Flask Framework

Flask reusable applications are tricky (or I’m not capable enough). Here are details on how to enable this application on Flask.

Dependencies

The Flask built-in app depends on sqlalchemy, there’s initial support for MongoEngine ORM too (check below for more details).

Enabling the application

The applications define a Flask Blueprint, which needs to be registered once the Flask app is configured:

from social.apps.flask_app.routes import social_auth

app.register_blueprint(social_auth)

For MongoEngine version:

from social.apps.flask_me_app.routes import social_auth

app.register_blueprint(social_auth)

Models Setup

At the moment the models for python-social-auth are defined inside a function because they need the reference to the current db instance and the User model used on your project (check User model reference below). Once the Flask app and the database are defined, call init_social to register the models:

from social.apps.flask_app.models import init_social

init_social(app, db)

For MongoEngine:

from social.apps.flask_me_app.models import init_social

init_social(app, db)

So far I wasn’t able to find another way to define the models on another way rather than making it as a side-effect of calling this function since the database is not available and current_app cannot be used on init time, just run time.

User model reference

The application keeps a reference to the User model used by your project, define it by using this setting:

SOCIAL_AUTH_USER_MODEL = 'foobar.models.User'

The value must be the import path to the User model.

Global user

The application expects the current logged in user accesible at g.user, define a handler like this to ensure that:

@app.before_request
def global_user():
    g.user = get_current_logged_in_user

Flask-Login

The application works quite well with Flask-Login, ensure to have some similar handlers to these:

@login_manager.user_loader
def load_user(userid):
    try:
        return User.query.get(int(userid))
    except (TypeError, ValueError):
        pass


@app.before_request
def global_user():
    g.user = login.current_user


# Make current user available on templates
@app.context_processor
def inject_user():
    try:
        return {'user': g.user}
    except AttributeError:
        return {'user': None}

Exceptions handling

The Django application has a middleware (that fits in the framework architecture) to facilitate the different exceptions handling raised by python-social-auth. The same can be accomplished (even on a simpler way) in Flask by defining an errorhandler. For example the next code will redirect any social-auth exception to a /socialerror URL:

from social.exceptions import SocialAuthBaseException


@app.errorhandler(500)
def error_handler(error):
    if isinstance(error, SocialAuthBaseException):
        return redirect('/socialerror')

Be sure to set your debug and test flags to False when testing this on your development environment, otherwise the exception will be raised and error handlers won’t be called.

Table Of Contents

Previous topic

Django Framework

Next topic

Pyramid Framework

This Page