AdHoc fields

AdHoc fields will be applied at the Thirty phase of the life cycle, right after the PreHooks are executed.

Every Log level method can accept AdHoc fields (even custom ones), because all log levels must call Logger.Log() in the end (that accepts AdHoc fields):

func Log(lvl uint64, msg string, adHocFields []LogFields) { ... }

The Logger.Log() receives the AdHoc fields as a slice of LogFields just to ease the forwarding from the log custom levels:

// logLevels.gofunc Trace(msg string, adHocFields ...LogFields) {   l.Log(LvlTrace, msg, adHocFields)}

Example of AdHoc fields usage:

someLogger := logger.New(logger.DefaultConfig()).  Outputs(logger.OutputJsonToWriter(os.Stdout, nil))someLogger.Info("some log", logger.LogFields{  "adHoc-A": "value-A",  "adHoc-B": "value-B",})/*  {    "msg": "some log",    "lvl": 4,    "adHoc-A": "value-A",    "adHoc-B": "value-B"  }*/

AdHoc fields are defined as variadic arguments just to simulate "optional arguments", that don't officially exist in go. Note that if you pass more than one LogFields variadic argument, the latter ones will override the previous ones:

someLogger := logger.New(logger.DefaultConfig()).  Outputs(logger.OutputJsonToWriter(os.Stdout, nil))someLogger.Info("some log",   logger.LogFields{"adHoc-A": "value-A", "adHoc-B": "value-B"},  logger.LogFields{"adHoc-A": "new value"},)/*  {    "msg": "some log",    "lvl": 4,    "adHoc-A": "new value",    "adHoc-B": "value-B"  }*/

AdHoc fields are very suitable to log values that are different for every created log, like the ID of some user, for example:

someLogger := logger.New(logger.DefaultConfig()).  Outputs(logger.OutputJsonToWriter(os.Stdout, nil))someLogger.Info("User created", logger.LogFields{"id": 556})/*  {    "msg": "User created",    "lvl": 4,    "id": 556  }*/