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

_examples/real-world-examples/server-sent-events-htmx/main.go

@@ -0,0 +1,84 @@
+package main
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"math/rand"
+	"time"
+
+	"github.com/kelseyhightower/envconfig"
+	_ "github.com/lib/pq"
+)
+
+type config struct {
+	Port            int    `envconfig:"PORT" required:"true"`
+	DatabaseURL     string `envconfig:"DATABASE_URL" required:"true"`
+	PubSubProjectID string `envconfig:"PUBSUB_PROJECT_ID" required:"true"`
+}
+
+func main() {
+	var cfg config
+	err := envconfig.Process("", &cfg)
+	if err != nil {
+		panic(err)
+	}
+
+	db, err := sql.Open("postgres", cfg.DatabaseURL)
+	if err != nil {
+		panic(err)
+	}
+
+	err = MigrateDB(db)
+	if err != nil {
+		panic(err)
+	}
+
+	repo := NewRepository(db)
+
+	routers, err := NewRouters(cfg, repo)
+	if err != nil {
+		panic(err)
+	}
+
+	go func() {
+		err := routers.EventsRouter.Run(context.Background())
+		if err != nil {
+			panic(err)
+		}
+	}()
+
+	go func() {
+		err := routers.SSERouter.Run(context.Background())
+		if err != nil {
+			panic(err)
+		}
+	}()
+
+	go func() {
+		// This goroutine simulates some events being published in the background
+		ctx := context.Background()
+		for {
+			postID := 1 + rand.Intn(2)
+			if rand.Intn(2) == 0 {
+				_ = routers.EventBus.Publish(ctx, PostViewed{
+					PostID: postID,
+				})
+			} else {
+				_ = routers.EventBus.Publish(ctx, PostReactionAdded{
+					PostID:     postID,
+					ReactionID: allReactions[rand.Intn(len(allReactions))].ID,
+				})
+			}
+
+			time.Sleep(time.Millisecond * time.Duration(3000+rand.Intn(5000)))
+		}
+	}()
+
+	handler := NewHandler(repo, routers.EventBus, routers.SSERouter)
+
+	err = handler.Start(fmt.Sprintf(":%d", cfg.Port))
+	if err != nil {
+		panic(err)
+	}
+}