Authomatic
is an authorization / authentication
client library for Python web applications
inspired by Alex Vagin’s Simpleauth.
In fact, I almost named it Deadsimpleauth,
but that name would be too long
for a succinct library.

- Tweet

# Simple Django Example

In this tutorial we will create a simple Django application that will be able to log users in with Facebook, Twitter and OpenID and retrieve their 5 most recent tweets/statuses.

You can download all the source files we are about to create here.

First create a new Django project named example.

    $ django-admin.py startproject example

Inside the newly created example project create a new application named simple.

    $ cd example
    $ python manage.py startapp simple
    $ cd simple

Open the the `example/simple/urls.py` module and map the `/` root URL to the `home` view and the `/login/[provider_name]` URL to the `login` view. We will create the views later.

    # example/simple/urls.py

    from django.conf.urls import patterns, url

    import views

    urlpatterns = patterns('',
        url(r'^$', views.home, name='home'),
        url(r'^login/(\w*)', views.login, name='login')
    )

We also need to include the `simple` app in the `INSTALLED_APPS` tuple in the `example/example/settings.py` module.

    # example/example/settings.py

    INSTALLED_APPS = (
        'django.contrib.auth',
        'django.contrib.contenttypes',
        'django.contrib.sessions',
        'django.contrib.sites',
        'django.contrib.messages',
        'django.contrib.staticfiles',
        # Uncomment the next line to enable the admin:
        # 'django.contrib.admin',
        # Uncomment the next line to enable admin documentation:
        # 'django.contrib.admindocs',
        'simple',
    )

And create a route to the app in the `example/example/urls.py` module.

    # example/example/urls.py

    from django.conf.urls import patterns, include, url

    urlpatterns = patterns('',
        url(r'^simple/', include('simple.urls')),
    )

Now in the `example/simple` directory create the `config.py` module with the Config dictionary where you set up all the providers you want to use. Yo will need the `consumer_key` and `consumer_secret` which you can get here for Facebook and here for Twitter.

Note

Facebook and other OAuth 2.0 providers require a redirect URI which should be the URL of the login view which we will create in this tutorial and whose walue in our case will be `http://[hostname]/simple/login/fb` for Facebook.

    # config.py

    from authomatic.providers import oauth2, oauth1, openid, gaeopenid

    CONFIG = {

        'tw': { # Your internal provider name

            # Provider class
            'class_': oauth1.Twitter,

            # Twitter is an AuthorizationProvider so we need to set several other properties too:
            'consumer_key': '########################',
            'consumer_secret': '########################',
        },

        'fb': {

            'class_': oauth2.Facebook,

            # Facebook is an AuthorizationProvider too.
            'consumer_key': '########################',
            'consumer_secret': '########################',

            # But it is also an OAuth 2.0 provider and it needs scope.
            'scope': ['user_about_me', 'email', 'publish_stream'],
        },

        'oi': {

            # OpenID provider dependent on the python-openid package.
            'class_': openid.OpenID,
        }
    }

The rest happens in the `example/simple/views.py` file. Open it and import what’s needed.

    # example/simple/views.py

    from django.http import HttpResponse
    from authomatic import Authomatic
    from authomatic.adapters import DjangoAdapter

    from config import CONFIG

Make an instance of the `Authomatic` class and pass the Config together with a random secret string used for session and CSRF token generation to it’s constructor.

    authomatic = Authomatic(CONFIG, 'a super secret random string')

Create the home view with an OpenID form and links to the login view which we are going to create next.

    def home(request):
        return HttpResponse('''
            Login with <a href="login/fb">Facebook</a>.<br />
            Login with <a href="login/tw">Twitter</a>.<br />
            <form action="login/oi">
                <input type="text" name="id" value="me.yahoo.com" />
                <input type="submit" value="Authenticate With OpenID">
            </form>
        ''')

Create the login view which should recieve the `provider_name` URL variable. Inside the view instantiate the `django.http.HttpResponse` class.

    def login(request, provider_name):
        response = HttpResponse()

Now just Log the user in by calling the `Authomatic.login()` method inside the login view. You must pass it the `DjangoAdapter` and the `provider_name` URL variable. The `DjangoAdapter` needs instances of `django.http.HttpRequest` and `django.http.HttpResponse`. The method will redirect the user to the specified provider to prompt him/her for consent and redirect him/her back to this view.

        result = authomatic.login(DjangoAdapter(request, response), provider_name)

The login procedure is over when `Authomatic.login()` returns a `LoginResult`.

Warning

Do not write anything to the response unless the login procedure is over! The `Authomatic.login()` either returns `None`, which means that the login procedure si still pending, or a `LoginResult` which means that the login procedure is over.

        if result:
            response.write('<a href="..">Home</a>')

Hopefully there is no `LoginResult.error` but rather the `LoginResult.user`. Most of the providers don’t provide user info on login. To get more user info we need to call the `User.update()` method.

            if result.error:
                response.write('<h2>Damn that error: {}</h2>'.format(result.error.message))
            elif result.user:
                if not (result.user.name and result.user.id):
                    result.user.update()

Now we can welcome the user by name.

                response.write('<h1>Hi {}</h1>'.format(result.user.name))
                response.write('<h2>Your id is: {}</h2>'.format(result.user.id))
                response.write('<h2>Your email is: {}</h2>'.format(result.user.email))

Seems like we’re done, but we can do more:

If there are `credentials` the user has logged in with an `AuthorizationProvider` i.e. OAuth 1.0a or OAuth 2.0 and we can access his/her protected resources.

                if result.user.credentials:

Each provider has it’s specific API. Let’s first get the user’s five most recent Facebook statuses.

                    if result.provider.name == 'fb':
                        response.write('Your are logged in with Facebook.<br />')

Prepare the Facebook Graph API URL.

                        url = 'https://graph.facebook.com/{}?fields=feed.limit(5)'
                        url = url.format(result.user.id)

Access the protected resource of the user at that URL.

                        access_response = result.provider.access(url)

Parse the response. The `Response.data` is a data structure (list or dictionary) parsed from the `Response.content` which usually is JSON.

                        if access_response.status == 200:
                            # Parse response.
                            statuses = access_response.data.get('feed').get('data')
                            error = access_response.data.get('error')

                            if error:
                                response.write('Damn that error: {}!'.format(error))
                            elif statuses:
                                response.write('Your 5 most recent statuses:<br />')
                                for message in statuses:

                                    text = message.get('message')
                                    date = message.get('created_time')

                                    response.write('<h3>{}</h3>'.format(text))
                                    response.write('Posted on: {}'.format(date))
                        else:
                            response.write('Damn that unknown error!<br />')
                            response.write('Status: {}'.format(response.status))

Do the same with Twitter.

                    if result.provider.name == 'tw':
                        response.write('Your are logged in with Twitter.<br />')

                        # We will get the user's 5 most recent tweets.
                        url = 'https://api.twitter.com/1.1/statuses/user_timeline.json'

                        # You can pass a dictionary of querystring parameters.
                        access_response = result.provider.access(url, {'count': 5})

                        # Parse response.
                        if access_response.status == 200:
                            if type(access_response.data) is list:
                                # Twitter returns the tweets as a JSON list.
                                response.write('Your 5 most recent tweets:')
                                for tweet in access_response.data:
                                    text = tweet.get('text')
                                    date = tweet.get('created_at')

                                    response.write('<h3>{}</h3>'.format(text))
                                    response.write('Tweeted on: {}'.format(date))

                            elif response.data.get('errors'):
                                response.write('Damn that error: {}!'.\
                                                    format(response.data.get('errors')))
                        else:
                            response.write('Damn that unknown error!<br />')
                            response.write('Status: {}'.format(response.status))

Finally return the `response` instance.

        return response

Run the app and navigate to `http://[hostname]/simple` in your browser.

    $ python manage.py runserver

Tip

Most of the providers don’t support authorization from apps running on localhost. Probably the best solution is to use an arbitrary domain as an alias of the `127.0.0.1` IP address.

You can do this on UNIX systems by adding an alias to the `/etc/hosts` file.

        # /etc/hosts
        127.0.0.1    localhost
        127.0.0.1    yourlocalhostalias.com

And here is the complete `example/simple/views.py` module. Remember that you can download all the files we just created from GitHub.

    # example/simple/views.py

    from django.http import HttpResponse
    from authomatic import Authomatic
    from authomatic.adapters import DjangoAdapter

    from config import CONFIG

    authomatic = Authomatic(CONFIG, 'a super secret random string')

    def home(request):
        # Create links and OpenID form to the Login handler.
        return HttpResponse('''
            Login with <a href="login/fb">Facebook</a>.<br />
            Login with <a href="login/tw">Twitter</a>.<br />
            <form action="login/oi">
                <input type="text" name="id" value="me.yahoo.com" />
                <input type="submit" value="Authenticate With OpenID">
            </form>
        ''')

    def login(request, provider_name):
        # We we need the response object for the adapter.
        response = HttpResponse()

        # Start the login procedure.
        result = authomatic.login(DjangoAdapter(request, response), provider_name)

        # If there is no result, the login procedure is still pending.
        # Don't write anything to the response if there is no result!
        if result:
            # If there is result, the login procedure is over and we can write to response.
            response.write('<a href="..">Home</a>')

            if result.error:
                # Login procedure finished with an error.
                response.write('<h2>Damn that error: {}</h2>'.format(result.error.message))

            elif result.user:
                # Hooray, we have the user!

                # OAuth 2.0 and OAuth 1.0a provide only limited user data on login,
                # We need to update the user to get more info.
                if not (result.user.name and result.user.id):
                    result.user.update()

                # Welcome the user.
                response.write('<h1>Hi {}</h1>'.format(result.user.name))
                response.write('<h2>Your id is: {}</h2>'.format(result.user.id))
                response.write('<h2>Your email is: {}</h2>'.format(result.user.email))

                # Seems like we're done, but there's more we can do...

                # If there are credentials (only by AuthorizationProvider),
                # we can _access user's protected resources.
                if result.user.credentials:

                    # Each provider has it's specific API.
                    if result.provider.name == 'fb':
                        response.write('Your are logged in with Facebook.<br />')

                        # We will access the user's 5 most recent statuses.
                        url = 'https://graph.facebook.com/{}?fields=feed.limit(5)'
                        url = url.format(result.user.id)

                        # Access user's protected resource.
                        access_response = result.provider.access(url)

                        if access_response.status == 200:
                            # Parse response.
                            statuses = access_response.data.get('feed').get('data')
                            error = access_response.data.get('error')

                            if error:
                                response.write('Damn that error: {}!'.format(error))
                            elif statuses:
                                response.write('Your 5 most recent statuses:<br />')
                                for message in statuses:

                                    text = message.get('message')
                                    date = message.get('created_time')

                                    response.write('<h3>{}</h3>'.format(text))
                                    response.write('Posted on: {}'.format(date))
                        else:
                            response.write('Damn that unknown error!<br />')
                            response.write('Status: {}'.format(response.status))

                    if result.provider.name == 'tw':
                        response.write('Your are logged in with Twitter.<br />')

                        # We will get the user's 5 most recent tweets.
                        url = 'https://api.twitter.com/1.1/statuses/user_timeline.json'

                        # You can pass a dictionary of querystring parameters.
                        access_response = result.provider.access(url, {'count': 5})

                        # Parse response.
                        if access_response.status == 200:
                            if type(access_response.data) is list:
                                # Twitter returns the tweets as a JSON list.
                                response.write('Your 5 most recent tweets:')
                                for tweet in access_response.data:
                                    text = tweet.get('text')
                                    date = tweet.get('created_at')

                                    response.write('<h3>{}</h3>'.format(text))
                                    response.write('Tweeted on: {}'.format(date))

                            elif response.data.get('errors'):
                                response.write('Damn that error: {}!'.\
                                                    format(response.data.get('errors')))
                        else:
                            response.write('Damn that unknown error!<br />')
                            response.write('Status: {}'.format(response.status))

        return response