Alamofire

Alamofire is an HTTP networking library written in Swift. Think of it as AFNetworking, reimagined for the conventions of this new language.

Of course, AFNetworking remains the premiere networking library available for Mac OS X and iOS, and can easily be used in Swift, just like any other Objective-C code. AFNetworking is stable and reliable, and isn't going anywhere. But for anyone looking for something a little more idiomatic to Swift, Alamofire may be right up your alley. (It's not a mutually-exclusive choice, either—AFNetworking & Alamofire will peacefully co-exist within the same codebase.)

Alamofire is named after the Alamo Fire flower, a hybrid variant of the Bluebonnet, the official state flower of Texas.

Features

• Chainable Request / Response methods
• URL / JSON / plist Parameter Encoding
• Upload File / Data / Stream
• Download using Request or Resume data
• Authentication with NSURLCredential
• HTTP Response Validation
• Progress Closure & NSProgress
• cURL Debug Output
• Comprehensive Unit Test Coverage
• Complete Documentation

Requirements

• iOS 7.0+ / Mac OS X 10.9+
• Xcode 6.0

For Xcode 6.1, use the xcode-6.1 branch.

Installation

The infrastructure and best practices for distributing Swift libraries is currently in flux... which is to say, the current installation process kinda sucks.

1. Add Alamofire as a submodule by opening the Terminal, cd-ing into your top-level project directory, and entering the command git submodule add https://github.com/Alamofire/Alamofire.git
2. Open the Alamofire folder, and drag Alamofire.xcodeproj into the file navigator of your Xcode project.
3. In Xcode, navigate to the target configuration window by clicking on the blue project icon, and selecting the application target under the "Targets" heading in the sidebar.
4. In the tab bar at the top of that window, open the "Build Phases" panel.
5. Expand the "Link Binary with Libraries" group, and add Alamofire.framework.
6. Click on the + button at the top left of the panel and select "New Copy Files Phase". Rename this new phase to "Copy Frameworks", set the "Destination" to "Frameworks", and add Alamofire.framework.

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Usage

GET Request

Alamofire.request(.GET, "http://httpbin.org/get")

With Parameters

Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])

With Response Handling

Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])
         .response { (request, response, data, error) in
                     println(request)
                     println(response)
                     println(error)
                   }

With Response String Handling

Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])
         .responseString { (request, response, string, error) in
                  println(string)
         }

HTTP Methods

The Alamofire.Method enum lists the HTTP methods defined in RFC 2616 §9:

public enum Method: String {
    case OPTIONS = "OPTIONS"
    case GET = "GET"
    case HEAD = "HEAD"
    case POST = "POST"
    case PUT = "PUT"
    case PATCH = "PATCH"
    case DELETE = "DELETE"
    case TRACE = "TRACE"
    case CONNECT = "CONNECT"
}

These values can be passed as the first argument of the Alamofire.request method:

Alamofire.request(.POST, "http://httpbin.org/post")

Alamofire.request(.PUT, "http://httpbin.org/put")

Alamofire.request(.DELETE, "http://httpbin.org/delete")

POST Request

let parameters = [
    "foo": "bar",
    "baz": ["a", 1],
    "qux": [
        "x": 1,
        "y": 2,
        "z": 3
    ]
]

Alamofire.request(.POST, "http://httpbin.org/post", parameters: parameters)

This sends the following HTTP Body:

foo=bar&baz[]=a&baz[]=1&qux[x]=1&qux[y]=2&qux[z]=3

Alamofire has built-in support for encoding parameters as URL query / URI form encoded, JSON, and Property List, using the Alamofire.ParameterEncoding enum:

Parameter Encoding

Used to specify the way in which a set of parameters are applied to a URL request.

enum ParameterEncoding {
    case URL
    case JSON
    case PropertyList(format: NSPropertyListFormat,
                      options: NSPropertyListWriteOptions)

    func encode(request: NSURLRequest,
                parameters: [String: AnyObject]?) ->
                    (NSURLRequest, NSError?)
    { ... }
}

• URL: A query string to be set as or appended to any existing URL query for GET, HEAD, and DELETE requests, or set as the body for requests with any other HTTP method. The Content-Type HTTP header field of an encoded request with HTTP body is set to application/x-www-form-urlencoded. Since there is no published specification for how to encode collection types, the convention of appending [] to the key for array values (foo[]=1&foo[]=2), and appending the key surrounded by square brackets for nested dictionary values (foo[bar]=baz).
• JSON: Uses NSJSONSerialization to create a JSON representation of the parameters object, which is set as the body of the request. The Content-Type HTTP header field of an encoded request is set to application/json.
• PropertyList: Uses NSPropertyListSerialization to create a plist representation of the parameters object, according to the associated format and write options values, which is set as the body of the request. The Content-Type HTTP header field of an encoded request is set to application/x-plist.
• Custom: Uses the associated closure value to construct a new request given an existing request and parameters.

Manual Parameter Encoding of an NSURLRequest

let URL = NSURL(string: "http://httpbin.org/get")
var request = NSURLRequest(URL: URL)

let parameters = ["foo": "bar"]
let encoding = Alamofire.ParameterEncoding.URL
(request, _) = encoding.encode(request, parameters)

Response Serialization

Built-in Response Methods

• response()
• responseString(encoding: NSStringEncoding)
• responseJSON(options: NSJSONReadingOptions)
• responsePropertyList(options: NSPropertyListReadOptions)

POST Request with JSON Response

Alamofire.request(.POST, "http://httpbin.org/post", parameters: parameters, encoding: .JSON)
         .responseJSON {(request, response, JSON, error) in
            println(JSON)
         }

Caching

Caching is handled on the system framework level by NSURLCache.

Uploading

Supported Upload Types

• File
• Data
• Stream

Uploading a File

let fileURL = NSBundle.mainBundle()
                      .URLForResource("Default",
                                      withExtension: "png")

Alamofire.upload(.POST, "http://httpbin.org/post", file: fileURL)

Uploading w/Progress

Alamofire.upload(.POST, "http://httpbin.org/post", file: fileURL)
         .progress { (bytesWritten, totalBytesWritten, totalBytesExpectedToWrite) in
             println(totalBytesWritten)
         }
         .responseJSON { (request, response, JSON, error) in
             println(JSON)
         }

Downloading

Supported Download Types

• Request
• Resume Data

Downloading a File

Alamofire.download(.GET, "http://httpbin.org/stream/100", destination: { (temporaryURL, response) in
    if let directoryURL = NSFileManager.defaultManager()
                          .URLsForDirectory(.DocumentDirectory,
                                            inDomains: .UserDomainMask)[0]
                          as? NSURL {
        let pathComponent = response.suggestedFilename

        return directoryURL.URLByAppendingPathComponent(pathComponent!)
    }

    return temporaryURL
})

Using the Default Download Destination

let destination = Alamofire.Request.suggestedDownloadDestination(directory: .DocumentDirectory, domain: .UserDomainMask)

Alamofire.download(.GET, "http://httpbin.org/stream/100", destination: destination)

Downloading a File w/Progress

Alamofire.download(.GET, "http://httpbin.org/stream/100", destination: destination)
         .progress { (bytesRead, totalBytesRead, totalBytesExpectedToRead) in
             println(totalBytesRead)
         }
         .response { (request, response, _, error) in
             println(response)
         }

Authentication

Supported Authentication Schemes

• HTTP Basic
• HTTP Digest
• Kerberos
• NTLM

HTTP Basic Authentication

let user = "user"
let password = "password"

Alamofire.request(.GET, "https://httpbin.org/basic-auth/\(user)/\(password)")
         .authenticate(user: user, password: password)
         .response {(request, response, _, error) in
             println(response)
         }

Authenticating with NSURLCredential

let user = "user"
let password = "password"

let credential = NSURLCredential(user: user, password: password, persistence: .ForSession)

Alamofire.request(.GET, "https://httpbin.org/basic-auth/\(user)/\(password)")
         .authenticate(usingCredential: credential)
         .response {(request, response, _, error) in
             println(response)
         }

Validation

Manual Validation

Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])
         .validate(statusCode: 200..<300)
         .validate(contentType: ["application/json"])
         .response { (_, _, _, error) in
                  println(error)
         }

Automatic Validation

Automatically validates status code within 200...299 range, and that the Content-Type header of the response matches the Accept header of the request, if one is provided.

Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])
         .validate()
         .response { (_, _, _, error) in
                  println(error)
         }

Printable

let request = Alamofire.request(.GET, "http://httpbin.org/ip")

println(request)
// GET http://httpbin.org/ip (200)

DebugPrintable

let request = Alamofire.request(.GET, "http://httpbin.org/get", parameters: ["foo": "bar"])

debugPrintln(request)

Output (cURL)

$ curl -i \
	-H "User-Agent: Alamofire" \
	-H "Accept-Encoding: Accept-Encoding: gzip;q=1.0,compress;q=0.5" \
	-H "Accept-Language: en;q=1.0,fr;q=0.9,de;q=0.8,zh-Hans;q=0.7,zh-Hant;q=0.6,ja;q=0.5" \
	"http://httpbin.org/get?foo=bar"

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Advanced Usage

Alamofire is built on NSURLSession and the Foundation URL Loading System. To make the most of this framework, it is strongly recommended that you are familiar with the concepts and capabilities of the underlying networking stack.

Recommended Reading

• URL Loading System Programming Guide
• NSURLSession Class Reference
• NSURLCache Class Reference
• NSURLAuthenticationChallenge Class Reference

Manager

Top-level convenience methods like Alamofire.request use a shared instance of Alamofire.Manager, which is configured with the default NSURLSessionConfiguration.

As such, the following two statements are equivalent:

Alamofire.request(.GET, "http://httpbin.org/get")

let manager = Alamofire.Manager.sharedInstance
manager.request(NSURLRequest(URL: NSURL(string: "http://httpbin.org/get")))

Applications can create managers for background and ephemeral sessions, as well as new managers that customize properties of the default session configuration, such as default headers (HTTPAdditionalHeaders) or timeout interval (timeoutIntervalForRequest).

Creating a Manager with Default Configuration

let configuration = NSURLSessionConfiguration.defaultSessionConfiguration()
let manager = Alamofire.Manager(configuration: configuration)

Creating a Manager with Background Configuration

let configuration = NSURLSessionConfiguration.backgroundSessionConfiguration("com.example.app")
let manager = Alamofire.Manager(configuration: configuration)

Creating a Manager with Ephemeral Configuration

let configuration = NSURLSessionConfiguration.ephemeralSessionConfiguration()
let manager = Alamofire.Manager(configuration: configuration)

Modifying Session Configuration

var defaultHeaders = Alamofire.Manager.sharedInstance.session.configuration.HTTPAdditionalHeaders ?? [:]
defaultHeaders["DNT"] = "1 (Do Not Track Enabled)"

let configuration = NSURLSessionConfiguration.defaultSessionConfiguration()
configuration.HTTPAdditionalHeaders = defaultHeaders

let manager = Alamofire.Manager(configuration: configuration)

This is not recommended for Authorization or Content-Type headers. Instead, use URLRequestConvertible and ParameterEncoding, respectively.

Request

The result of a request, upload, or download method is an instance of Alamofire.Request. A request is always created using a constructor method from an owning manager, and never initialized directly.

Methods like authenticate, validate, and response return the caller in order to facilitate chaining.

Requests can be suspended, resumed, and cancelled:

• suspend(): Suspends the underlying task and dispatch queue
• resume(): Resumes the underlying task and dispatch queue. If the owning manager does not have startRequestsImmediately set to true, the request must call resume() in order to start.
• cancel(): Cancels the underlying task, producing an error that is passed to any registered response handlers.

URLStringConvertible

Types adopting the URLStringConvertible can be used to construct URL strings, which are then used to construct URL requests. Top-level convenience methods taking a URLStringConvertible argument are provided to allow for type-safe routing behavior.

Applications interacting with web applications in a significant manner are encouraged to adopt either URLStringConvertible or URLRequestConvertible as a way to ensure consistency of requested endpoints.

Type-Safe Routing

enum Router: URLStringConvertible {
    static let baseURLString = "http://example.com"

    case Root
    case User(String)
    case Post(Int, Int, String)

    // MARK: URLStringConvertible

    var URLString: String {
        let path: String = {
            switch self {
            case .Root:
                return "/"
            case .User(let username):
                return "/users/\(username)"
            case .Post(let year, let month, let title):
                let slug = title.stringByReplacingOccurrencesOfString(" ", withString: "-").lowercaseString
                return "/\(year)/\(month)/\(slug)"
            }
        }()

        return Router.baseURLString + path
    }
}

Alamofire.request(.GET, Router.User("mattt"))

URLRequestConvertible

Types adopting the URLRequestConvertible can be used to construct URL requests. Like URLStringConvertible, this is recommended for applications with any significant interactions between client and server.

Top-level and instance methods on Manager taking URLRequestConvertible arguments are provided as a way to provide type-safe routing. Such an approach can be used to abstract away server-side inconsistencies, as well as manage authentication credentials and other state.

API Parameter Abstraction

enum Router: URLRequestConvertible {
    static let baseURLString = "http://example.com"
    static let perPage = 50

    case Search(query: String, page: Int)

    // MARK: URLRequestConvertible

    var URLRequest: NSURLRequest {
        let (path: String, parameters: [String: AnyObject]?) = {
            switch self {
            case .Search(let query, let page) where page > 1:
                return ("/search", ["q": query, "offset": Router.perPage * page])
            case .Search(let query, _):
                return ("/search", ["q": query])
            }
        }()

        let URL = NSURL(string: Router.baseURLString)
        let URLRequest = NSURLRequest(URL: URL.URLByAppendingPathComponent(path))
        let encoding = Alamofire.ParameterEncoding.URL

        return encoding.encode(URLRequest, parameters: parameters).0
    }
}

Alamofire.request(Router.Search(query: "foo bar", page: 1)) // ?q=foo+bar&offset=50

CRUD & Authorization

enum Router: URLRequestConvertible {
    static let baseURLString = "http://example.com"
    static var OAuthToken: String?

    case CreateUser([String: AnyObject])
    case ReadUser(String)
    case UpdateUser(String, [String: AnyObject])
    case DestroyUser(String)

    var method: Alamofire.Method {
        switch self {
        case .CreateUser:
            return .POST
        case .ReadUser:
            return .GET
        case .UpdateUser:
            return .PUT
        case .DestroyUser:
            return .DELETE
        }
    }

    var path: String {
        switch self {
        case .CreateUser:
            return "/users"
        case .ReadUser(let username):
            return "/users/\(username)"
        case .UpdateUser(let username, _):
            return "/users/\(username)"
        case .DestroyUser(let username):
            return "/users/\(username)"
        }
    }

    // MARK: URLRequestConvertible

    var URLRequest: NSURLRequest {
        let URL = NSURL(string: Router.baseURLString)
        let mutableURLRequest = NSMutableURLRequest(URL: URL.URLByAppendingPathComponent(path))
        mutableURLRequest.HTTPMethod = method.toRaw()

        if let token = Router.OAuthToken {
            mutableURLRequest.setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
        }

        switch self {
        case .CreateUser(let parameters):
            return Alamofire.ParameterEncoding.JSON.encode(mutableURLRequest, parameters: parameters).0
        case .UpdateUser(_, let parameters):
            return Alamofire.ParameterEncoding.URL.encode(mutableURLRequest, parameters: parameters).0
        default:
            return mutableURLRequest
        }
    }
}

Alamofire.request(Router.ReadUser("mattt")) // GET /users/mattt

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Contact

Follow AFNetworking on Twitter (@AFNetworking)

Creator

• Mattt Thompson (@mattt)

License

Alamofire is released under an MIT license. See LICENSE for more information.