feat: add event_demo.go.tpl

templates/project/app/events/event_demo.go.tpl

@@ -0,0 +1,71 @@
+package events
+
+import (
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"git.ipao.vip/rogeecn/atom/contracts"
+	"github.com/ThreeDotsLabs/watermill"
+	"github.com/ThreeDotsLabs/watermill/message"
+	"github.com/sirupsen/logrus"
+)
+
+var _ contracts.EventHandler = (*UserRegister)(nil)
+
+type Event struct {
+	ID int `json:"id"`
+}
+
+type ProcessedEvent struct {
+	ProcessedID int       `json:"processed_id"`
+	Time        time.Time `json:"time"`
+}
+
+// @provider(event)
+type UserRegister struct {
+	log *logrus.Entry `inject:"false"`
+}
+
+func (u *UserRegister) Prepare() error {
+	return nil
+}
+
+// Handler implements contracts.EventHandler.
+func (u *UserRegister) Handler(msg *message.Message) ([]*message.Message, error) {
+	consumedPayload := Event{}
+	err := json.Unmarshal(msg.Payload, &consumedPayload)
+	if err != nil {
+		// When a handler returns an error, the default behavior is to send a Nack (negative-acknowledgement).
+		// The message will be processed again.
+		//
+		// You can change the default behaviour by using middlewares, like Retry or PoisonQueue.
+		// You can also implement your own middleware.
+		return nil, err
+	}
+
+	fmt.Printf("received event %+v\n", consumedPayload)
+
+	newPayload, err := json.Marshal(ProcessedEvent{
+		ProcessedID: consumedPayload.ID,
+		Time:        time.Now(),
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	newMessage := message.NewMessage(watermill.NewUUID(), newPayload)
+
+	return nil, nil
+	return []*message.Message{newMessage}, nil
+}
+
+// PublishToTopic implements contracts.EventHandler.
+func (u *UserRegister) PublishToTopic() string {
+	return "event:processed"
+}
+
+// Topic implements contracts.EventHandler.
+func (u *UserRegister) Topic() string {
+	return "event:user-register"
+}