add SetLevelOutput - customize writer per level

HISTORY.md

@@ -1,3 +1,7 @@
+## Su 06 September | v0.1.3
+
+Add `SetLevelOutput(levelName string, w io.Writer)` to customize the writer per level.
+
 ## Sa 15 August | v0.1.2
 
 - `Logger.Child` accepts an `interface{}` instead of `string`. This way you can register children for pointers without forcing to naming them. If the key is string or completes the `fmt.Stringer` interface, then it's used as prefix (like always did).

README.md

@@ -37,10 +37,10 @@ Or edit your project's go.mod file and execute $ go build.
 ```bash
 module your_project_name
 
-go 1.14
+go 1.15
 
 require (
-    github.com/kataras/golog v0.1.2
+    github.com/kataras/golog v0.1.3
 )
 ```
 
@@ -250,6 +250,7 @@ func main() {
 ## Examples
 
 * [basic](_examples/basic/main.go)
+* [output per level](_examples/level-output/main.go)
 * [child](_examples/child/main.go)
 * [add new level](_examples/customize-levels/new-level/main.go)
 * [change text and color](_examples/customize-levels/text-and-colors/main.go)

_examples/level-output/main.go

@@ -0,0 +1,49 @@
+// Package main shows how you can register a log output per level.
+package main
+
+import (
+	"os"
+
+	"github.com/kataras/golog"
+)
+
+func simple() {
+	golog.SetLevelOutput("error", os.Stderr)
+
+	golog.Error("an error") // prints to os.Stderr.
+	golog.Info("an info")   // prints to the default output: os.Stdout.
+}
+
+func main() {
+	// use  debug.log and info.log files for the example.
+	debugFile, err := os.OpenFile("debug.log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
+	if err != nil {
+		panic(err)
+	}
+	defer debugFile.Close()
+
+	infoFile, err := os.OpenFile("info.log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
+	if err != nil {
+		panic(err)
+	}
+	defer infoFile.Close()
+	//
+
+	// initialize a new logger
+	logger := golog.New()
+	logger.SetLevel("debug")
+	//
+
+	// set the outputs per log level.
+	logger.SetLevelOutput("debug", debugFile)
+	logger.SetLevelOutput("info", infoFile)
+	//
+
+	// write some logs.
+	logger.Debug("A debug message")
+	// debug.log contains:
+	// [DBUG] 2020/09/06 12:01 A debug message
+	logger.Info("An info message")
+	// info.log contains:
+	// [INFO] 2020/09/06 12:01 An info message
+}

doc.go

@@ -36,7 +36,7 @@ Source code and other details for the project are available at GitHub:
 
 Current Version
 
-0.1.2
+0.1.3
 
 Installation
 
@@ -390,4 +390,4 @@ Examples:
 package golog // import "github.com/kataras/golog"
 
 // Version is the version string representation of the "golog" package.
-const Version = "0.1.2"
+const Version = "0.1.3"

golog.go

@@ -61,6 +61,12 @@ func SetStacktraceLimit(limit int) *Logger {
 	return Default.SetStacktraceLimit(limit)
 }
 
+// SetLevelOutput sets a destination log output for the specific "levelName".
+// For multiple writers use the `io.Multiwriter` wrapper.
+func SetLevelOutput(levelName string, w io.Writer) *Logger {
+	return Default.SetLevelOutput(levelName, w)
+}
+
 // SetLevel accepts a string representation of
 // a `Level` and returns a `Level` value based on that "levelName".
 //

logger.go

@@ -40,9 +40,12 @@ type Logger struct {
 	// Note that this will not override the time and level prefix,
 	// if you want to customize the log message please read the examples
 	// or navigate to: https://github.com/kataras/golog/issues/3#issuecomment-355895870.
-	NewLine  bool
-	mu       sync.Mutex // for logger field changes and printing through pio hijacker.
-	Printer  *pio.Printer
+	NewLine bool
+	mu      sync.Mutex // for logger field changes and printing through pio hijacker.
+	Printer *pio.Printer
+	// The per log level raw writers, optionally.
+	LevelOutput map[Level]io.Writer
+
 	handlers []Handler
 	once     sync.Once
 	logs     sync.Pool
@@ -53,11 +56,12 @@ type Logger struct {
 // and level to `InfoLevel`.
 func New() *Logger {
 	return &Logger{
-		Level:      InfoLevel,
-		TimeFormat: "2006/01/02 15:04",
-		NewLine:    true,
-		Printer:    pio.NewPrinter("", os.Stdout).EnableDirectOutput().Hijack(logHijacker).SetSync(true),
-		children:   newLoggerMap(),
+		Level:       InfoLevel,
+		TimeFormat:  "2006/01/02 15:04",
+		NewLine:     true,
+		Printer:     pio.NewPrinter("", os.Stdout).EnableDirectOutput().Hijack(logHijacker).SetSync(true),
+		LevelOutput: make(map[Level]io.Writer),
+		children:    newLoggerMap(),
 	}
 }
 
@@ -109,7 +113,10 @@ var logHijacker = func(ctx *pio.Ctx) {
 	logger.mu.Lock()
 	defer logger.mu.Unlock()
 
-	w := ctx.Printer
+	w, ok := logger.LevelOutput[l.Level]
+	if !ok {
+		w = ctx.Printer
+	}
 
 	if l.Level != DisableLevel {
 		if level, ok := Levels[l.Level]; ok {
@@ -207,6 +214,13 @@ func (l *Logger) DisableNewLine() *Logger {
 	return l
 }
 
+// SetLevelOutput sets a destination log output for the specific "levelName".
+// For multiple writers use the `io.Multiwriter` wrapper.
+func (l *Logger) SetLevelOutput(levelName string, w io.Writer) *Logger {
+	l.LevelOutput[ParseLevel(levelName)] = w
+	return l
+}
+
 // SetLevel accepts a string representation of
 // a `Level` and returns a `Level` value based on that "levelName".
 //
@@ -484,15 +498,16 @@ func (l *Logger) Scan(r io.Reader) (cancel func()) {
 // This copy is returned as pointer as well.
 func (l *Logger) Clone() *Logger {
 	return &Logger{
-		Prefix:     l.Prefix,
-		Level:      l.Level,
-		TimeFormat: l.TimeFormat,
-		NewLine:    l.NewLine,
-		Printer:    l.Printer,
-		handlers:   l.handlers,
-		children:   newLoggerMap(),
-		mu:         sync.Mutex{},
-		once:       sync.Once{},
+		Prefix:      l.Prefix,
+		Level:       l.Level,
+		TimeFormat:  l.TimeFormat,
+		NewLine:     l.NewLine,
+		Printer:     l.Printer,
+		LevelOutput: l.LevelOutput,
+		handlers:    l.handlers,
+		children:    newLoggerMap(),
+		mu:          sync.Mutex{},
+		once:        sync.Once{},
 	}
 }