RxSwift: ReactiveX for Swift

About Rx

⚠️ This readme describes RxSwift 3.0 version that requires Swift 3.0⚠️

⚠️ If you are looking for Swift 2.3 compatible version, please take a look at RxSwift ~> 2.0 versions and swift-2.3 branch ⚠️

Rx is a generic abstraction of computation expressed through Observable<Element> interface.

This is a Swift version of Rx.

It tries to port as many concepts from the original version as possible, but some concepts were adapted for more pleasant and performant integration with iOS/OSX environment.

Cross platform documentation can be found on ReactiveX.io.

Like the original Rx, its intention is to enable easy composition of asynchronous operations and event/data streams.

KVO observing, async operations and streams are all unified under abstraction of sequence. This is the reason why Rx is so simple, elegant and powerful.

I came here because I want to ...

... understand

• why use rx?
• the basics, getting started with RxSwift
• units - what is Driver, ControlProperty, and Variable ... and why do they exist?
• testing
• tips and common errors
• debugging
• the math behind Rx
• what are hot and cold observable sequences?
• what does the the public API look like?

... install

• Integrate RxSwift/RxCocoa with my app. Installation Guide

... hack around

• with the example app. Running Example App
• with operators in playgrounds. Playgrounds

... interact

• All of this is great, but it would be nice to talk with other people using RxSwift and exchange experiences.
  Join Slack Channel
• Report a problem using the library. Open an Issue With Bug Template
• Request a new feature. Open an Issue With Feature Request Template

... compare

• with other libraries.

... find compatible

• libraries from RxSwiftCommunity.
• Pods using RxSwift.

... see the broader vision

• Does this exist for Android? RxJava
• Where is all of this going, what is the future, what about reactive architectures, how do you design entire apps this way? Cycle.js - this is javascript, but RxJS is javascript version of Rx.

Usage

Here's an example	In Action
Define search for GitHub repositories ...
let searchResults = searchBar.rx.text .throttle(0.3, scheduler: MainScheduler.instance) .distinctUntilChanged() .flatMapLatest { query -> Observable<[Repository]> in if query.isEmpty { return Observable.just([]) } return searchGitHub(query) .catchErrorJustReturn([]) } .observeOn(MainScheduler.instance)</pre></div></td>
... then bind the results to your tableview
searchResults .bindTo(tableView.rx.items(cellIdentifier: "Cell")) { (index, repository: Repository, cell) in cell.textLabel?.text = repository.name cell.detailTextLabel?.text = repository.url } .addDisposableTo(disposeBag)

Requirements

• Xcode 8.0 beta 6 (8S201h)

• Swift 3.0

• iOS 8.0+

• Mac OS X 10.10+

• tvOS 9.0+

• watchOS 2.0+

Installation

Rx doesn't contain any external dependencies.

These are currently the supported options:

Manual

Open Rx.xcworkspace, choose RxExample and hit run. This method will build everything and run the sample app

CocoaPods

# Podfile
use_frameworks!

target 'YOUR_TARGET_NAME' do
    pod 'RxSwift',    '~> 3.0.0.alpha.1'
    pod 'RxCocoa',    '~> 3.0.0.alpha.1'
end

# RxTests and RxBlocking make the most sense in the context of unit/integration tests
target 'YOUR_TESTING_TARGET' do
    pod 'RxBlocking', '~> 3.0.0.alpha.1'
    pod 'RxTests',    '~> 3.0.0.alpha.1'
end

Replace YOUR_TARGET_NAME and then, in the Podfile directory, type:

⚠️ If you want to use CocoaPods with Xcode 8.0 beta and Swift 3.0, you might need to add the following lines to your podfile: ⚠️

post_install do |installer|
  installer.pods_project.targets.each do |target|
    target.build_configurations.each do |config|
      config.build_settings['SWIFT_VERSION'] = '3.0'
      config.build_settings['MACOSX_DEPLOYMENT_TARGET'] = '10.10'
    end
  end
end

$ pod install

Carthage

Add this to Cartfile

github "ReactiveX/RxSwift" "3.0.0.alpha.1"

$ carthage update

Manually using git submodules

• Add RxSwift as a submodule

$ git submodule add git@github.com:ReactiveX/RxSwift.git

• Drag Rx.xcodeproj into Project Navigator
• Go to Project > Targets > Build Phases > Link Binary With Libraries, click + and select RxSwift-[Platform] and RxCocoa-[Platform] targets

References

• http://reactivex.io/
• Reactive Extensions GitHub (GitHub)
• Erik Meijer (Wikipedia)
• Expert to Expert: Brian Beckman and Erik Meijer - Inside the .NET Reactive Framework (Rx) (video)
• Reactive Programming Overview (Jafar Husain from Netflix)
• Subject/Observer is Dual to Iterator (paper)
• Rx standard sequence operators visualized (visualization tool)
• Haskell