Middleware in flask

Question

I just stated using Flask and was trying to implement a small feature in my project. The objective is to set a cookie only if the request comes from a authenticated user.

I found two ways of doing this.

First method

@app.before_request
def before_request():
   # set cookie if user is logged in

Second method, by implementing something like this adding-a-simple-middleware-to-your-flask-application

Can someone explain to me what are the main differences between the two methods and when and where which method should be used.

Also, I am currently using "flask-login" to keep track of the logged in user. If I use the first method, I can easily verify if someone is logged in by importing the current_user

from flask.ext.login import current_user

but if I try to do the same while using the second method, the current_user is always "None" as the application context is incorrect.

So, I wanted to know if I decided to go ahead with the second implementation, how do I check if the user is logged in or not.

Answer 1

I've never used the second method you've mentioned. I'm sure that it can be done with it, but it's very uncommon. I would suggest to use more common features of flask. For sake of maintainers of your code :) So the first method you've mentioned is fine.

Or you can use decorators for more granular access restrictions. Keep in mind that setting cookies in flask can be done when making actual response object. That means you should use Deferred Request Callbacks for setting cookies in decorated function.