request.path
is not what you're looking for. It returns the actual path of the URL. So, if your URL is /a/?b=c
, then request.path
returns /a
, not c
as you are expecting.
The next
parameter is after the ?
in the URL, thus it is part of the "query string". Flask has already parsed out items in the query string for you, and you can retrieve these values by using request.args
. If you sent a request to the URL /a/?b=c
and did request.args.get('b')
, you would receive "c"
.
So, you want to use request.args.get('next')
. The documentation shows how this works in an example.
Another thing to keep in mind is that when you are creating your login form in HTML, you don't want to set the "action" attribute. So, don't do this..
<form method="POST" action="/login">
...
</form>
This will cause the POST request to be made to /login
, not /login/?next=%2Fsettings%2F
, meaning your next
parameter will not be part of the query string, and thus you won't be able to retrieve it. You want to leave off the "action" attribute:
<form method="POST">
...
</form>
This will cause the form to be posted to the current URL (which should be /login/?next=%2Fsettings%2f
).