loglevelnext
is a modern logging library for Node.js and modern browsers, written with modern patterns and practices which provides log level mapping of the console
object.
For browser use, or use in client-side applications, loglevelnext
should be bundled by your preferred bundler or compiler, such as Rollup.
First thing's first, install the module:
npm install loglevelnext --save
Users can choose to use loglevelnext
in Node.js or in the client (browser).
const log = require('loglevelnext');
log.info('bananas!');
By default loglevelnext
ships supporting the following log level name-value
pairs:
{
TRACE: 0,
DEBUG: 1,
INFO: 2,
WARN: 3,
ERROR: 4,
SILENT: 5
}
When requiring loglevelnext
in Node.js the default export will be an instance of LogLevel
wrapped with some extra sugar.
Please see LogLevel
for documentation of all methods and properties of every log instance, including the default instance.
These methods correspond to the available log levels and accept parameters identical to their console
counterparts. e.g.
console.info('...');
console.info('...');
// ... etc
Returns a new LogLevel
instance. The options
parameter should be an Object
matching the options for the LogLevel
constructor.
Note: LogLevel
instances created are cached. Calling create
with a previously used name
will return the cached LogLevel
instance. To create a different instance with the same name
, assign a unique id
property to the options
parameter.
Type: Array [ Class ]
Returns an Array
containing the factory classes available within loglevelnext
to outside modules. Particularly useful when creating plugins. eg.
const log = require('loglevelnext');
const { MethodFactory } = log.factories;
class MyFactory extends MethodFactory { ... }
Type: Array [ LogLevel ]
Returns an Array
containing references to the currently instantiated loggers.
If you're used to using plugins with loglevel
, fear not. The same capabilities
are available in loglevelnext
, but in a much more straightforward and structured
way. loglevelnext
supports by way of "Factories." A Factory
is nothing more
than a class which defines several base methods that operate on the console
and provide functionality to a LogLevel
instance. All factories must inherit from the
MethodFactory
class, and may override any defined class functions.
For an example factory, please have a look at the PrefixFactory
which provides similar functionality as the loglevel-prefix plugin,
and is the factory which is used when a user passes the prefix
option to a
LogLevel
instance.
As mentioned, loglevelnext
is a logging library for Node.js and modern browsers, which means the latest versions of the major browsers. When bundling or compiling loglevelnext
for use in a browser, you should ensure that appropriate polyfills are used. e.g. Internet Explorer typically requires polyfilling both Symbol
and Object.assign
.
This project originated as a fork of the much-loved loglevel module, but has diverged and has been rewritten, and now shares similarities only in functional intent.
Base Log SVG by Freepik from www.flaticon.com.