The create_api method fails if flask-sqlalchemy has been initialized with init_app()

[TimotheeJeannin]

Let's say I have two files:

server.py

import flask
import flask.ext.sqlalchemy
import flask.ext.restless
from model import db, Person, Computer

app = flask.Flask(__name__)
app.config['DEBUG'] = True
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////tmp/test.db'

with app.app_context():
    db.init_app(app)
    db.drop_all()
    db.create_all()

manager = flask.ext.restless.APIManager(app, flask_sqlalchemy_db=db)
manager.create_api(Person, methods=['GET', 'POST', 'DELETE'])
manager.create_api(Computer, methods=['GET'])

app.run()

model.py

import flask.ext.sqlalchemy

db = flask.ext.sqlalchemy.SQLAlchemy()


class Person(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.Unicode, unique=True)
    birth_date = db.Column(db.Date)


class Computer(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    name = db.Column(db.Unicode, unique=True)
    vendor = db.Column(db.Unicode)
    purchase_time = db.Column(db.DateTime)
    owner_id = db.Column(db.Integer, db.ForeignKey('person.id'))
    owner = db.relationship('Person', backref=db.backref('computers',
                                                         lazy='dynamic'))

When I do a python server.py it works as expected with Flask-Restless version 0.16.0, but fails with Flask-Restless version 0.17.0.

Traceback (most recent call last):
  File "server.py", line 16, in <module>
    manager.create_api(Person, methods=['GET', 'POST', 'DELETE'])
  File "/home/tim/Workspace/testRestless/env/local/lib/python2.7/site-packages/flask_restless/manager.py", line 698, in create_api
    blueprint = self.create_api_blueprint(app=app, *args, **kw)
  File "/home/tim/Workspace/testRestless/env/local/lib/python2.7/site-packages/flask_restless/manager.py", line 566, in create_api_blueprint
    pk_name = primary_key or primary_key_name(model)
  File "/home/tim/Workspace/testRestless/env/local/lib/python2.7/site-packages/flask_restless/helpers.py", line 232, in primary_key_name
    pk_names = primary_key_names(model)
  File "/home/tim/Workspace/testRestless/env/local/lib/python2.7/site-packages/flask_restless/helpers.py", line 214, in primary_key_names
    return [key for key, field in inspect.getmembers(model)
  File "/usr/lib/python2.7/inspect.py", line 253, in getmembers
    value = getattr(object, key)
  File "/home/tim/Workspace/testRestless/env/local/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py", line 454, in __get__
    return type.query_class(mapper, session=self.sa.session())
  File "/home/tim/Workspace/testRestless/env/local/lib/python2.7/site-packages/sqlalchemy/orm/scoping.py", line 71, in __call__
    return self.registry()
  File "/home/tim/Workspace/testRestless/env/local/lib/python2.7/site-packages/sqlalchemy/util/_collections.py", line 878, in __call__
    return self.registry.setdefault(key, self.createfunc())
  File "/home/tim/Workspace/testRestless/env/local/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py", line 704, in create_session
    return SignallingSession(self, **options)
  File "/home/tim/Workspace/testRestless/env/local/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py", line 149, in __init__
    self.app = db.get_app()
  File "/home/tim/Workspace/testRestless/env/local/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py", line 845, in get_app
    raise RuntimeError('application not registered on db '
RuntimeError: application not registered on db instance and no application bound to current context

[pplanel]

Version 0.17.0 confirmed here, downgraded to 0.16.0 and worked.

[diegoponciano]

I've got the same problem with 0.17.0, although I didn't try it with 0.16.0

[nickjbyrne]

Downgrade to 0.16 worked for me

[darrenburns]

Same issue. Seems to work with fine if only using GET for me, as soon as I add POST to the methods it throws this error.

[darrenburns]

In 0.17 you can pass your app as a keyword argument to create_api() and remove it from the constructor of APIManager(). The following should work (although inconvenient):

rest_manager = APIManager(flask_sqlalchemy_db=db)
rest_manager.create_api(SomeModel, methods=['GET', 'POST'], app=app)

Edit: Nevermind, this isn't registering the endpoints for me.

[joergwork]

Same issue.
I tried the following and succeeded but can't explain why:

with app.app_context():
    rest_manager.create_api(SomeModel, methods=['GET', 'POST'])

[jklapuch]

I added next line

db.app = app

before

db.init_app(app)

and restless works.

[green4984]

finally, I found what it happened!

this is below with create_api is ok for me

manager.create_api(Person, methods=['GET', 'POST', 'DELETE'], primary_key='id')

I discover the source code of create_api_blueprint, add a primary_key will not check the db before
app context

[jfinkels]

Hi all,

The init_app and Flask application registration was totally crazy before, since I had no idea what I was doing. It should be fixed now (in the development version). I apologize for that. Closing this now, but please reopen a new issue if you still have problems (since I completely rewrote the code).

[sammarxz]

Check if any route in your app