Logger as interface, fixed #533, fixed #349, fixed #304

Signed-off-by: Vishal Rana <vr@labstack.com>

context.go

@@ -12,7 +12,7 @@ import (
 	"time"
 
 	"github.com/labstack/echo/engine"
-	"github.com/labstack/gommon/log"
+	"github.com/labstack/echo/log"
 
 	"bytes"
 
@@ -162,7 +162,7 @@ type (
 		SetHandler(HandlerFunc)
 
 		// Logger returns the `Logger` instance.
-		Logger() *log.Logger
+		Logger() log.Logger
 
 		// Echo returns the `Echo` instance.
 		Echo() *Echo
@@ -475,7 +475,7 @@ func (c *context) SetHandler(h HandlerFunc) {
 	c.handler = h
 }
 
-func (c *context) Logger() *log.Logger {
+func (c *context) Logger() log.Logger {
 	return c.echo.logger
 }
 

echo.go

@@ -49,7 +49,8 @@ import (
 	"sync"
 
 	"github.com/labstack/echo/engine"
-	"github.com/labstack/gommon/log"
+	"github.com/labstack/echo/log"
+	glog "github.com/labstack/gommon/log"
 )
 
 type (
@@ -65,7 +66,7 @@ type (
 		pool             sync.Pool
 		debug            bool
 		router           *Router
-		logger           *log.Logger
+		logger           log.Logger
 	}
 
 	// Route contains a handler and information for matching against requests.
@@ -225,9 +226,9 @@ func New() (e *Echo) {
 	// Defaults
 	e.SetHTTPErrorHandler(e.DefaultHTTPErrorHandler)
 	e.SetBinder(&binder{})
-	e.logger = log.New("echo")
-	e.logger.SetLevel(log.ERROR)
-
+	l := glog.New("echo")
+	l.SetLevel(glog.ERROR)
+	e.SetLogger(l)
 	return
 }
 
@@ -248,9 +249,14 @@ func (e *Echo) Router() *Router {
 	return e.router
 }
 
-// SetLogPrefix sets the prefix for the logger. Default value is `echo`.
-func (e *Echo) SetLogPrefix(prefix string) {
-	e.logger.SetPrefix(prefix)
+// Logger returns the logger instance.
+func (e *Echo) Logger() log.Logger {
+	return e.logger
+}
+
+// SetLogger defines a custom logger.
+func (e *Echo) SetLogger(l log.Logger) {
+	e.logger = l
 }
 
 // SetLogOutput sets the output destination for the logger. Default value is `os.Std*`
@@ -258,21 +264,11 @@ func (e *Echo) SetLogOutput(w io.Writer) {
 	e.logger.SetOutput(w)
 }
 
-// SetLogLevel sets the log level for the logger. Default value is `log.ERROR`.
+// SetLogLevel sets the log level for the logger. Default value is `glog.ERROR`.
 func (e *Echo) SetLogLevel(l uint8) {
 	e.logger.SetLevel(l)
 }
 
-// SetLogger defines a custom logger.
-func (e *Echo) SetLogger(l *log.Logger) {
-	e.logger = l
-}
-
-// Logger returns the logger instance.
-func (e *Echo) Logger() *log.Logger {
-	return e.logger
-}
-
 // DefaultHTTPErrorHandler invokes the default HTTP error handler.
 func (e *Echo) DefaultHTTPErrorHandler(err error, c Context) {
 	code := http.StatusInternalServerError
@@ -313,7 +309,7 @@ func (e *Echo) SetRenderer(r Renderer) {
 // SetDebug enable/disable debug mode.
 func (e *Echo) SetDebug(on bool) {
 	e.debug = on
-	e.SetLogLevel(log.DEBUG)
+	e.SetLogLevel(glog.DEBUG)
 }
 
 // Debug returns debug mode (enabled or disabled).

engine/engine.go

@@ -7,7 +7,7 @@ import (
 
 	"net"
 
-	"github.com/labstack/gommon/log"
+	"github.com/labstack/echo/log"
 )
 
 type (
@@ -17,7 +17,7 @@ type (
 		SetHandler(Handler)
 
 		// SetLogger sets the logger for the HTTP server.
-		SetLogger(*log.Logger)
+		SetLogger(log.Logger)
 
 		// Start starts the HTTP server.
 		Start() error

log/logger.go

@@ -0,0 +1,23 @@
+package log
+
+import "io"
+
+type (
+	// Logger defines the logging interface.
+	Logger interface {
+		SetOutput(io.Writer)
+		SetLevel(uint8)
+		Print(...interface{})
+		Printf(string, ...interface{})
+		Debug(...interface{})
+		Debugf(string, ...interface{})
+		Info(...interface{})
+		Infof(string, ...interface{})
+		Warn(...interface{})
+		Warnf(string, ...interface{})
+		Error(...interface{})
+		Errorf(string, ...interface{})
+		Fatal(...interface{})
+		Fatalf(string, ...interface{})
+	}
+)