1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
|
<div align="center">
<img width="150" height="150" src="http://shellscape.org/assets/images/external/loglevelnext-icon.svg">
</div>
[![npm][npm]][npm-url]
[![node][node]][node-url]
[![devdeps][devdeps]][devdeps-url]
[![tests][tests]][tests-url]
[![coverage][cover]][cover-url]
# loglevelnext
`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.
## Getting Started
First thing's first, install the module:
```console
npm install loglevelnext --save
```
## Usage
Users can choose to use `loglevelnext` in Node.js or in the client (browser).
```js
// Node.js
const log = require('loglevelnext');
log.info('bananas!');
```
```html
<!-- browser -->
<!doctype>
<html>
<head>
<script src="/path/to/loglevelnext.js"></script>
</head>
<body>
<script>
window.log.info('zomg');
</script>
</body>
</html>
```
## Log Levels
By default `loglevelnext` ships supporting the following log level name-value
pairs:
```js
{
TRACE: 0,
DEBUG: 1,
INFO: 2,
WARN: 3,
ERROR: 4,
SILENT: 5
}
```
## Default Logger
When requiring `loglevelnext` in Node.js the default export will be an instance
of [`LogLevel`](docs/LogLevel.md) wrapped with some extra sugar.
When loading the `loglevelnext.js` script in the client (browser), the script
will assign `window.log` to an instance of [`LogLevel`](docs/LogLevel.md),
wrapped with that same extra sugar.
### Methods
Please see [`LogLevel`](docs/LogLevel.md) for documentation of all methods and
properties of every log instance, including the default instance.
#### `trace`, `debug`, `info`, `warn`, `error`
These methods correspond to the available log levels and accept parameters
identical to their `console` counterparts. eg.
```js
console.info('...');
console.info('...');
// ... etc
```
#### `getLogger(options)`
Returns a new `LogLevel` instance. The `options` parameter should be an `Object`
matching the options for the [`LogLevel`](docs/LogLevel.md) constructor.
_Note: the logger returned is cached, and subsequent requests for a logger of
the same name will return the same logger instance. If you require multiple
unique loggers of the same name, pass an `id` property with a unique identifier
and `getLogger` will use that over the `name`._
#### `noConflict()`
When using `loglevelnext` in a browser environment, you may encounter a scenario
in which `window.log` is already assigned when the script loads, resulting in
`window.log` being reassigned to `loglevelnext`. This method will restore
`window.log` to it's original value and return the default logger.
### Properties
#### `factories`
Type: `Array [ Class ]`
Gets an `Array` containing the factory classes available within `loglevelnext`
to outside modules. Particularily useful when creating plugins. eg.
```js
const log = require('loglevelnext');
const { MethodFactory } = log.factories;
class MyFactory extends MethodFactory { ... }
```
#### `loggers`
Type: `Array [ LogLevel ]`
Gets an `Array` containing references to the currently instantiated loggers.
## Factories aka Plugins
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`][methodFactory] class, and may override any defined class functions.
For an example factory, please have a look at the [`PrefixFactory`][prefixFactory]
which provides similar functionality as the [loglevel-prefix](loglevelpre) plugin,
and is the factory which is used when a user passes the `prefix` option to a
`LogLevel` instance.
## Persisting the Level
Persisting the level of a log between sessions in a browser isn't the job of a
logging library. Primarily because working with `localStorage` these days is a
breeze. If you need to store and retrieve a log level value between sessions,
please look into leveraging the excellent and very tiny [`store2`](https://github.com/nbubna/store)
library.
## Browser Support
As mentioned, `loglevelnext` is a logging library for Node.js and _modern_
browsers, which means the latest versions of the major browsers. Unfortunately
"oldIE" versions aren't officially supported. The minimum Internet Exploder
version supported is IE10, though [Microsoft no longer supports it][oldie].
If you're in need of support for old or outdated browser versions, please use
the older [loglevel][loglevel], which supports browsers as old as IE6.
_Note: This library's distribution file is compiled in a way that will
technically work all the way back to IE8 - as that version and above support
`localStorage`. However, IE8 and IE9 require that the developer tools be open
prior to invoking this library._
## Contributing
We welcome your contributions! Please have a read of [CONTRIBUTING.md](CONTRIBUTING.md) for more information on how to get involved.
## Attribution
_This project is a fork of the much-loved [loglevel](loglevel) module._
Base Log SVG by [Freepik](http://www.freepik.com/) from [www.flaticon.com](http://www.flaticon.com).
## License
#### [MIT](./LICENSE)
[npm]: https://img.shields.io/npm/v/loglevelnext.svg
[npm-url]: https://npmjs.com/package/loglevelnext
[node]: https://img.shields.io/node/v/loglevelnext.svg
[node-url]: https://nodejs.org
[deps]: https://david-dm.org/shellscape/loglevelnext.svg
[deps-url]: https://david-dm.org/shellscape/loglevelnext
[devdeps]: https://david-dm.org/shellscape/loglevelnext/dev-status.svg
[devdeps-url]: https://david-dm.org/shellscape/loglevelnext
[tests]: http://img.shields.io/travis/shellscape/loglevelnext.svg
[tests-url]: https://travis-ci.org/shellscape/loglevelnext
[cover]: https://codecov.io/gh/shellscape/loglevelnext/branch/master/graph/badge.svg
[cover-url]: https://codecov.io/gh/shellscape/loglevelnext
[loglevel]: https://githhub.com/pimterry/loglevel
[loglevelpre]: https://github.com/kutuluk/loglevel-plugin-prefix
[oldie]: https://www.microsoft.com/en-us/windowsforbusiness/end-of-ie-support
[methodFactory]: lib/MethodFactory.js
[prefixFactory]: factory/PrefixFactory.js
|
