https://github.com/xeinebiu/typescript_logger
Enable logging on your TS Project using decorators|annotations.
https://github.com/xeinebiu/typescript_logger
console decorators filter javascript logger logging logs typescript
Last synced: about 1 month ago
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Enable logging on your TS Project using decorators|annotations.
- Host: GitHub
- URL: https://github.com/xeinebiu/typescript_logger
- Owner: xeinebiu
- Created: 2020-04-26T20:02:22.000Z (about 6 years ago)
- Default Branch: master
- Last Pushed: 2021-09-12T16:12:19.000Z (almost 5 years ago)
- Last Synced: 2025-09-30T01:50:31.791Z (9 months ago)
- Topics: console, decorators, filter, javascript, logger, logging, logs, typescript
- Language: TypeScript
- Homepage:
- Size: 117 KB
- Stars: 1
- Watchers: 1
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
## Logger for Typescript
Enable logging on your TS Project using decorators|annotations.
---
### Installation
````bash
npm i @xeinebiu/ts-logger@1.1.2
````
---
### Change Logs
1.1.1
- Export LogClass
1.1.0
- Add LogClass Decorator
1.0.1
- Fix module exports
1.0.0
- Initial Version
### Usage
---
#### Logger
Setting the ``listner`` is necessary to enable the logging.
````javascript
Logger.listener = {
// Return True to output the given [log], false otherwise
beforeLog: (log: Log, outputType: OutputType) => {
return true;
},
// The given [log] is printed
afterLog: (log: Log, outputType: OutputType) => {
},
// Apply different styles of [Log] and [outputType]
applyStyle: (log: Log, outputType: OutputType) => {
if (outputType === OutputType.log) {
return 'background: #8c7ae6; color: #2f3640; padding: 3px';
}
return true;
}
};
````
---
#### Method Logger
To log any method, use ``@Method.Log()`` decorator and `@Method.asyncLong()` for Asynchronous Methods.
Assume we have a class called ``Demo`` and we want to log some methods on it.
````javascript
class Demo {
@Method.log()
public add(...args: number[]): number {
let sum = 0;
args.forEach(x => sum += x);
return sum;
}
}
````
Now, every time the method ``add(..args)`` is invoked, an output will result in console like the below
##### MethodLoggerOptions
The decorator ``@Method.log()`` accepts an `MethodLoggerOptions` as single argument where we can configure the Logger
for each Method.
````javascript
@Method.log({tag: 'Sum collection of numbers', args: true, importance: 1, printResult: true})
public add(...args : number[]) : number {
let sum = 0;
args.forEach(x => sum += x);
return sum;
}
````
With the above configuration, we are about to see 2 logs for the same method call. First Log when the method is invoked,
and the second when Return.
Arguments can be printed partially also.
````javascript
@Method.asyncLog({tag: 'Login', printResult: true, args: [0]})
public login(username : string, password : string ): Promise < boolean > {
return new Promise < boolean > ((resolve) => {
setTimeout(() => resolve(true), 1000);
});
}
````
---
##### Injector
Injector can be used when Logging from inside of method is needed. Inject as last argument, the ``Logger`` and set it
to `optional`.
````javascript
@Method.log({inject: true})
public add(args : number[], logger? : Logger) : number {
logger.debug('Add method is called');
let sum = 0;
args.forEach(x => sum += x);
logger.params.data.result = sum;
logger.debug(`Total: ${sum}`);
return sum;
}
````
#### Filter
Filter of logs can be done from the Listener ``beforeLog()`` callback.
````javascript
beforeLog: (log: Log, outputType: OutputType) => {
return log.data.importance ! > 2 && outputType === OutputType.debug;
},
...
````
> Outputs only the Logs with importance greater than ``2`` and of type `debug`
````javascript
beforeLog: (log: Log, outputType: OutputType) => {
return log.data.tag === 'login';
},
...
````
> Outputs only the logs with the Tag `login`
Depending on your needs, filter can be done on many ways as it needed.
### Author
> xeinebiu