A minimal request framework, built on top of ReactiveSwift. Shirley has full support for URLSession, but is not limited to URLSession, or to the Foundation URL system at all.
Shirley allows a set of value and error transforms to be applied to request results, while using ReactiveSwift SignalProducer values throughout, as a universal language replacing closure callbacks. This allows disparate request-and-callback systems to be unified under a single handling mechanism.
A SessionProtocol value converts Request values into ReactiveSwift SignalProducer values. In addition to Request, Value, and Error associated types, types conforming to SessionProtocol provide producer(for request:).
Sessions can be transformed with the mapRequests(:), mapValues(:), flatMapValues(::), and flatMapErrors(:) functions, or with the built-in transforms for JSON and HTTP support. These transformations return a value of the Session type, which can also be used for type-erasure of SessionProtocol values. For sessions with Hashable requests, the deduplicated property creates a session that ensures only one underlying signal per request is active at any time. Transforming a session is non-destructive, so the underlying session can still be used independently, or transformed into multiple derived sessions.
URLSession is extended to conform to SessionProtocol, using requests of type URLRequest to produce values of type Message<URLResponse, Data> and errors of type NSError.
For example, by default, an URLSession produces pure data - Data. Since transformed sessions use their base sessions to do work, a single base URL session can be used to load JSON data, image data, or file data seamlessly.
The Message type, which implements the MessageProtocol protocol, is a container for response and body values. When used as a SessionProtocol, URLSession produces signal producers that send values of type Message<URLResponse, Data>.
MessageType provides extensions for converting Data bodies to JSON, and for converting URLResponse responses to HTTPURLResponse.
Messages are essentially “nicer two-tuples”, and MessageProtocol provides a tuple property is that format is preferred. The message conversions to tuples, JSON, and HTTP responses are also supported by SessionProtocol, so that sessions producing the prerequisite types can be transformed to sessions producing the derived types.
If necessary, install jazzy:
gem install jazzy
Then run:
make docs
To generate HTML documentation in the Documentation subdirectory.
Add:
github "natestedman/Shirley"
To your Cartfile.
