SAFRS can't split out models definition

README.md

README

Trying to use SAFRS i've structured my App to have separated models, but when i do so I somehow get session ownership issues like the ones described here: https://stackoverflow.com/questions/24291933/sqlalchemy-object-already-attached-to-session

└[cochabamba] python3 server.py                                                      15:12:19
/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/safrs/swagger_doc.py:34: YAMLLoadWarning: calling yaml.load() without Loader=... is deprecated, as the default Loader is unsafe. Please read https://msg.pyyaml.org/load for full details.
yaml_doc = yaml.load(raw_doc)
Starting API: http://0.0.0.0:5000/api
Traceback (most recent call last):
File "server.py", line 17, in <module>
  db.session.add(user)
File "/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/sqlalchemy/orm/scoping.py", line 162, in do
  return getattr(self.registry(), name)(*args, **kwargs)
File "/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 1948, in add
  self._save_or_update_state(state)
File "/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 1961, in _save_or_update_state
  self._save_or_update_impl(state)
File "/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2311, in _save_or_update_impl
  self._update_impl(state)
File "/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2294, in _update_impl
  to_attach = self._before_attach(state, obj)
File "/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2382, in _before_attach
  % (state_str(state), state.session_id, self.hash_key)
sqlalchemy.exc.InvalidRequestError: Object '<User at 0x7f0fa61f3c50>' is already attached to session '1' (this is '2')

app.py

import os
import sys
from flask import Flask
from safrs import SAFRSAPI
from flask import redirect

from database import db

# APP Initialization
#
app = Flask('cerberus server')
app.config.update( SQLALCHEMY_DATABASE_URI = 'sqlite:///test.db',
                   SQLALCHEMY_TRACK_MODIFICATIONS = False,
                   DEBUG = True)

import user
class Models():
    '''Python why you do this to me ?'''
    def __init__(self):
        self.User  = user.User

models = Models()
db.init_app(app)

ROOT_PATH = os.path.dirname(os.path.realpath(__file__))
os.environ.update({'ROOT_PATH': ROOT_PATH})

HOST = sys.argv[1] if len(sys.argv) > 1 else '0.0.0.0'
PORT = 5000
API_PREFIX = '/api/v1'

api = SAFRSAPI(app, port=PORT, host=HOST, prefix=API_PREFIX)


print('Starting API: http://{}:{}/api'.format(HOST,PORT))

@app.route('/')
def goto_api():
    return redirect(API_PREFIX)

@app.teardown_appcontext
def shutdown_session(exception=None):
    '''cfr. http://flask.pocoo.org/docs/0.12/patterns/sqlalchemy/'''
    db.session.remove()

database.py

from flask_sqlalchemy import SQLAlchemy
db = SQLAlchemy()

requirements.txt

Flask
safrs
sqlalchemy

server.py

#!/usr/bin/env python
#
import sys
import os

from app import app, db, models, HOST, PORT

ROOT_PATH = os.path.dirname(os.path.realpath(__file__))
os.environ.update({'ROOT_PATH': ROOT_PATH})
sys.path.append(ROOT_PATH)

# Start the application
with app.app_context():
    db.create_all()

    user = models.User(username='test')
    db.session.add(user)
    db.session.commit()

    for m in models.User.query.all():
        db.session.delete(m)
    db.commit()

    app.run(host=HOST, port = PORT)

user.py

# this goes to /models/user.py
# /models/__init__.py will be something like:
#  import os
#  import glob
#  __all__ = [os.path.basename(f)[:-3]
#             for f in glob.glob(os.path.dirname(__file__) + "/*.py")]

from database import db
from safrs import SAFRSBase
from sqlalchemy import Column, Integer, String

SAFRSBase.db_commit = False

class User(SAFRSBase, db.Model):
    '''
        description: User description
    '''
    __tablename__ = 'Users'

    id = db.Column(String, primary_key=True)
    username = db.Column(db.String(32), index=True)

Safrs autocommits objects when they are instantiated.
This may be circumvented by setting

SAFRSBase.db_commit = False

I Will have to verify this later tho( i m on my phone now)

thanks for pointing that out, with
SAFRSBase.db_commit = False this particular workflow passes, but now i run into the same issues with a model coming from a query.all()

i've updated the gist to show the behaviour:

└[cochabamba] python3 server.py                                                      19:48:48
/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/safrs/swagger_doc.py:34: YAMLLoadWarning: calling yaml.load() without Loader=... is deprecated, as the default Loader is unsafe. Please read https://msg.pyyaml.org/load for full details.
  yaml_doc = yaml.load(raw_doc)
Starting API: http://0.0.0.0:5000/api
Traceback (most recent call last):
  File "server.py", line 21, in <module>
    db.session.delete(m)
  File "/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/sqlalchemy/orm/scoping.py", line 162, in do
    return getattr(self.registry(), name)(*args, **kwargs)
  File "/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 1983, in delete
    self._delete_impl(state, instance, head=True)
  File "/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 1995, in _delete_impl
    to_attach = self._before_attach(state, obj)
  File "/home/xaiki/src/Urissane/cerberus/python/virtualenv/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2382, in _before_attach
    % (state_str(state), state.session_id, self.hash_key)
sqlalchemy.exc.InvalidRequestError: Object '<User at 0x7f9cb3b97450>' is already attached to session '1' (this is '2')

can you try to use db.session.query(User) instead?