Flask-Login check if user is authenticated without decorator

Question

From the Flask-Login docs, it's described how a user of the system can require an authenticated User-model to access a method utilising the decorator syntax:

from flask_login import login_required    

@app.route("/settings")
@login_required
def settings():
    pass

Now thats all well and good, but I want to be able to examine if the user is logged in a method, something like this:

@app.route('/main/', methods=['GET', 'POST'])
main_route():
    if request.method == 'GET':
         if user_is_authenticated():    #Do the authentication here
             #load authenticated /main/ html template etc.
             pass
         else:
             #load unauthenticated /main/ html template etc.
             pass
    ...

The reason for this, is because it factorises the GET and POST requests rather than duplicating routes for authenticated users and unauthenticated users.
How can I do this? Is it possible?

Answer 1

This is very simple in flask:

from flask_login import current_user

@app.route(...)
def main_route():
    if current_user.is_authenticated:
         return render_template("main_for_user.html")
    else:
         return render_template("main_for_anonymous.html")

See the documentation on anonymous users.