no messages get through
Logr.setLevel(Logr.levels.LOG); // only debug messages
Logr.setLevel(Logr.levels.INFO); // debug and info messages
Logr.setLevel(Logr.levels.WARN); // debug, info and warn messages
Logr.setLevel(Logr.levels.ERROR); // all messagesTo set the session based logging level for a single instance simply call setLevel on that instance.
var log1 = Logr.log('log1');
log1.setLevel(Logr.levels.NONE); // no messages get through
log1.setLevel(Logr.levels.LOG); // only debug messages
log1.setLevel(Logr.levels.INFO); // debug and info messages
log1.setLevel(Logr.levels.WARN); // debug, info and warn messages
log1.setLevel(Logr.levels.ERROR); // all messagesAll log levels are stored in your browsers sessionStorage meaning changes to Logr's levels will persist until the end of the browser session. This is useful in cases where you want to turn on and off logging levels in QA/Integration environment or simply filter your debugging logs down while working.
You can for example set your all of your logs to ERROR by default and lower their levels
from your browser to avoid log overload.
Example:
Say that I create three logs foo, baz, and bar. By default I set all their
levels to ERROR only.
var foo = Logr.log('foo', { level: Logr.levels.ERROR });
var baz = Logr.log('baz', { level: Logr.levels.ERROR });
var bar = Logr.log('bar', { level: Logr.levels.ERROR });
foo.attach(dog); // not seen as objects are always on LOG level
foo.warn('foo is getting angry'); // not seen
foo.error('foo is blowing up'); // seenIf at some point in the future I needed to see INFO, WARN or LOG messages
I could set that globally or per log.
In Chrome/Firefox's javascript console I could type the following.
Logr.log('foo').setLevel(Logr.levels.LOG); // sets foo log to LOG levelor
Logr.setLevel(Logr.levels.LOG); // sets all logs to LOG levelFork the repo and issue a pull request
The MIT License
Copyright (c) 2014 Eric Clifford
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.