URLSession is the API for HTTP connections introduced in iOS 7 and OS X 10.9.
The class URLSession was introduced to Apple's Foundation.framework in iOS 7 and OS X 10.9.
A URLSession object can be considered a group of related data transfer tasks. A response may be received and can be handled via a block statement or delegate methods. URLSession provides status and progress properties, of which support canceling, resuming, or suspending tasks, and resuming suspended, canceled, or failed downloads.
Types of Sessions
URLSession can support three different types of sessions, which is determined by the configuration object used to initialize the session object.
- Default Sessions
- Ephemeral Sessions
- Background Sessions
Types of Tasks
There are three types of tasks, the last two (Download & Upload) of which support background use.
- Data Tasks - Send and receive data via a
NSDataobject - Download Tasks - Retrieves data in the form of a file
- Upload Tasks - Sends data, most typically in the form of a file
Related tags to explore: nsurl nsurlsessiontask
Adapted from Apple's URL Loading System Programming Guide > NSURLSession.
