LGN-Log/README.md

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# LGNLog
A custom logger implementation and [TaskLocal](https://developer.apple.com/documentation/swift/tasklocal?language=swift)
helper for [Swift-Log](https://github.com/apple/swift-log).
# Why and how
This package provides two and a half things (and a small bonus):
* TaskLocal support for `Logger` struct
* A custom (and a pretty one) log handler implementation
* Also it does `import Logging` so you don't have to (.mp4), just import `LGNLog` and it will work
## TaskLocal
As per this package `Logger` now has `@TaskLocal var current` property which does precisely what you think it does:
your app can call `Logger.current` in every place you can imagine to get a current logger, and you shouldn't bother
creating new temporary loggers here and there. By default it's just a simple logger with label `default`.
Sure enough, you can bind it to your configured logger for some async `Task` just like that:
```swift
var logger = Logger(label: "custom_label")
logger[metadataKey: "requestID"] = "\(UUID())"
logger[metadataKey: "FileLine"] = "main.swift:322"
Logger.$current.withValue(logger) {
Logger.current.info("hello")
}
```
And there you have it.
## Custom implementation
Of course, default formatting isn't very pretty:
`
2021-10-23T17:51:14+0300 info custom_label : FileLine=main.swift:322 requestID=00000000-1637-0034-1711-000000000000 Hello
`
so this package comes with a prettier formatting. You can enable it by calling:
```swift
LoggingSystem.bootstrap(LGNLogger.init)
```
Et voilà:
`
[2021-10-24 13:01:57 +0000 @ main.swift:322] [custom_label] [info] [00000000-1637-0034-1711-000000000000]: Hello (metadata: {"FileLine":"main.swift:322"})
`
Additionally, it has a few config vars:
### Sets a log level globally for all loggers initiated with this backend (`.info` by default):
```swift
LGNLogger.logLevel = .trace
```
### Hides timezone from log message (saves a few bytes) (`false` by default)
```swift
LGNLogger.hideTimezone = true
```
### Hides label from log message (`false` by default)
```swift
LGNLogger.hideLabel = true
```
### Fetches request ID from Metadata and puts in preamble (`requestID` by default)
```swift
LGNLogger.requestIDKey = "customRequestIDKey"
```