EZ-Facebook Django Utils (for django 1.3+)

FULLY FUNCTIONAL BETA

The purpose of this package is to make facebook integration easy WITHOUT having to make your whole app depend on this package.

This package makes facebook integration easy for all kinds of web sites:

• Web Applications
• Facebook Page Tabs
• Facebook Applications

Included in the suite are:

• Easy to use facebook settings with debug settings
• View decorators that extract information from requests, like signed_request, and facebook graph api.
• NEW: Middleware to apply those decorators to all functions for all defined facebook apps.
• Facebook script template tags
• Facebook Channel URL context variable and view
• Facebook Settings context processors
• Absolute Url template tag, minds current protocol. Useful for posting links and images.
• P3P Cookie middleware to enable the use of cookies in your iframes

Installation

(See ezfacebook/example_settings.py and ezfacebook/example_urls.py for examples, or view below)

Settings :: example settings.py file

TEMPLATE_CONTEXT_PROCESSORS = (
    'ezfacebook.context.context_processors.facebook', # ezfacebook.context: Requirement
)

MIDDLEWARE_CLASSES = (
    'ezfacebook.helpers.middleware.IEIFrameApplicationMiddleware', # ezfacebook.helpers: Optional
    'ezfacebook.user.middleware.FacebookRequestMiddleware', # ezfacebook.user: Optional
)

INSTALLED_APPS = (
    'django.contrib.sites', # ezfacebook.context: Requirement
    'ezfacebook.context', # ezfacebook.context: Optional, allows templatetags absurl
)

# Overrides original FacebookGraphAPI class
FACEBOOK_GRAPH_API_CLASS = 'myproject.myapp.lib.facebook.MyFacebookGraphAPI' # ezfacebook.lib (affects ezfacebook.user), Optional

class FACEBOOK_SETTINGS: # ezfacebook.user, ezfacebook.context: Requirement

    class my_first_fb_app:
        app_id = '00000000000000'
        secret = 'abcdef0123456789'
        scope = 'email,publish_stream,offline_access'

        debug_signed_request = {'id': 23840238402834} # Simulate the JSON returned by a decoded and parsed signed request
        debug_guid = 23840238402834 # Pretend the Facebook user has this Facebook GUID
        debug_token = 'AAAAAAAAAbbbbbbbbbbccccdefffffffffffffffffffetc' # Pretend the Facebook user has this access token

    class my_second_fb_app:
        app_id = '11111111111111'
        secret = '9876543210abcdef'
        scope = ''
        # Disable debugging by omitting the debug settings or by setting them to false

URLS :: example urls.py file

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

urlpatterns = patterns('',
    url(r'^fb/', include('ezfacebook.context.urls')),
)

Packages

Context :: ezfacebook.context, installable app (if necessary)

This packages comes with the following features:

• Template Tags
• Context Processors
• channel.html view

Template Tags :: ezfacebook.context.templatetags

This package must be installed in your application to use template tags.

absurl :: ezfacebook.context.templatetags.absurl

absolute_url :: ezfacebook.context.templatetags.absurl.absolute_url

Builds an absolute URL for the given path. If request is provided, the protocol (http or https) is determined from the request, otherwise http is used.

Example:

{% load absurl %}

{{ obj.image.url|absolute_url }}
{{ obj.image.url|absolute_url:request }}

fb_script :: ezfacebook.context.templatetags.fb_script

These template tags render the HTML required to the Facebook Javascript SDK.

fb_script :: ezfacebook.context.templatetags.fb_script.fb_script

Renders the Facebook Javascript SDK script required for facebook connectivity.

Example:

{% load fb_script %}

{% fb_script 'my_first_fb_app' %}

{% fb_script 'my_first_fb_app' use_share=True %} {# Also loads FB.Share javascript #}

{# See http://bugs.developers.facebook.net/show_bug.cgi?id=19042 #}
{% fb_script 'my_first_fb_app' fix_19042=True %} 

{# See http://bugs.developers.facebook.net/show_bug.cgi?id=20168= #}
{% fb_script 'my_first_fb_app' fix_20168=True %} 

fb_script_with_canvas :: ezfacebook.context.templatetags.fb_script.fb_script_with_canvas

Renders the Facebook Javascript SDK script required for facebook connectivity and sets the Facebook Canvas size.

Example:

{% load fb_script %}

{% fb_script_with_canvas 'my_first_fb_app' canvas_height=2000 canvas_width=500 %} {# 500 is the recommended width for a Page Tab #}

{% fb_script_with_canvas 'my_first_fb_app' canvas_height=2000 canvas_width=500 use_share=True %} {# 500 is the recommended width for a Page Tab #} {# Also loads FB.Share javascript #}

{# See http://bugs.developers.facebook.net/show_bug.cgi?id=19042 #}
{% fb_script_with_canvas 'my_first_fb_app' canvas_height=2000 canvas_width=500 fix_19042=True %} 

{# See http://bugs.developers.facebook.net/show_bug.cgi?id=20168= #}
{% fb_script_with_canvas 'my_first_fb_app' canvas_height=2000 canvas_width=500 fix_20168=True %} 

Helpers :: ezfacebook.helpers

This packages comes with the following features:

• Middleware

Middleware :: ezfacebook.helpers.middleware

This package has middleware to help out your application.

IEIFrameApplicationMiddleware :: ezfacebook.helpers.middleware.IEIFrameApplicationMiddleware

It is not necessary to install this package as an app to use this middleware.

Sets response headers (P3P policy) to allow IE 7-8 to use cookies inside of an iframe. This is useful for websites that are put in iframes on facebook, such as page tabs and facebook apps.

To use it, simply add 'ezfacebook.helpers.middleware.IEIFrameApplicationMiddleware' to MIDDLEWARE_CLASSES in your settings file.

Lib :: ezfacebook.lib

This packages comes with the following features:

• Facebook Graph API
• Library Functions

Adapter :: ezfacebook.lib.adapter

FacebookGraphAPI :: ezfacebook.lib.adapter.FacebookGraphAPI

Wrapper for the "official" GraphAPI object, the difference is that this object is aware of guid & token. Extend this object to add your most frequently used functions, such as posting a link to a wall, vs posting a picture to a wall...

If you extend this class, be sure to set FACEBOOK_GRAPH_API_CLASS in your settings file so that is used by default.

parse_signed_request :: ezfacebook.lib.adapter.parse_signed_request

Parse a signed request based on the secret and return the data (dictionary) Returns None if the signed_request did not parse properly.

Example:

>>> parse_signed_request(request.POST['signed_request'], 'my_secret')
{
 u'user_id': u'1234567890', 
 u'algorithm': u'HMAC-SHA256', 
 u'expires': 1322683200, 
 u'oauth_token': u'AAAAAABbbbcccccddddddeeeeeeeeeeeffffffffgHHHHHhhhhhhhhhhIjlkmop', 
 u'user': {
     u'locale': u'en_US', 
     u'country': u'us', 
     u'age': {u'min': 21}
 }, 
 u'issued_at': 1322676598, 
 u'page': {
     u'admin': False, 
     u'liked': True, 
     u'id': u'46326540287'
 }
}

or 

>>> print parse_signed_request(request.POST['signed_request'], 'my_secret')
None

parse_cookies :: ezfacebook.lib.adapter.parse_cookies

Parse cookies and return the Facebook GUID and Access Token found in the cookie, or None.

Example:

>>> parse_cookies(request.cookies, 'my_app_id', 'my_secret')
('1234567890', 'AAAAAABbbbcccccddddddeeeeeeeeeeeffffffffgHHHHHhhhhhhhhhhIjlkmop')

or 

>>> print parse_cookies(request.cookies, 'my_app_id', 'my_secret')
None

get_graph_from_cookies :: ezfacebook.lib.adapter.get_graph_from_cookies

Returns a FacebookGraphAPI instance or subclass (as specified in the settings), or None, based on cookies.

Example:

>>> get_graph_from_cookies(request.cookies, 'my_app_id', 'my_secret')
<MyFacebookGraphAPI>

or 

>>> print get_graph_from_cookies(request.cookies, 'my_app_id', 'my_secret')
None

User :: ezfacebook.user

This package is responsible for extracting user information from a request. Currently this is done with the use of decorators. In the future, some kind of middleware may be added.

This packages comes with the following features:

• Decorators

Decorators :: ezfacebook.user.decorators

These decorators are used on view functions, they will inject the results as the parameter after request. Any other arguments or keyword arguments are still sent to the view.

parse_signed_request :: ezfacebook.user.decorators.parse_signed_request

Injects a decrypted signed_request into your view function. It can be None. A signed request is good for a lot of things, of which can be found at http://developers.facebook.com/docs/authentication/signed_request/

Example:

from django.conf import settings
from django.core.urlresolvers import reverse
from django.views.generic.simple import direct_to_template

from ezfacebook.context.templatetags import absurl
from ezfacebook.user import decorators

@decorators.parse_signed_request('my_first_fb_app') # or graph_from_cookies(settings.FACEBOOK_SETTINGS.my_first_fb_app)
def index(request, signed_request, *args, **kwargs):
    '''
    >>> print signed_request
    <the debug_signed_request data for 'my_first_fb_app'>
    or
    >>> print signed_request
    None
    or
    >>> print signed_request # Example signed request
    {u'user_id': u'11111111111', u'algorithm': u'HMAC-SHA256', u'expires': 1322683200, u'oauth_token': u'AAAAAAAAAAAAA', 
    u'user': {u'locale': u'en_US', u'country': u'us', u'age': {u'min': 21}}, u'issued_at': 1322676598, 
    u'page': {u'admin': False, u'liked': True, u'id': u'46326540287'}}
    '''

    if signed_request:
        page = signed_request.get('page', None)
        if page:
            liked = page.get('liked', False)
            if liked:
                return direct_to_template(request, 'liked.html')
    return direct_to_template(request, 'unliked.html')

graph_from_cookies :: ezfacebook.user.decorators.graph_from_cookies

Injects a FacebookGraphAPI (or specified subclass) into your view function. It can be None. FacebookGraphAPI is great for making requests to facebook.com, those requests can be found at https://developers.facebook.com/docs/reference/api/

Example:

from django.conf import settings
from django.core.urlresolvers import reverse
from django.views.generic.simple import direct_to_template

from ezfacebook.context.templatetags import absurl
from ezfacebook.user import decorators

@decorators.graph_from_cookies('my_first_fb_app') # or graph_from_cookies(settings.FACEBOOK_SETTINGS.my_first_fb_app)
def post_to_wall(request, graph, *args, **kwargs):

    image_url = absolute_url("%simages/fb_image.png" % settings.MEDIA_URL, request=request)
    link = absolute_url(reverse('myviews.index', request=request))

    graph.put_object("me", "feed", picture=image_url, name='Whatsup', description='Hello', link=link, caption='Pow Mow Local')

    return direct_to_template(request, 'success.html')

Middleware :: ezfacebook.user.middleware

This middleware is used to apply the above decorators to all view functions.

FacebookRequestMiddleware :: ezfacebook.user.middleware.FacebookRequestMiddleware

Put signed_request and graph in the request for each facebook app. Like this: request.ezfb.my_app_name.graph or request.ezfb.my_app_name.signed_request

This cleans up your code so that decorators are not everywhere. However, it does add a little bit of inefficiency when your apps are not always being checked against. Decorators are ugly, but recommended.

Example:

from django.views.generic.simple import direct_to_template 

from myapp import models

def my_view(request):
    """
    An example demonstrating some possibilities of FacebookRequestMiddleware.
    """

    # Get or create a FacebookUser from the graph, if present.

    graph = request.ezfb.my_first_fb_app.graph
    if graph:
        fbuser = models.FacebookUser.objects.get_or_create(facebook_guid=graph.facebook_guid)
    else:
        fbuser = None
    return direct_to_template(request, 'my_first_fb_app/index-liked.html', {'fbuser': fbuser})

    # OR!
    # Show the index page, a different version if they like my_second_fb_app

    signed_request = request.ezfb.my_second_fb_app.signed_request
    if signed_request:
        page_data = signed_request.get('page', None)
        if page_data and page_data.get('liked', False):
            return direct_to_template(request, 'my_second_fb_app/index-liked.html')
    return direct_to_template(request, 'my_second_fb_app/index-unliked.html')