frontend: stop refreshing cookies

Signed-off-by: Ahmet Alp Balkan <ahmetb@google.com>

src/frontend/handlers.go

@@ -6,6 +6,7 @@ import (
 	"html/template"
 	"log"
 	"net/http"
+	"time"
 
 	"github.com/google/uuid"
 	"github.com/gorilla/mux"
@@ -17,16 +18,6 @@ var (
 	templates = template.Must(template.ParseGlob("templates/*.html"))
 )
 
-func refreshCookies(next http.HandlerFunc) http.HandlerFunc {
-	return func(w http.ResponseWriter, r *http.Request) {
-		for _, c := range r.Cookies() {
-			c.MaxAge = cookieMaxAge
-			http.SetCookie(w, c)
-		}
-		next(w, r)
-	}
-}
-
 func ensureSessionID(next http.HandlerFunc) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
 		var sessionID string
@@ -58,13 +49,11 @@ func (fe *frontendServer) homeHandler(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
-	log.Printf("currencies: %+v", currencies)
 	products, err := fe.getProducts(r.Context())
 	if err != nil {
 		http.Error(w, err.Error(), http.StatusInternalServerError)
 		return
 	}
-	log.Printf("# products: %d", len(products))
 
 	type productView struct {
 		Item  *pb.Product
@@ -87,6 +76,7 @@ func (fe *frontendServer) homeHandler(w http.ResponseWriter, r *http.Request) {
 		"user_currency": currentCurrency(r),
 		"currencies":    currencies,
 		"products":      ps,
+		"session_id":    r.Context().Value(ctxKeySessionID{}),
 	}); err != nil {
 		log.Println(err)
 	}
@@ -98,7 +88,7 @@ func (fe *frontendServer) productHandler(w http.ResponseWriter, r *http.Request)
 		http.Error(w, "product id not specified", http.StatusBadRequest)
 		return
 	}
-	log.Printf("[productHandler] id=%s", id)
+	log.Printf("[productHandler] id=%s currency=%s", id, currentCurrency(r))
 	p, err := fe.getProduct(r.Context(), id)
 	if err != nil {
 		http.Error(w, fmt.Sprintf("could not retrieve product: %+v", err), http.StatusInternalServerError)
@@ -128,6 +118,7 @@ func (fe *frontendServer) productHandler(w http.ResponseWriter, r *http.Request)
 		"user_currency": currentCurrency(r),
 		"currencies":    currencies,
 		"product":       product,
+		"session_id":    r.Context().Value(ctxKeySessionID{}),
 	}); err != nil {
 		log.Println(err)
 	}
@@ -136,6 +127,7 @@ func (fe *frontendServer) productHandler(w http.ResponseWriter, r *http.Request)
 func (fe *frontendServer) logoutHandler(w http.ResponseWriter, r *http.Request) {
 	log.Printf("[home] session_id=%+v", r.Context().Value(ctxKeySessionID{}))
 	for _, c := range r.Cookies() {
+		c.Expires = time.Now().Add(-time.Hour * 24 * 365)
 		c.MaxAge = -1
 		http.SetCookie(w, c)
 	}
@@ -144,8 +136,8 @@ func (fe *frontendServer) logoutHandler(w http.ResponseWriter, r *http.Request)
 }
 
 func (fe *frontendServer) setCurrencyHandler(w http.ResponseWriter, r *http.Request) {
-	log.Printf("[setCurrency] session_id=%+v", r.Context().Value(ctxKeySessionID{}))
 	cur := r.FormValue("currency_code")
+	log.Printf("[setCurrency] session_id=%+v code=%s", r.Context().Value(ctxKeySessionID{}), cur)
 	if cur != "" {
 		http.SetCookie(w, &http.Cookie{
 			Name:   cookieCurrency,
@@ -153,7 +145,11 @@ func (fe *frontendServer) setCurrencyHandler(w http.ResponseWriter, r *http.Requ
 			MaxAge: cookieMaxAge,
 		})
 	}
-	w.Header().Set("Location", "/")
+	referer := r.Header.Get("referer")
+	if referer == "" {
+		referer = "/"
+	}
+	w.Header().Set("Location", referer)
 	w.WriteHeader(http.StatusFound)
 }
 

src/frontend/main.go

@@ -16,8 +16,9 @@ const (
 	defaultCurrency = "USD"
 	cookieMaxAge    = 60 * 60 * 48
 
-	cookieSessionID = "session-id"
-	cookieCurrency  = "currency"
+	cookiePrefix    = "shop_"
+	cookieSessionID = cookiePrefix + "session-id"
+	cookieCurrency  = cookiePrefix + "currency"
 )
 
 var (
@@ -62,18 +63,11 @@ func main() {
 	}
 
 	r := mux.NewRouter()
-	r.HandleFunc("/", refreshCookies(
-		ensureSessionID(
-			svc.homeHandler))).Methods(http.MethodGet, http.MethodHead)
-	r.HandleFunc("/product/{id}", refreshCookies(
-		ensureSessionID(
-			svc.productHandler))).Methods(http.MethodGet, http.MethodHead)
-	r.PathPrefix("/static/").Handler(http.StripPrefix("/static/",
-		http.FileServer(http.Dir("./static/"))))
+	r.HandleFunc("/", ensureSessionID(svc.homeHandler)).Methods(http.MethodGet, http.MethodHead)
+	r.HandleFunc("/product/{id}", ensureSessionID(svc.productHandler)).Methods(http.MethodGet, http.MethodHead)
+	r.PathPrefix("/static/").Handler(http.StripPrefix("/static/", http.FileServer(http.Dir("./static/"))))
 	r.HandleFunc("/logout", svc.logoutHandler).Methods(http.MethodGet)
-	r.HandleFunc("/setCurrency", refreshCookies(
-		ensureSessionID(
-			svc.setCurrencyHandler))).Methods(http.MethodPost)
+	r.HandleFunc("/setCurrency", ensureSessionID(svc.setCurrencyHandler)).Methods(http.MethodPost)
 	log.Printf("starting server on :" + srvPort)
 	log.Fatal(http.ListenAndServe("localhost:"+srvPort, r))
 }

src/frontend/templates/footer.html

@@ -1,5 +1,7 @@
 {{ define "footer" }}
 <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.1/js/bootstrap.min.js" integrity="sha384-smHYKdLADwkXOn1EmN1qk/HfnUcbVRZyYmZ4qpPea6sjB/pTJ0euyQp0Mk8ck+5T" crossorigin="anonymous"></script>
+
+session-id: {{$.session_id}}
 </body>
 </html>
 {{ end }}

src/frontend/templates/product.html

@@ -3,7 +3,7 @@
 
     <main role="main">
         <div class="py-5">
-            <div class="container bg-light px-lg-5 py-lg-5">
+            <div class="container bg-light py-3 px-lg-5 py-lg-5">
                 <div class="row">
                     <div class="col-12 col-lg-5">
                             <img class="img-fluid" style="width: 100%;"