My goal is to get arbitrary code to run after my Flask application is started. Here is what I've got:
def run():
from webapp import app
app.run(debug=True, use_reloader=False)
Ideally I would be able to just do this:
def run():
from webapp import app
app.run(debug=True, use_reloader=False)
some_code()
But the code doesn't continue past app.run(), so some_code() never runs.
The solution I'm working on at the moment is to run some_code() in a separate thread from app.run(), create a before first request function that sets this:
app.is_running = True
Then get some_code() to shoot a basic request to app so that the 'before first request' code runs. This is fairly convoluted and going to be hard to document. I would rather use app.is_running parameter which already is provided in Flask, or use a @app.after_server_start decorator, but to my knowledge neither of those exists.
Help me make this code better?
Posthumous: Every time I think about this issue, it makes me wish that a @app.after_server_start decorator existed.
If you need to execute some code after your flask application is started but strictly before the first request, not even be triggered by the execution of the first request as @app.before_first_request can handle, you should use Flask_Script, as CESCO said, but you could subclass the class Server and overwrite the __ call __ method, instead of overwriting the runserver command with @manager.command:
from flask import Flask
from flask_script import Manager, Server
def custom_call():
#Your code
pass
class CustomServer(Server):
def __call__(self, app, *args, **kwargs):
custom_call()
#Hint: Here you could manipulate app
return Server.__call__(self, app, *args, **kwargs)
app = Flask(__name__)
manager = Manager(app)
# Remeber to add the command to your Manager instance
manager.add_command('runserver', CustomServer())
if __name__ == "__main__":
manager.run()
This way you don't override default options of runserver command.