By Liran Zelkha

1. Facebook and
OpenSocial
Development
Liran.zelkha@alunasoft.com

2. Aluna
 Israel’s leading Java/JavaEE and SOA
consulting company
 Customers:

3. How Facebook Apps work
 Every profile page is made up of many
independent portlets or profile boxes.
 Each portlet is generated statically by a possibly
external application and stored by Facebook.
 It could be an iframe, but in most cases is not.
 Portlets are not actually changed in the profile
page – they are changed elsewhere!
 Facebook has mechanisms to link in applications,
and APIs for applications to communicate with
Facebook.

4. Facebook Communication
request for profile
profile
request for canvas
request for canvas content
Facebook API use
update profile box, etc.
canvas
canvas
user facebook.com application (UCT)

5. What can the API do
 Get a list of friend ids or friends who are
running the same app
 Get and set notifications of events
 Set content of profile box
 Get specific information on a user
 Add to the Newsfeed for a user
 Etc.

6. Client Libraries
 Client libraries will simplify the calls to the
platform by reducing the amount of code
you have to write.
 If you don’t use a client library then will
have to do the following for each method
call:
◦ Construct a signature
◦ Create and send a HTTP POST request
◦ Parse the XML result of the request

7. Example Clients
 Facebook Clients
◦ PHP5
◦ Java
 Independent Clients
◦ ActionScript
◦ Cocoa
◦ PHP4
◦ Ruby
◦ Python
◦ VB.NET

8. Methods
 The facebook API currently has 20
methods that can be used to get
information from facebook accounts.

9. Authentication
 facebook.auth.createToken
◦ creates an auth_token to be passed in as a
parameter to login.php
 facebook.auth.getSession
◦ returns the session key bound to an
auth_token

10. Facebook Query Language
 Facebook.fql.query
◦ FQL is a way to query the same facebook data
you can access through the other API
functions, but with a SQL style interface.
◦ SELECT name, affiliations FROM user WHERE
uid IN (SELECT uid2 FROM friend WHERE
uid1=211031) AND "Facebook" IN
affiliations.name AND uid < 10

11. Events
 facebook.events.get
◦ returns all visible events according to the filters
specified
 facebook.events.getMembers
◦ returns membership list data associated with
an event

12. Friends
 facebook.friends.areFriends
◦ returns whether or not each pair of specified
users is friends with each other
 facebook.friends.get
◦ returns the identifiers of the current user’s
Facebook friends
 facebook.friends.getAppUsers
◦ returns the identifiers of the current user’s
Facebook friends who are currently signed in

13. Groups
 facebook.groups.get
◦ returns all visible groups according to the
filters specified
 facebook.groups.getMembers
◦ returns membership list data associated with a
group

14. Notifications
 facebook.notifications.get
◦ returns information on outstanding Facebook
notifications for current session user.
◦ such as messages, friend requests, pokes,
group invites and event invites

15. Photos
 facebook.photos.addTag
◦ adds a tag with the given information to a
photo
 facebook.photos.createAlbum
◦ creates and returns a new album owned by the
current session user
 facebook.photos.get
◦ returns all visible photos according to the filters
specified

16. Photos
 facebook.photos.getAlbums
◦ returns metadata about all of the photo albums
uploaded by the specified user
 facebook.photos.getTags
◦ returns the set of user tags on all photos
specified
 facebook.photos.upload
◦ uploads a photo owned by the current session
user and returns the new photo

17. Users
 facebook.users.getInfo
◦ returns the information in a users profile
 facebook.users.getLoggedInUser
◦ gets the user id associated with the current
session

18. Responses
 Each of these methods can have a
different response format depending on
what you are programming in.
◦ JSON (JavaScript Object Notation)
◦ XML
◦ Facebook PHP Client

19. FBML
 Language used by Facebook to specify
any fragment of Web pages.
 Mostly just like HTML!
 Forms get additional fields added to pass
Facebook parameters silently.
 Images are redirected to local copies.
 Links must be absolute (parameters do
not work as expected in all toolkits).
 Lots of additional Facebook-specific items
◦ <fb:name uid=…> for a user’s name
◦ <fb:profile-pic …> for a user’s profile picture

20. FQL
 Facebook Query Language allows access
to user database with language that is
similar to SQL.
 Example:
◦ SELECT first_name FROM user WHERE
uid=$params->{user}
◦ To get the first name of a user based on the
user-id

21. Creating an Application
 What you need:
◦ Web Server
◦ API toolkit or roll-your-own
 Add the Developer application to your
profile.
 Switch to the Developer application.
 Apply for a key.

26. What does a typical application
do?
 Check CGI parameters.
 Authenticate using Facebook API.
 Draw configuration Web page on canvas.
 Allow user to update options …
 Write FBML to profile box.
 Save per-user state in database or in
filesystem.

27. Example: Profile Box

28. Example: Application Canvas

29. Open Social

30. What problem does it try to solve?
 Writing applications specifically for a
single API

32. Why?
 Developers  Site Owners
◦ Can reuse apps on ◦ New site
new social networks immediately gains
◦ Reduce code many applications
maintenance ◦ Pre-existing broad
◦ Increased potential developer base
audience for
application

33. Who Does It?