app.py

import os

from db import db
from blacklist import BLACKLIST
from flask import Flask
from flask_restful import Resource, Api
from flask_jwt_extended import JWTManager

from resources.user import UserRegister, User, UserLogin, TokenRefresh, UserLogout
from resources.item import Item, ItemList
from resources.store import Store, StoreList

app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = os.environ.get('DATABASE_URL','sqlite:///data.db')
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['PROPAGATE_EXCEPTIONS'] = True
app.config['JWT_BLACKLIST_ENABLED'] = True  # enable blacklist feature
app.config['JWT_BLACKLIST_TOKEN_CHECKS'] = ['access', 'refresh']  # allow blacklisting for access and refresh tokens
app.secret_key = 'my_super_secret_key'
api = Api(app)

@app.before_first_request
def create_tables():
    db.create_all()

jwt = JWTManager(app)

"""
`claims` are data we choose to attach to each jwt payload
and for each jwt protected endpoint, we can retrieve these claims via `get_jwt_claims()`
one possible use case for claims are access level control, which is shown below.
"""
@jwt.user_claims_loader
def add_claims_to_jwt(identity):  # Remember identity is what we define when creating the access token
    if identity == 1:   # instead of hard-coding, we should read from a config file or database to get a list of admins instead
        return {'is_admin': True}
    return {'is_admin': False}

# This method will check if a token is blacklisted, and will be called automatically when blacklist is enabled
@jwt.token_in_blacklist_loader
def check_if_token_in_blacklist(decrypted_token):
    return decrypted_token['jti'] in BLACKLIST  # Here we blacklist particular users.


# The following callbacks are used for customizing jwt response/error messages.
# The original ones may not be in a very pretty format (opinionated)
@jwt.expired_token_loader
def expired_token_callback():
    return jsonify({
        'description': 'The token has expired.',
        'error': 'token_expired'
    }), 401

@jwt.unauthorized_loader
def missing_token_callback(error):
    return jsonify({
        'description': 'Request does not contain an access token.',
        'error': 'authorization_required'
    }), 401


@jwt.needs_fresh_token_loader
def token_not_fresh_callback():
    return jsonify({
        'description': 'The token is not fresh.',
        'error': 'fresh_token_required'
    }), 401


@jwt.revoked_token_loader
def revoked_token_callback():
    return jsonify({
        'description': 'The token has been revoked.',
        'error': 'token_revoked'
    }), 401

api.add_resource(Store, '/store/<string:name>')
api.add_resource(StoreList, '/stores')
api.add_resource(Item, '/item/<string:name>')
api.add_resource(ItemList, '/items')
api.add_resource(UserRegister, '/register')
api.add_resource(User, '/user/<int:user_id>')
api.add_resource(UserLogin, '/login')
api.add_resource(TokenRefresh, '/refresh')
api.add_resource(UserLogout, '/logout')

if __name__ == '__main__':
    db.init_app(app)
    app.run(port=5000, debug=True)