sanic/examples/sanic_peewee.py

## You need the following additional packages for this example
# aiopg
# peewee_async
# peewee


## sanic imports
from sanic import Sanic
from sanic.response import json

## peewee_async related imports
import peewee
from peewee import Model, BaseModel
from peewee_async import Manager, PostgresqlDatabase, execute
from functools import partial
 # we instantiate a custom loop so we can pass it to our db manager

## from peewee_async docs:
# Also there’s no need to connect and re-connect before executing async queries
# with manager! It’s all automatic. But you can run Manager.connect() or
# Manager.close() when you need it.

class AsyncManager(Manager):
    """Inherit the peewee_async manager with our own object
       configuration

       database.allow_sync = False
    """

    def __init__(self, _model_class, *args, **kwargs):
        super(AsyncManager, self).__init__(*args, **kwargs)
        self._model_class = _model_class
        self.database.allow_sync = False

    def _do_fill(self, method, *args, **kwargs):
        _class_method = getattr(super(AsyncManager, self), method)
        pf = partial(_class_method, self._model_class)
        return pf(*args, **kwargs)

    def new(self, *args, **kwargs):
        return self._do_fill('create', *args, **kwargs)

    def get(self, *args, **kwargs):
        return self._do_fill('get', *args, **kwargs)

    def execute(self, query):
        return execute(query)


def _get_meta_db_class(db):
    """creating a declartive class model for db"""
    class _BlockedMeta(BaseModel):
        def __new__(cls, name, bases, attrs):
            _instance = super(_BlockedMeta, cls).__new__(cls, name, bases, attrs)
            _instance.objects = AsyncManager(_instance, db)
            return _instance

    class _Base(Model, metaclass=_BlockedMeta):

        def to_dict(self):
            return self._data

        class Meta:
            database=db
    return _Base


def declarative_base(*args, **kwargs):
    """Returns a new Modeled Class after inheriting meta and Model classes"""
    db = PostgresqlDatabase(*args, **kwargs)
    return _get_meta_db_class(db)


AsyncBaseModel = declarative_base(database='test',
                                  host='127.0.0.1',
                                  user='postgres',
                                  password='mysecretpassword')

# let's create a simple key value store:
class KeyValue(AsyncBaseModel):
    key = peewee.CharField(max_length=40, unique=True)
    text = peewee.TextField(default='')


app = Sanic('peewee_example')


@app.route('/post/<key>/<value>')
async def post(request, key, value):
    """
    Save get parameters to database
    """
    obj = await KeyValue.objects.create(key=key, text=value)
    return json({'object_id': obj.id})


@app.route('/get')
async def get(request):
    """
    Load all objects from database
    """
    all_objects = await KeyValue.objects.execute(KeyValue.select())
    serialized_obj = []
    for obj in all_objects:
        serialized_obj.append({
            'id': obj.id,
            'key': obj.key,
            'value': obj.text}
        )

    return json({'objects': serialized_obj})


if __name__ == "__main__":
    app.run(host='0.0.0.0', port=8000)