Customizing order of fields

[William010x]

I want to be able to customize the order of fields, instead of having it sorted alphabetically.

Desired output: `[1] [2] [3] Message

Using PartsOrder to customize the order works, but it displays NIL for logs that don't have that field.

[%!S(<NIL>)] [%!S(<NIL>)] [%!S(<NIL>)] [%!S(<NIL>)] Message

Also, the field gets printed twice.

[1] [2] [3] Message A=[3] B=[2] C=[1]

How would I be able to do this?

If not possible, suggested change:

• Add an attribute FormatWriteFields FieldsFormatter with type func FieldsFormatter (evt map[string]interface{}, buf *bytes.Buffer) that users can pass in (similar to the other formatters)

zerolog/console.go

Line 129 in 263b0bd

w.writeFields(evt, buf)

if w.FormatWriteFields == nil {
    w.writeFields(evt, buf)
} else {
    w.FormatWriteFields(evt, buf)
}

[phuslu]

I think it's hard in zerolog because its console writer unmarshal input to map[string]interface{}.

I re-wrote a zerolog-like logger and a new console writer, the example for your requirement is here https://go.dev/play/p/UmJmLxYXwRO

[wooowlili]

The same request

[adubkov]

[1] [2] [3] Message A=[3] B=[2] C=[1]

This is definitely a bug and should be addressed.

[Alexandre-Stoppini-Cyberdian]

Following here. I found a way to ignore this bug with this :

First, get variables and function colorize from the library :

const (
	colorBlack = iota + 30
	colorRed
	colorGreen
	colorYellow
	colorBlue
	colorMagenta
	colorCyan
	colorWhite

	colorBold     = 1
	colorDarkGray = 90

	unknownLevel = "???"
)

func colorize(s interface{}, c int) string {
	return fmt.Sprintf("\x1b[%dm%v\x1b[0m", c, s)
}

Configure standarOutput

	customStandardOutput:= zerolog.ConsoleWriter{
		Out:                 os.Stdout,
		NoColor:             false,
		TimeFormat:          time.Stamp,
		TimeLocation:        nil,
		PartsOrder:          []string{"level", "time", "application", "function", "message"},
		PartsExclude:        nil,
		FieldsOrder:         nil,
		FieldsExclude:       []string{"application", "function", "message"},
		FormatTimestamp:     nil,
		FormatLevel:         func(i interface{}) string { return strings.ToUpper(fmt.Sprintf("%-6s|", i)) }, // INFO  |
		FormatCaller:        nil,
		FormatMessage:       nil,
		FormatFieldName:     nil,
		FormatFieldValue:    nil,
		FormatErrFieldName:  nil,
		FormatErrFieldValue: nil,
		FormatExtra:         nil,
		FormatPrepare:       nil,
	}

Then, set the logger like

func SetLogger(application, function string) zerolog.Logger {

	return zerolog.New(customStandardOutput).With().Timestamp().
		Str("application", colorize("application=", colorCyan)+application).
		Str("function", colorize("function=", colorCyan)+function).
		Logger()

}

Test this function

func TestInitLogs(t *testing.T) {
	logger := SetLogger("myApp", "TestInitLogs")

	logger.Info().Msg("TestInitLogs")
}

[maxant]

To avoid printing fields twice, configure FieldsExclude and add the fields you don't want printed twice, to that array.

It would be really useful if the function FormatFieldValue were called with the field name as well as the field value, so that you could format depending on which field it is. For example I want to trim the length of the package name, so that the message always starts after 40 columns in the terminal (after 23 for timestamp, 6 for level, a few spacers and 8 for the package name that I set when creating the logger). As a work around, I prepend "pkg:" to the value and then strip that if it is present and then trim/pad to the length 10.