How to access app.config in a blueprint?

I am trying to access access application configuration inside a blueprint authorisation.py which in a package api. I am initializing the blueprint in __init__.py which is used in authorisation.py.

__init__.py

from flask import Blueprint
api_blueprint = Blueprint("xxx.api", __name__, None)
from api import authorisation

authorisation.py

from flask import request, jsonify, current_app

from ..oauth_adapter import OauthAdapter
from api import api_blueprint as api

client_id = current_app.config.get('CLIENT_ID')
client_secret = current_app.config.get('CLIENT_SECRET')
scope = current_app.config.get('SCOPE')
callback = current_app.config.get('CALLBACK')

auth = OauthAdapter(client_id, client_secret, scope, callback)


@api.route('/authorisation_url')
def authorisation_url():
    url = auth.get_authorisation_url()
    return str(url)

I am getting RuntimeError: working outside of application context

I understand why that is but then what is the correct way of accessing those configuration settings?

----Update---- Temporarily, I have done this.

@api.route('/authorisation_url')
def authorisation_url():
    client_id, client_secret, scope, callback = config_helper.get_config()
    auth = OauthAdapter(client_id, client_secret, scope, callback)
    url = auth.get_authorisation_url()
    return str(url)

Solution 1:

Use flask.current_app in place of app in the blueprint view.

from flask import current_app

@api.route("/info")
def get_account_num():
    num = current_app.config["INFO"]

The current_app proxy is only available in the context of a request.

Solution 2:

Overloading record method seems to be quite easy:

api_blueprint = Blueprint('xxx.api',  __name__, None)
api_blueprint.config = {}

@api_blueprint.record
def record_params(setup_state):
  app = setup_state.app
  api_blueprint.config = dict([(key,value) for (key,value) in app.config.iteritems()])

Solution 3:

To build on tbicr's answer, here's an example overriding the register method example:

from flask import Blueprint

auth = None

class RegisteringExampleBlueprint(Blueprint):
    def register(self, app, options, first_registration=False):
        global auth

        config = app.config
        client_id = config.get('CLIENT_ID')
        client_secret = config.get('CLIENT_SECRET')
        scope = config.get('SCOPE')
        callback = config.get('CALLBACK')

        auth = OauthAdapter(client_id, client_secret, scope, callback)

        super(RegisteringExampleBlueprint,
              self).register(app, options, first_registration)

the_blueprint = RegisteringExampleBlueprint('example', __name__)

And an example using the record decorator:

from flask import Blueprint
from api import api_blueprint as api

auth = None

# Note there's also a record_once decorator
@api.record
def record_auth(setup_state):
    global auth

    config = setup_state.app.config
    client_id = config.get('CLIENT_ID')
    client_secret = config.get('CLIENT_SECRET')
    scope = config.get('SCOPE')
    callback = config.get('CALLBACK')

    auth = OauthAdapter(client_id, client_secret, scope, callback)

Solution 4:

Blueprints have register method which called when you register blueprint. So you can override this method or use record decorator to describe logic which depends from app.