feature: add FromContextWithFields, add FromContextWithStd

handler.go

@@ -1,3 +1,4 @@
+//go:build go1.7
 // +build go1.7
 
 package xlog
@@ -44,6 +45,29 @@ func FromContext(ctx context.Context) Logger {
 	return l
 }
 
+// FromContextWithStd gets the logger out of the context.
+// If not logger is stored in the context, a GetLogger is returned.
+func FromContextWithStd(ctx context.Context) Logger {
+	if ctx == nil {
+		return GetLogger()
+	}
+	l, ok := ctx.Value(logKey).(Logger)
+	if !ok {
+		return GetLogger()
+	}
+	return l
+}
+
+// FromContextWithFields gets the logger out of the context.
+// If not logger is stored in the context, a GetLogger is returned.
+func FromContextWithFields(ctx context.Context, fields F) Logger {
+	l := FromContextWithStd(ctx)
+	l = Copy(l)
+	l.SetFields(fields)
+
+	return l
+}
+
 // FromRequest gets the logger in the request's context.
 // This is a shortcut for xlog.FromContext(r.Context())
 func FromRequest(r *http.Request) Logger {

handler_test.go

@@ -1,3 +1,4 @@
+//go:build go1.7
 // +build go1.7
 
 package xlog
@@ -20,6 +21,27 @@ func TestFromContext(t *testing.T) {
 	assert.Equal(t, l, FromContext(ctx))
 }
 
+func TestFromContextWithStd(t *testing.T) {
+	assert.Equal(t, GetLogger(), FromContextWithStd(nil))
+	assert.Equal(t, GetLogger(), FromContextWithStd(context.Background()))
+	l := &logger{}
+	ctx := NewContext(context.Background(), l)
+	assert.Equal(t, l, FromContext(ctx))
+}
+
+func TestFromContextWithFields(t *testing.T) {
+	fields := F{"a": "a"}
+	l := GetLogger()
+	expected := Copy(l)
+	expected.SetFields(fields)
+	assert.Equal(t, expected, FromContextWithFields(nil, fields))
+	assert.Equal(t, expected, FromContextWithFields(context.Background(), fields))
+	nl := &logger{}
+	ctx := NewContext(context.Background(), nl)
+
+	assert.Equal(t, &logger{fields: fields}, FromContextWithFields(ctx, fields))
+}
+
 func TestNewHandler(t *testing.T) {
 	c := Config{
 		Level:  LevelInfo,