support to remove colors when writing to text files

hooks/writer/writer.go

@@ -10,15 +10,26 @@ import (
 type Hook struct {
 	Writer    io.Writer
 	LogLevels []log.Level
+	Formatter log.Formatter
 }
 
 // Fire will be called when some logging function is called with current hook
 // It will format log entry to string and write it to appropriate writer
 func (hook *Hook) Fire(entry *log.Entry) error {
-	line, err := entry.Bytes()
+
+	var line []byte
+	var err error
+
+	if hook.Formatter != nil {
+		line, err = hook.Formatter.Format(entry)
+	} else {
+		line, err = entry.Bytes()
+	}
+
 	if err != nil {
 		return err
 	}
+
 	_, err = hook.Writer.Write(line)
 	return err
 }

text_formatter.go

@@ -199,37 +199,14 @@ func (f *TextFormatter) Format(entry *Entry) ([]byte, error) {
 	if timestampFormat == "" {
 		timestampFormat = defaultTimestampFormat
 	}
-	if f.isColored() {
-		f.printColored(b, entry, keys, data, timestampFormat)
-	} else {
 
-		for _, key := range fixedKeys {
-			var value interface{}
-			switch {
-			case key == f.FieldMap.resolve(FieldKeyTime):
-				value = entry.Time.Format(timestampFormat)
-			case key == f.FieldMap.resolve(FieldKeyLevel):
-				value = entry.Level.String()
-			case key == f.FieldMap.resolve(FieldKeyMsg):
-				value = entry.Message
-			case key == f.FieldMap.resolve(FieldKeyLogrusError):
-				value = entry.err
-			case key == f.FieldMap.resolve(FieldKeyFunc) && entry.HasCaller():
-				value = funcVal
-			case key == f.FieldMap.resolve(FieldKeyFile) && entry.HasCaller():
-				value = fileVal
-			default:
-				value = data[key]
-			}
-			f.appendKeyValue(b, key, value)
-		}
-	}
+	f.printer(b, entry, keys, data, timestampFormat)
 
 	b.WriteByte('\n')
 	return b.Bytes(), nil
 }
 
-func (f *TextFormatter) printColored(b *bytes.Buffer, entry *Entry, keys []string, data Fields, timestampFormat string) {
+func (f *TextFormatter) printer(b *bytes.Buffer, entry *Entry, keys []string, data Fields, timestampFormat string) {
 	var levelColor int
 	switch entry.Level {
 	case DebugLevel, TraceLevel:
@@ -282,15 +259,27 @@ func (f *TextFormatter) printColored(b *bytes.Buffer, entry *Entry, keys []strin
 
 	switch {
 	case f.DisableTimestamp:
+		if f.DisableColors {
+			fmt.Fprintf(b, "%s%s %-44s ", levelText, caller, entry.Message)
+		} else {
 			fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m%s %-44s ", levelColor, levelText, caller, entry.Message)
+		}
 	case !f.FullTimestamp:
 		fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m[%04d]%s %-44s ", levelColor, levelText, int(entry.Time.Sub(baseTimestamp)/time.Second), caller, entry.Message)
 	default:
+		if f.DisableColors {
+			fmt.Fprintf(b, "%s[%s]%s %-44s ", levelText, entry.Time.Format(timestampFormat), caller, entry.Message)
+		} else {
 			fmt.Fprintf(b, "\x1b[%dm%s\x1b[0m[%s]%s %-44s ", levelColor, levelText, entry.Time.Format(timestampFormat), caller, entry.Message)
 		}
+	}
 	for _, k := range keys {
 		v := data[k]
+		if f.DisableColors {
+			fmt.Fprintf(b, " %s=", k)
+		} else {
 			fmt.Fprintf(b, " \x1b[%dm%s\x1b[0m=", levelColor, k)
+		}
 		f.appendValue(b, v)
 	}
 }