Asynchronous mail sending

[jvsteiner]

It might be nice to be able to configure the default mails that are sent out for email authentication to be able to be sent asynchronously, so the thread is not blocked when signups occur.

[jvsteiner]

I was able to do this myself, as follows:

decorator.py:

from threading import Thread

def async(f):
    def wrapper(*args, **kwargs):
        thr = Thread(target=f, args=args, kwargs=kwargs)
        thr.start()
    return wrapper

and in app.py:

from decorators import async
security = Security(app, user_datastore)

@async
def send_security_email(msg):
    with app.app_context():
       mail.send(msg)

@security.send_mail_task
def async_security_email(msg):
    send_security_email(msg)

Hope this helps someone looking to do the same.

[DukeLeto]

Excellent. Thanks! I actually took a stab at incorporating this yesterday but ran out of time and was having circular import issues. The way you've applied seems to address that. Where did you find @security.send_mail_task declared btw?

[jvsteiner]

I found it referenced here: https://pythonhosted.org/Flask-Security/customizing.html#emails-with-celery and decided to try the pattern mentioned in Miguel Grinberg's blog: http://blog.miguelgrinberg.com/post/the-flask-mega-tutorial-part-xi-email-support

[joshgeller]

Any tips on getting this set up with an application factory function? I'm running into issues with circular imports. Not sure exactly where to drop the decorators. Thanks in advance.

[jvsteiner]

not sure about application factory functions, but I put it in the decorator.py file like shown above. that file doesn't import anything but Thread, which is probably why I didn't get circular imports. I created it for this purpose, though now it has some other odds and ends in it. it's just one more file, and worked great for me.