Login System Tutorial Part 6 - Logout (Current Progress) ======================================================== `Back to Previous Page`_ .. _Back to Previous Page: https://uadmin-docs.readthedocs.io/en/latest/login_system_views/tutorial/part6.html Structure: * `templates`_ * `home.html`_ * `login.html`_ * `views`_ * `home.go`_ * `login.go`_ * `logout.go`_ * `views_main.go`_ * `main.go`_ templates --------- **home.html** ^^^^^^^^^^^^^^ `Back to Top`_ .. code-block:: html
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{{end}} views ----- **home.go** ^^^^^^^^^^^ `Back to Top`_ .. code-block:: go package views import ( "net/http" "github.com/uadmin/uadmin" ) // HomeHandler handles the home page. func HomeHandler(w http.ResponseWriter, r *http.Request, session *uadmin.Session) { // Initialize the fields that we need in the custom struct. type Context struct { User string OTPRequired bool } // Call the custom struct and assign the full name in the User field under the context object. c := Context{} c.User = session.User.FirstName + " " + session.User.LastName // Check if the user has OTPRequired enabled in the database. if session.User.OTPRequired { /* Assign a boolean value to OTPRequired field. We will use this to manipulate the grammar in the UI. */ c.OTPRequired = true } // Render the home filepath and pass the context data object to the HTML file. uadmin.RenderHTML(w, r, "templates/home.html", c) return } **login.go** ^^^^^^^^^^^^ `Back to Top`_ .. code-block:: go // LoginHandler verifies login data and creating sessions for users. func LoginHandler(w http.ResponseWriter, r *http.Request) { // Initialize the fields that we need in the custom struct. type Context struct { Err string ErrExists bool OTPRequired bool Username string Password string } // Call the Context struct. c := Context{} // If the request method is POST if r.Method == "POST" { // This is a login request from the user. username := r.PostFormValue("username") username = strings.TrimSpace(strings.ToLower(username)) password := r.PostFormValue("password") otp := r.PostFormValue("otp") // Login2FA login using username, password and otp for users with OTPRequired = true. session := uadmin.Login2FA(r, username, password, otp) // Check whether the session returned is nil or the user is not active. if session == nil || !session.User.Active { /* Assign the login validation here that will be used for UI displaying. ErrExists and Err fields are coming from the Context struct. */ c.ErrExists = true c.Err = "Invalid username/password or inactive user" } else { // If the user has OTPRequired enabled, it will print the username and OTP in the terminal. if session.PendingOTP { uadmin.Trail(uadmin.INFO, "User: %s OTP: %s", session.User.Username, session.User.GetOTP()) } /* As long as the username and password is valid, it will create a session cookie in the browser. */ cookie, _ := r.Cookie("session") if cookie == nil { cookie = &http.Cookie{} } cookie.Name = "session" cookie.Value = session.Key cookie.Path = "/" cookie.SameSite = http.SameSiteStrictMode http.SetCookie(w, cookie) // Check for OTP if session.PendingOTP { /* After the user enters a valid username and password in the first part of the form, these values will be used on the second part in the UI where the OTP input field will be displayed afterwards. */ c.Username = username c.Password = password c.OTPRequired = true } else { // If the next value is empty, redirect the page that omits the logout keyword in the last part. if r.URL.Query().Get("next") == "" { http.Redirect(w, r, strings.TrimSuffix(r.RequestURI, "logout"), http.StatusSeeOther) return } // Redirect to the page depending on the value of the next. http.Redirect(w, r, r.URL.Query().Get("next"), http.StatusSeeOther) return } } } // Render the login filepath and pass the context data object to the HTML file. uadmin.RenderHTML(w, r, "templates/login.html", c) } **logout.go** ^^^^^^^^^^^^^ `Back to Top`_ .. code-block:: go package views import ( "net/http" "github.com/uadmin/uadmin" ) // LogoutHandler handles the logout process for the user. func LogoutHandler(w http.ResponseWriter, r *http.Request, session *uadmin.Session) { // Log out the user. uadmin.Logout(r) // Expire all cookies on logout by setting MaxAge to be less than 0. for _, cookie := range r.Cookies() { c := &http.Cookie{ Name: cookie.Name, Value: "", Path: "/", MaxAge: -1, } http.SetCookie(w, c) } http.Redirect(w, r, "/login_system/", http.StatusSeeOther) } **views_main.go** ^^^^^^^^^^^^^^^^^^^ `Back to Top`_ .. code-block:: go package views import ( "net/http" "strings" ) // MainHandler is the main handler for the login system. func MainHandler(w http.ResponseWriter, r *http.Request) { // r.URL.Path creates a new path called "/login_system/" r.URL.Path = strings.TrimPrefix(r.URL.Path, "/login_system") r.URL.Path = strings.TrimSuffix(r.URL.Path, "/") // Authentication : This session is preloaded with a user. session := uadmin.IsAuthenticated(r) if session == nil { // LoginHandler verifies login data and creating sessions for users. LoginHandler(w, r) return } if r.URL.Path == "" { // HomeHandler handles the home page. HomeHandler(w, r, session) return } else if r.URL.Path == "/logout" { /* If the request URL Path is /logout after the /login_system/, it will proceed to this part. e.g. localhost:8080/login_system/logout */ // LogoutHandler handles the logout process for the user. LogoutHandler(w, r, session) return } } main.go ------- `Back to Top`_ .. _Back To Top: https://uadmin-docs.readthedocs.io/en/latest/login_system_views/tutorial/full_code/part6.html#login-system-tutorial-part-6-logout-current-progress .. code-block:: go package main import ( "net/http" // Specify the username that you used inside github.com folder "github.com/username/project_name/views" "github.com/uadmin/uadmin" ) func main() { // Assign RootURL value as "/admin/" and Site Name as "Login System" // NOTE: This code works only if database does not exist yet. uadmin.RootURL = "/admin/" uadmin.SiteName = "Login System" // Login System Main Handler http.HandleFunc("/login_system/", uadmin.Handler(views.MainHandler)) // Run the server uadmin.StartServer() }