Yesterday, Facebook released an updated SDK for the Apple iOS4 , intended for use with Apple's iPad, iPhone, and iPod Touch. Between this and the recently released Facebook SDK for Android, third-party developers can build applications with a social networking component for two of the most popular mobile platforms.
Two key features of the new release are the Graph API and its use of OAuth 2.0 . The Graph API simplifies the way data is read from or written to Facebook. It looks at Facebook's social graph , the network of connections through which Facebook users communicate, and represents each object in the social graph with a unique ID that can be used to fetch such objects, including users, status messages, pages, events, photos, photo albums, groups etc. Relationships between these objects are sorted into connection types. The Graph API replaces the REST API , which used HTTP requests to interact with Facebook.
The Graph API supports introspection of objects, allowing the developer to see all of the connections an object has without having to know their types in advance. The Graph API also allows developers to get detailed analytics about user demographics and how users are sharing the application programmatically. The API supports the Open Graph Protocol , which allows users to add their web pages to Facebook's social graph, regardless of whether or not they are Facebook pages.
The Graph API uses OAuth 2.0 , a simplified version of OAuth, that uses SSL for API communication. It allows the application to obtain an access token from Facebook for a user in order to perform authorized requests on the user's behalf. Facebook Connect is being phased out in favor of OAuth 2.0.
While the most obvious use of the SDK would be for gaming applications, allowing users to compare scores or play against each other, it will also prove useful for news and information applications. One application showcasing the possibilities is FlipBoard , an iPad application that offers up individualized news and assembles it into a magazine format.
Android and iOS-based phones still trail the most popular mobile device OS, RiM's Blackberry, but they're catching up quickly. Android-based Google phones accounted for 27% of new smartphone sales this quarter, and Android phone sales have grown over a whopping 800 percent over sales last year.