snapshot of https://github.com/ThreeDotsLabs/watermill.git (master, 2026-09-15; blobs > 131072B omitted)

_examples/real-world-examples/consumer-groups/api/http.go

@@ -0,0 +1,151 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"strings"
+
+	"github.com/ThreeDotsLabs/watermill"
+	watermillHTTP "github.com/ThreeDotsLabs/watermill-http/pkg/http"
+	"github.com/ThreeDotsLabs/watermill-routing-example/server/common"
+	"github.com/ThreeDotsLabs/watermill/message"
+	"github.com/go-chi/chi/v5"
+)
+
+type Handler struct {
+	storage *storage
+
+	subscriber message.Subscriber
+	publisher  message.Publisher
+	logger     watermill.LoggerAdapter
+
+	lastIDs map[string]int
+}
+
+func (h Handler) Mux() *chi.Mux {
+	r := chi.NewRouter()
+
+	fileServer(r, "/", http.Dir("./public"))
+
+	sseRouter, err := watermillHTTP.NewSSERouter(
+		watermillHTTP.SSERouterConfig{
+			UpstreamSubscriber: h.subscriber,
+		},
+		h.logger,
+	)
+	if err != nil {
+		panic(err)
+	}
+
+	messagesHandler := sseRouter.AddHandler(common.UpdatesTopic, messagesStream{
+		logger:  h.logger,
+		storage: h.storage,
+	})
+
+	r.Route("/api", func(r chi.Router) {
+		r.Use(requestIDMiddleware)
+		r.Get("/messages", messagesHandler)
+		r.Post("/messages/{topic}", h.SendMessage)
+	})
+
+	go func() {
+		err = sseRouter.Run(context.Background())
+		if err != nil {
+			panic(err)
+		}
+	}()
+
+	<-sseRouter.Running()
+
+	return r
+}
+
+func (h Handler) SendMessage(w http.ResponseWriter, r *http.Request) {
+	topic := chi.URLParam(r, "topic")
+
+	h.lastIDs[topic]++
+
+	msgID := fmt.Sprintf("%v", h.lastIDs[topic])
+
+	event := common.UserSignedUp{
+		UserID: watermill.NewUUID(),
+		Consents: common.Consents{
+			Marketing: true,
+			News:      true,
+		},
+	}
+
+	payload, err := json.Marshal(event)
+	if err != nil {
+		logAndWriteError(h.logger, w, err)
+		return
+	}
+
+	msg := message.NewMessage(msgID, payload)
+	msg.Metadata.Set("name", "UserSignedUp")
+
+	err = h.publisher.Publish(topic, msg)
+	if err != nil {
+		logAndWriteError(h.logger, w, err)
+		return
+	}
+
+	w.WriteHeader(204)
+}
+
+type messagesStream struct {
+	storage *storage
+	logger  watermill.LoggerAdapter
+}
+
+func (p messagesStream) GetResponse(w http.ResponseWriter, r *http.Request) (response interface{}, ok bool) {
+	reqID := r.Context().Value("request_id").(string)
+	messages := p.storage.PopAll(reqID)
+	return messages, true
+}
+
+func (p messagesStream) Validate(r *http.Request, msg *message.Message) (ok bool) {
+	var payload common.MessageReceived
+	err := json.Unmarshal(msg.Payload, &payload)
+	if err != nil {
+		return false
+	}
+
+	p.storage.Append(payload)
+
+	return true
+}
+
+func fileServer(r chi.Router, path string, root http.FileSystem) {
+	if strings.ContainsAny(path, "{}*") {
+		panic("FileServer does not permit URL parameters.")
+	}
+
+	fs := http.StripPrefix(path, http.FileServer(root))
+
+	if path != "/" && path[len(path)-1] != '/' {
+		r.Get(path, http.RedirectHandler(path+"/", 301).ServeHTTP)
+		path += "/"
+	}
+	path += "*"
+
+	r.Get(path, func(w http.ResponseWriter, r *http.Request) {
+		fs.ServeHTTP(w, r)
+	})
+}
+
+func logAndWriteError(logger watermill.LoggerAdapter, w http.ResponseWriter, err error) {
+	logger.Error("Error", err, nil)
+	w.WriteHeader(500)
+}
+
+func requestIDMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		ctx := r.Context()
+		requestID := watermill.NewUUID()
+		ctx = context.WithValue(ctx, "request_id", requestID)
+		next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}