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# Logging

Message type notice

On this page all the messages will be just simple `String`, but you may pass any object as the message

As has been said in the setup section, this library contains next levels of logging with their default representations on each platform:

Weight (by order) | LogLevel name | JS | JVM Loggers | Android
--- | --- | --- | --- | ---
0 | TRACE | console.trace + console.debug | Level.FINEST | Log.d
1 | DEBUG | console.debug | Level.FINER | Log.d
2 | VERBOSE | console.info | Level.FINE | Log.v
3 | INFO | console.info | Level.INFO | Log.i
4 | WARNING | console.warn | Level.WARNING | Log.w
5 | ERROR | console.error | Level.SEVERE | Log.e
6 | ASSERT | console.error | Level.SEVERE | Log.wtf

Each of these levels have fullname and shortname shortcat extensions:

- `KSLog.trace`/`KSLog.t`/`KSLog.tS`
- `KSLog.debug`/`KSLog.d`/`KSLog.dS`
- `KSLog.verbose`/`KSLog.v`/`KSLog.vS`
- `KSLog.info`/`KSLog.i`/`KSLog.iS`
- `KSLog.warning`/`KSLog.w`/`KSLog.wS`
- `KSLog.error`/`KSLog.e`/`KSLog.eS`
- `KSLog.assert`/`KSLog.wtf`/`KSLog.wtfS`

And any of these shortcuts may accept one of several arguments combinations:

- Tag (Optional), Throwable (Optional), Message Builder (simple inline callback for lazy creating of log message). This type of arguments is duplicated with `S` suffix for `suspendable` messages creating, for example
- Message, Throwable (Optional)
- Tag, Message, Throwable (Optional)

So, when you want to log some expected exception, there are three common ways to do it:

    val logger = KSLog.default

    // with callback
    logger.info(tag, throwable) {
      "Some your message for this event"
    }

    // with suspendable callback
    logger.infoS(tag, throwable) {
      withContext(Dispatchers.Default) {
        "Some your message for this event"
      }
    }

    // Just with message
    logger.info("Some your message for this event", throwable)

    // With message and tag as strings
    logger.info(tag, "Some your message for this event", throwable)

Of course, any of this calls can be shortenned:

    val logger = KSLog.default

    // with callback
    logger.i(tag, throwable) {
      "Some your message for this event"
    }

    // with suspendable callback
    logger.iS(tag, throwable) {
      withContext(Dispatchers.Default) {
        "Some your message for this event"
      }
    }

    // Just with message
    logger.i("Some your message for this event", throwable)

    // With message and tag as strings
    logger.i(tag, "Some your message for this event", throwable)

There is special shortcat - for base `performLog`. In that case the only change is that you will require to pass the `LogLevel` more obviously:

    val logger = KSLog.default

    // with callback
    logger.log(LogLevel.INFO, tag, throwable) {
      "Some your message for this event"
    }

    // with suspendable callback
    logger.logS(LogLevel.INFO, tag, throwable) {
      withContext(Dispatchers.Default) {
        "Some your message for this event"
      }
    }

    // Just with message
    logger.log(LogLevel.INFO, "Some your message for this event", throwable)

    // With message and tag as strings
    logger.log(LogLevel.INFO, tag, "Some your message for this event", throwable)

OR

    val logger = KSLog.default

    // with callback
    logger.l(LogLevel.INFO, tag, throwable) {
      "Some your message for this event"
    }

    // with suspendable callback
    logger.lS(LogLevel.INFO, tag, throwable) {
      withContext(Dispatchers.Default) {
        "Some your message for this event"
      }
    }

    // Just with message
    logger.l(LogLevel.INFO, "Some your message for this event", throwable)

    // With message and tag as strings
    logger.l(LogLevel.INFO, tag, "Some your message for this event", throwable)