ReactiveJSON

ReactiveJSON is a Swift network framework for JSON services, built using ReactiveCocoa. The framework is minimally designed, yet still highly flexibile.

Features includes:

• Easy-to-create, and highly adatable JSON clients;
• Support for the most common HTTP methods;
• Parameter encoding;
• OAuth2 token support;
• Automatic JSON parsing;

Usage

After a tiny bit of setup, requests look like this:

// Create a `SignalProducer` that will execute the network request when started.
MyJSONService
    .request(endpoint: "foo")
    .startWithResult {
        // `value` is inferred to be `Any`
        print($0.value)
    }
//------------------------------------------------------------------------------
// Bind a GET request to a `MutableProperty`
let users = MutableProperty<[[String:AnyObject]]>([])
users <~ MyJSONService
    .request(endpoint: "users")
    .ignoreError()
//------------------------------------------------------------------------------
// Send a POST request
MyJSONService
    .request(endpoint: "sprocket", method: .Post, parameters: ["foo":"bar"])
    .startWithCompleted {
        print("huzzah!")
    }

Setup

Here is an example of creating a JSON client:

/// A JSON client for the Guild Wars 2 API
struct GW2API: Singleton, ServiceHost {
    // 'Singleton'
    private(set) static var shared = Instance()
    typealias Instance = GW2API

    // 'ServiceHost'
    static var scheme: String { return "https" }
    static var host: String { return "api.guildwars2.com" }
    static var path: String? { return "v2" }
}

Any ServiceHost can make a request. Therefore, a Singleton that is also a ServiceHost can, as well:

// Prints the name of all dyes returned by the "colors" endpoint
GW2API.request(endpoint: "colors", parameters: ["ids":"all"])
    .startWithResult {
        $0.value?.forEach {
            print($0["name"])
        }
    }

Mocking Requests

Benjamin Encz sums up the philosophy behind ReactiveJSON rather well:

"One of my favorite aspects of Swift: Protocols allow you describe truths about types. Generic code can build on top of these truths."

The Singleton protocol requires its Instance alias be a ServiceHost. Without the need to overload any request functions, we can create a client that loads its responses from a fixture file. The result might look something like this:

Note: For a complete example of this concept, see Fixture.swift

class ServiceHostTests: QuickSpec {
    override func spec() {
        describe("resource json") {
            it("handles conformance on assignment") {
                var users: [[String:AnyObject]] = []
                try! Fixture.request(fixture: "users") { users = $0 }

                expect { users.first?["username"] as? String
                    }.toEventually( equal("Bret") )

                expect { users.first?["id"] as? Int
                    }.toEventually( equal(1) )
            }
        }
    }
}