Merge pull request sirupsen#889 from sirupsen/default_field_hook

Add an example hook which adds default fields

example_default_field_value_test.go

@@ -0,0 +1,30 @@
+package logrus_test
+
+import (
+	"github.com/sirupsen/logrus"
+	"os"
+)
+
+type DefaultFieldHook struct {
+	GetValue func() string
+}
+
+func (h *DefaultFieldHook) Levels() []logrus.Level {
+	return logrus.AllLevels
+}
+
+func (h *DefaultFieldHook) Fire(e *logrus.Entry) error {
+	e.Data["aDefaultField"] = h.GetValue()
+	return nil
+}
+
+func ExampleDefaultField() {
+	l := logrus.New()
+	l.Out = os.Stdout
+	l.Formatter = &logrus.TextFormatter{DisableTimestamp: true, DisableColors: true}
+
+	l.AddHook(&DefaultFieldHook{GetValue: func() string { return "with its default value" }})
+	l.Info("first log")
+	// Output:
+	// level=info msg="first log" aDefaultField="with its default value"
+}

example_global_hook_test.go

@@ -21,7 +21,7 @@ func (h *GlobalHook) Fire(e *logrus.Entry) error {
 	return nil
 }
 
-func Example() {
+func ExampleGlobalVariableHook() {
 	l := logrus.New()
 	l.Out = os.Stdout
 	l.Formatter = &logrus.TextFormatter{DisableTimestamp: true, DisableColors: true}