logger

README

Logger

ButterflyGate's standard logger

Language

• Japanese
• English

Usage

• simple usage

import (
	"github.com/ButterflyGate/logger"
	"github.com/ButterflyGate/logger/levels"
)

func main(){
	// definition and specify log level
	logger := logger.NewLogger(
		levels.Trace,
	)

	// output message
	logger.Info("hello,world\nhello\nhello")
}

Definition

• use NewLogger.
• Log level must be specified to use this logger at definition.
• log levels are definition in logger/levels directory.

logger := logger.NewLogger(
	levels.Trace,
)

Options

• You can customize the output.
• The function NewLogger can take Optional Arguments controlling output format.

outputOption := logger.DefaultOutputOption().HideCursor().HideLevel().HideTimestamp()
formatOption := logger.DefaultFormatOption().FormatMessageRowLimit(0)
l := logger.NewLogger(
	levels.Trace,
	outputOption, formatOption,
)

Output Option

• OutputOption can control these elements for output or hide
  • log level
  • timestamp
  • called cursor
  • message (change source)
  • struct data (change source)
  • struct name (change source)

option := logger.DefaultOutputOption().HideLevel().HideTimestamp().HideCursor()
l := logger.NewLogger(
	levels.Trace,
	option,
)

Format Option

• FormatOption can control output format
  • using indent or not (json format only)
  • limit message rows count (string type log only)
  • json or text (not implement yet)
  • custom format (not implement yet)

option := logger.DefaultFormatOption().FormatMessageRowLimit(1)
l := logger.NewLogger(
	levels.Trace,
	option,
)

Sample Output

string case

• usage

logger.Info("hello\nworld")

• output

{
  "level": "Trace",
  "timestamp": "2022-10-15T13:35:07.987882308+09:00",
  "cursor": "~/go/src/logger/test/log_test.go:14",
  "message": [
    "hello",
    "world"
  ]
}

structure case

• usage

yourStruct := something.NewYourStruct()
l.Notice(yourStruct)

• output

{
  "level": "Notice",
  "timestamp": "2022-10-15T14:00:16.889360303+09:00",
  "cursor": "/go/src/logger/test/log_test.go:28",
  "structure_data": {
    "ID": 10,
    "FullName": "kyota tahsiro",
    "Birth": "2022-10-15T14:00:15.527879915+09:00"
  },
  "structure_name": "unknown"
}

• it takes second argument for structure_name
• usage

yourStruct := something.NewYourStruct()
l.Notice(yourStruct,"yourStruct")

• output

{
  "level": "Notice",
  "timestamp": "2022-10-15T14:00:16.889360303+09:00",
  "cursor": "/go/src/logger/test/log_test.go:28",
  "structure_data": {
    "ID": 10,
    "FullName": "kyota tahsiro",
    "Birth": "2022-10-15T14:00:15.527879915+09:00"
  },
  "structure_name": "yourStruct"
}

Documentation

Index

• func DefaultFormatOption() formatOption
• func DefaultOutputOption() outputOption
• type Logger
  • func NewLogger[T levels.LogLevelType](level T, options ...option) Logger

Functions

func DefaultFormatOption

func DefaultFormatOption() formatOption

func DefaultOutputOption

func DefaultOutputOption() outputOption

Types

type Logger

type Logger interface {
	ResetLevel(level levels.LogLevel)
	// contains filtered or unexported methods
}

func NewLogger

func NewLogger[T levels.LogLevelType](level T, options ...option) Logger