@app.route("/secret")
@fresh_login_required
def secret():
    return render_template("secret.html")

@app.route("/login", methods=["GET", "POST"])
def login():
    <...login-checking code omitted...>
    if user_is_logged_in:
        flash("Logged in!")
        return redirect(request.args.get("next") or url_for("index"))
    else:
        flash("Sorry, but you could not log in.")
        return render_template("login.html")

<form name="loginform" action="{{ url_for('login') }}" method="POST">
Username: <input type="text" name="username" size="30" /><br />
Password: <input type="password" name="password" size="30" /><br />
<input type="submit" value="Login" /><br />

<form name="loginform" action="{{ url_for('login') }}" method="POST">

<form name="loginform" method="POST">

@login_manager.unauthorized_handler
def handle_needs_login():
    flash("You have to be logged in to access this page.")
    return redirect(url_for('account.login', next=request.endpoint))

def redirect_dest(fallback):
    dest = request.args.get('next')
    try:
        dest_url = url_for(dest)
    except:
        return redirect(fallback)
    return redirect(dest_url)

@app.route("/login", methods=["GET", "POST"])
def login():
    ...
    if user_is_logged_in:
        flash("Logged in!")
        return redirect_dest(fallback=url_for('general.index'))
    else:
        flash("Sorry, but you could not log in.")
        return render_template("login.html")

@login_manager.unauthorized_handler
 def handle_needs_login():
     flash("You have to be logged in to access this page.")
     return redirect(url_for('account.login', next=request.path))

def redirect_dest(home):
    dest_url = request.args.get('next')
    if not dest_url:
        dest_url = url_for(home)
    return redirect(dest_url)

@app.route("/login", methods=["GET", "POST"])
def login():
    ...
    if user_is_logged_in:
        flash("Logged in!")
        return redirect_dest(home=anyViewFunctionYouWantToSendUser)
    else:
        flash("Sorry, but you could not log in.")
        return render_template("login.html")