https://github.com/ud-ud/simple-logger
Simple logger with module-specific instances and log format strings
https://github.com/ud-ud/simple-logger
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Simple logger with module-specific instances and log format strings
- Host: GitHub
- URL: https://github.com/ud-ud/simple-logger
- Owner: UD-UD
- Created: 2018-05-07T13:32:40.000Z (almost 7 years ago)
- Default Branch: master
- Last Pushed: 2018-05-09T11:28:06.000Z (almost 7 years ago)
- Last Synced: 2025-02-16T07:17:51.480Z (3 months ago)
- Topics: logging
- Language: TypeScript
- Homepage:
- Size: 92.8 KB
- Stars: 0
- Watchers: 2
- Forks: 0
- Open Issues: 1
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Metadata Files:
- Readme: Readme.md
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README
# Simple Logger
## API Usage
```js
import { SimpleLogger, LogLevel } from 'simple-logger';
const l = new SimpleLogger('testModule');
// Log methods
l.log('message'); // 10:40:50::testModule::LOG:: message
l.debug('message'); // 10:40:50::testModule::DEBUG:: message
l.warn('message'); // 10:40:50::testModule::WARN:: message
l.error('message'); // 10:40:50::testModule::ERROR:: message
// Change format string
l.setFormatString('Module is: {module} - {message} - at time {HH}:{MM}:{ss}');
l.debug('Hello world'); // Module is: testModule - Hello world - at time 11:48:57
// Change log level
SimpleLogger.setLogLevel(LogLevel.warn);
l.debug('Hello world'); // No log
// Reset log level
SimpleLogger.resetLogLevel();
```
Details of the string which can be passed into `setFormatString` is described below.
### Format string specs
We are using two libraries called `string-format` and `dateformat`.
#### [string-format](https://github.com/davidchambers/string-format) -
We use this for the template string syntax. It allows quite a few syntaxes, but we are using the simple object destructuring syntax, which is shown in the first example [here](https://github.com/davidchambers/string-format#string-format).
To explain it simply, the formatting string looks like `"Hello Mr.{key1} - Welcome to {key2}"` and the values of this keys will be replaced with those from the formatting object. Invalid keys will create empty replacement string.
We pass in a formatting object with these keys:
1. `module` - Module name, passed in the Logger constructor.
2. `message` - String passed in log / warn / error methods.
3. `logLevel` - Log level in upper case, eg. DEBUG.
4. Timestamp related keys - Documented below
Default format string is `'{HH}:{MM}:{ss}::{module}::{logLevel}:: {message}'`
#### [dateformat](https://www.npmjs.com/package/dateformat) -
Using this library, we create many time related keys, which are mostly equivalent to what is documented in [mask options](https://www.npmjs.com/package/dateformat#mask-options) and [named formats](https://www.npmjs.com/package/dateformat#named-formats).
What is slightly different from the above documentation is that we don't support `N`, `o`, `S`, `Z` and `UTC:` as they act as modifiers and don't make much sense as individual keys.
Some examples of supported date format strings are:
1. `"{default}"` - Sat Jun 09 2007 17:46:21
2. `"{HH}:{MM}:{ss}"` - 11:48:57
3. `"{shortDate} ({W}th week of the year)"` - 6/9/07 (34th week of the year)