python - How do I run an action for all requests in Flask?

Question

I have some code I want to run for every request that comes into Flask-- specifically adding some analytics information. I know I could do this with a decorator, but I'd rather not waste the extra lines of code for each of my views. Is there a way to just write this code in a catch all that will be applied before or after each view?

Answer 1

Flask has dedicated hooks called before and after requests. Surprisingly, they are called:

• Flask.before_request()
• Flask.after_request()

Both are decorators:

@app.before_request
def do_something_whenever_a_request_comes_in():
    # request is available

@app.after_request
def do_something_whenever_a_request_has_been_handled(response):
    # we have a response to manipulate, always return one
    return response