英文:
Gorilla session.AddFlash Does Not Add Flash Message
问题
我有一个注册页面，其中包含两个处理程序，一个用于显示表单，一个用于处理表单提交。
我试图使用session.AddFlash方法保存错误，然后进行302重定向回注册表单并显示错误。
我设置了一个session存储：
package web
import (
"github.com/gorilla/sessions"
)
var sessionStore = sessions.NewCookieStore([]byte(sessionSecret))
然后我的处理程序如下所示：
package web
import (
"html/template"
"log"
"net/http"
)
func registerForm(w http.ResponseWriter, r *http.Request) {
session, err := sessionStore.Get(r, "mysession")
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
data := map[string]interface{}{}
log.Print("Flashes: ")
log.Print(session.Flashes())
if flashes := session.Flashes(); len(flashes) > 0 {
data["error"] = flashes[0]
}
tmpl, _ := template.ParseFiles("web/templates/register.html.tmpl")
tmpl.Execute(w, data)
}
func register(w http.ResponseWriter, r *http.Request) {
session, err := sessionStore.Get(r, "mysession")
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
r.ParseForm()
username := r.Form["username"][0]
password := r.Form["password"][0]
if UserExists(username) {
log.Print("Username already taken")
session.AddFlash("Username already taken")
http.Redirect(w, r, "/web/register", http.StatusFound)
return
}
_, err = CreateUser(username, password)
log.Print(err)
if err != nil {
session.AddFlash(err.Error())
http.Redirect(w, r, "/web/register", http.StatusFound)
return
}
http.Redirect(w, r, "/web/login", http.StatusFound)
}
通过添加日志，我可以看到UserExists返回true，因此应该添加一个闪存消息，但是在重定向到表单处理程序后，会话中没有保存闪存消息。
英文:
I have a registration page with two handlers, one for displaying the form, one for processing a form submission.
I am trying to use a session.AddFlash method to save an error, then do 302 redirect back to the registration form and display the error.
I set up a session store:
package web
import (
"github.com/gorilla/sessions"
)
var sessionStore = sessions.NewCookieStore([]byte(sessionSecret))
Then my handlers look like this:
package web
import (
"html/template"
"log"
"net/http"
)
func registerForm(w http.ResponseWriter, r *http.Request) {
session, err := sessionStore.Get(r, "mysession")
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
data := map[string]interface{}{}
log.Print("Flashes: ")
log.Print(session.Flashes())
if flashes := session.Flashes(); len(flashes) > 0 {
data["error"] = flashes[0]
}
tmpl, _ := template.ParseFiles("web/templates/register.html.tmpl")
tmpl.Execute(w, data)
}
func register(w http.ResponseWriter, r *http.Request) {
session, err := sessionStore.Get(r, "mysession")
if err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
r.ParseForm()
username := r.Form["username"][0]
password := r.Form["password"][0]
if UserExists(username) {
log.Print("Username already taken")
session.AddFlash("Username already taken")
http.Redirect(w, r, "/web/register", http.StatusFound)
return
}
_, err = CreateUser(username, password)
log.Print(err)
if err != nil {
session.AddFlash(err.Error())
http.Redirect(w, r, "/web/register", http.StatusFound)
return
}
http.Redirect(w, r, "/web/login", http.StatusFound)
}
By adding logs I can see that UserExists returns true therefor a flash message should be added however after redirection to the form handler there is no flash message saved in the session.
答案1
得分: 4
我认为在重定向之前，你需要保存会话。
session.Save(r, w)
http://www.gorillatoolkit.org/pkg/sessions#Session.Save
英文:
I think you have to save the session before you redirect.
session.Save(r, w)
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