From 1d1fd2d9ce6cca62f9904035ab7cfa56b76c08ef Mon Sep 17 00:00:00 2001
From: Damien Radtke <damien@buildthis.net>
Date: Tue, 1 Mar 2016 17:33:54 -0600
Subject: [PATCH] Add WriterLevel() function to the logger

This commit adds a variant of the logger's Writer() function that
accepts a log level. When the variant is used, any messages written to
the returned pipe will be written with the provided level. The original
Writer() function uses the logger's Print() method as it always has.
---
 writer.go | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/writer.go b/writer.go
index 1e30b1c75..5768892df 100644
--- a/writer.go
+++ b/writer.go
@@ -7,18 +7,40 @@ import (
 )
 
 func (logger *Logger) Writer() *io.PipeWriter {
+	return logger.WriterLevel(255)
+}
+
+func (logger *Logger) WriterLevel(level Level) *io.PipeWriter {
 	reader, writer := io.Pipe()
 
-	go logger.writerScanner(reader)
+	var printFunc func(args ...interface{})
+	switch level {
+	case DebugLevel:
+		printFunc = logger.Debug
+	case InfoLevel:
+		printFunc = logger.Info
+	case WarnLevel:
+		printFunc = logger.Warn
+	case ErrorLevel:
+		printFunc = logger.Error
+	case FatalLevel:
+		printFunc = logger.Fatal
+	case PanicLevel:
+		printFunc = logger.Panic
+	default:
+		printFunc = logger.Print
+	}
+
+	go logger.writerScanner(reader, printFunc)
 	runtime.SetFinalizer(writer, writerFinalizer)
 
 	return writer
 }
 
-func (logger *Logger) writerScanner(reader *io.PipeReader) {
+func (logger *Logger) writerScanner(reader *io.PipeReader, printFunc func(args ...interface{})) {
 	scanner := bufio.NewScanner(reader)
 	for scanner.Scan() {
-		logger.Print(scanner.Text())
+		printFunc(scanner.Text())
 	}
 	if err := scanner.Err(); err != nil {
 		logger.Errorf("Error while reading from Writer: %s", err)