Flask-Potion

Powerful REST API framework for Flask and SQLAlchemy

Project Description

Description

Flask-Potion is a powerful Flask extension for building RESTful JSON APIs. Potion features include validation, model resources and routes, relations, object permissions, filtering, sorting, pagination, signals, and automatic API schema generation.

Potion ships with backends for SQLAlchemy, peewee and MongoEngine models. It is possible to add backends for other data stores, or even to use a subset of Potion without any data store at all.

API client libraries for Python and JavaScript/TypeScript (generic Node as well as AngularJS and Angular) are available.

User’s Guide

The user’s guide and documentation is published here:

http://potion.readthedocs.org/

Versioning

Potion will use semantic versioning from v1.0.0. Until then, the minor version is used for changes known to be breaking.

Features

Powerful API framework both for data-store-linked and plain resources
JSON-based and fully self-documenting with JSON Hyper-Schema
Backend integrations:
- Flask-SQLAlchemy
- Peewee (contributed by Michael Lavers)
- Flask-MongoEngine
Filtering, sorting, pagination, validation, built right in
Smart system for handling relations between resources
Natural keys for extra simple relation querying
Easy-to-use, yet highly flexible, optional permissions system
Signals for pre- and post-processing of requests
Very customizable — everything is just a resource, route, or schema
Access APIs more easily with client libraries for Python and JavaScript/TypeScript

Example (SQLAlchemy)

from flask import Flask
from flask_sqlalchemy import SQLAlchemy
from flask_potion import Api, ModelResource, fields
from flask_potion.routes import ItemRoute

app = Flask(__name__)
db = SQLAlchemy(app)
api = Api(app)

class User(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.String(), nullable=False)

db.create_all()

class UserResource(ModelResource):
    class Meta:
        model = User

    @ItemRoute.GET
    def greeting(self, user) -> fields.String():
        return "Hello, {}!".format(user.name)

api.add_resource(UserResource)

if __name__ == '__main__':
    app.run()

Long-term goals

The web nowadays is increasingly push rather than pull, so Potion is gradually building up to providing a scalable WebSocket service (using asyncio and a message queue). This service will mirror the RESTful API so that every GET request can be done “live”. (In the meantime, you can use the signals module to roll your own solution).

Potion is written in a way that makes it very easy to cache resources. A natural goal is to eventually ship Potion with a built-in server-side caching solution.