Busie Flask Helper

A package to help with common initialization code across Busie Flask projects

Helpful for use with the application factory pattern. Allows for modularization of initialization code, such that factories are not cluttered with boilerplate initialization

Installation

pip install busie-flask-helper

Usage

# in app.py, or wherever application initialization lives
from busie_flask import FlaskHelper
helper = FlaskHelper('abs/path/to/project/')
db = helper.db
auth = helper.auth
cache = helper.cache

# Other Initialization Code omitted

def create_app():
    app = Flask(__name__)
    # Other App Factory initialization omitted

    # this invocation initializes all of the helper objects with the application
    # this includes migration commands, models, views, auth, cache client, orm
    helper.init_app(app, 'relative/path/to/models', '/relative/path/to/views')

    return app

# in some module, maybe an API View
from flask import request
from src.app import auth

class SomeView(MethodView):
    def get(self):
        decoded_token = auth.handle_auth_header(auth_header=request.headers.get('Authorization'))
        # Rest of application api view code

API

FlaskHelper

Public Properties

• db <[SQLAlchemy] (https://flask-sqlalchemy.palletsprojects.com/en/2.x/)>
• auth <[AuthHelper] (#authhelper)>
• cache <[CacheClient] (#cacheclient)>

Public Methods

• FlaskHelper(root_dir, app=None, models_dir=None, views_dir=None)
  • param root_dir: The root directory of the project, best practice to pass an abspath here. if your application lives in src/app then your root dir should be src/
  • See init_app method documentation for specifics on the other params
• init_app(self, app, models_dir, views_dir)
  • param app: A Flask application instance
  • param models_dir: Relative path to the models directory, with respect to the root_dir that the helper was initialized with
  • param views_dir: same as models_dir, but for views

AuthHelper

Public Properties

• JWTPayload <[JWTPaylaod] (#jwtpayload)>: Custom Payload for JWT with validation and defaults
• AuthenticationSignException
• AuthenticationVerificationException

Public Methods

• AuthHelper(app=None): Constructor
• init_app(self, app): Initialize the AuthHelper with a Flask application
  • param app: A Flask application instance. app.config must have AUTH_SECRET

JWTPayload

Public Properties

• sub: REQUIRED The subject of the jwt, should be a string in most cases
• role: REQUIRED The subjects 'role' within the system (i.e superadmin, user, etc.)
• org: REQUIRED The subject's organization
• iat: DEFAULT SUPPLIED POSIX timestamp (seconds) of issue date, defaults to utcnow
• exp: DEFAULT SUPPLIED POSIX timestamp (seconds) of expiration date (defaults to 15 minutes from iat)

Public Methods

• json(self): JSON-ifies the JWT Payload claims.

CacheClient

Public Properties

• redis: The redis instance. Allows for direct interation with the python Redis API

Public Methods

• CacheClient(app=None): Constructor
• init_app(self, app): Initialize the redis client with application.
  • param app: A Flask application instance. app.config must have REDIS_HOST REDIS_PORT and REDIS_DB. NOTE REDIS_PASSWORD is also used, but this method will not throw without it
• get: Alias for redis.get
• set: Alias for redis.set