log4hs-0.0.6.0: A python logging style log library

Safe HaskellNone
LanguageHaskell2010

Logging.Aeson

Contents

Synopsis

    Aeson Instances

    By using Aeson, we can decode json string into Manager.

    A basic Manager json format:

      {
    "loggers": {"root": {}, "MyLogger": {}},
    "handlers": {"console": {}, "file": {}},
    "formatters": {"default": {}, "simple": {}},
    "disabled": false,
    "catchUncaughtException": true
  }

    In practice, a set of handlers share a formatter, and other handlers share another one, so we define all the formatters in a map, handler refernces the formatter throught its key.

    So as handlers, sinks may share same handlers.

    Examples of Formatter json

      -- a standard format
  {
    "fmt": "%(message)s",
    "datefmt": "%Y-%m-%dT%H:%M:%S"
  }

  -- missing field will use default value
  {
    "fmt": "%(message)s",
    "datefmt": "%Y-%m-%dT%H:%M:%S"
  }

  -- it works as well, just a string
  "%(message)s"

    Examples of Handler json

    Note: Besides some common field, handler's other fields depend on its type.

      -- a standard format
  {
    "type": "StreamHandler",
    "stream": "stderr",
    "level": "DEBUG",
    "filterer": ["Package.Module.Submodule"],
    "formatter": "default",
  }

  -- FileHandler is just a StreamHandler, the stream is created by openFile
  {
    "type": "FileHandler",
    "file": "./default.log",
    "level": "INFO",
    "filterer": [],
    "formatter": "simple",
  }

    Examples of Logger (Sink) json

      -- a standard format
  {
    "level": "DEBUG",
    "filterer": ["Package.Module.Submodule"],
    "handlers": ["console"],
    "propagate": true,
    "disabled": false
  }

  -- this example is equivalent to the first
  {
    "level": "DEBUG",
    "filterer": ["Package.Module.Submodule"],
    "handlers": ["console"]
  }

  -- another example
  {
    "level": "INFO",
    "handlers": ["console", "file"],
    "propagate": false
  }

    Orphan instances