RxSwift: ReactiveX for Swift

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/macOS 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
traits - what are Single, Completable, Maybe, Driver, and ControlProperty ... and why do they exist?
testing
tips and common errors
debugging
the math behind Rx
what are hot and cold observable sequences?

... 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
Help out Check out contribution guide

... compare

with other libraries.

... understand the structure

RxSwift comprises five separate components depending on eachother in the following way:

┌──────────────┐    ┌──────────────┐
│   RxCocoa    ├────▶   RxRelay    │
└───────┬──────┘    └──────┬───────┘
        │                  │        
┌───────▼──────────────────▼───────┐
│             RxSwift              │
└───────▲──────────────────▲───────┘
        │                  │        
┌───────┴──────┐    ┌──────┴───────┐
│    RxTest    │    │  RxBlocking  │
└──────────────┘    └──────────────┘

RxSwift: The core of RxSwift, providing the Rx standard as (mostly) defined by ReactiveX. It has no other dependencies.
RxCocoa: Provides Cocoa-specific capabilities for general iOS/macOS/watchOS & tvOS app development, such as Binders, Traits, and much more. It depends on both RxSwift and RxRelay.
RxRelay: Provides PublishRelay and BehaviorRelay, two simple wrappers around Subjects. It depends on RxSwift.
RxTest and RxBlocking: Provides testing capabilities for Rx-based systems. It depends on RxSwift.

... 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.orEmpty .throttle(.milliseconds(300), scheduler: MainScheduler.instance) .distinctUntilChanged() .flatMapLatest { query -> Observable<[Repository]> in if query.isEmpty { return .just([]) } return searchGitHub(query) .catchErrorJustReturn([]) } .observeOn(MainScheduler.instance)
... then bind the results to your tableview
searchResults .bind(to: tableView.rx.items(cellIdentifier: "Cell")) { (index, repository: Repository, cell) in cell.textLabel?.text = repository.name cell.detailTextLabel?.text = repository.url } .disposed(by: disposeBag)

Requirements

Xcode 10.2
Swift 5.0

For Xcode 10.1 and below, use RxSwift 4.5.

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', '~> 5'
    pod 'RxCocoa', '~> 5'
end

# RxTest and RxBlocking make the most sense in the context of unit/integration tests
target 'YOUR_TESTING_TARGET' do
    pod 'RxBlocking', '~> 5'
    pod 'RxTest', '~> 5'
end

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

$ pod install

Carthage

Officially supported: Carthage 0.33 and up.

Add this to Cartfile

github "ReactiveX/RxSwift" ~> 5.0

$ carthage update

Carthage as a Static Library

Carthage defaults to building RxSwift as a Dynamic Library.

If you wish to build RxSwift as a Static Library using Carthage you may use the script below to manually modify the framework type before building with Carthage:

carthage update RxSwift --platform iOS --no-build
sed -i -e 's/MACH_O_TYPE = mh_dylib/MACH_O_TYPE = staticlib/g' Carthage/Checkouts/RxSwift/Rx.xcodeproj/project.pbxproj
carthage build RxAlamofire --platform iOS

Swift Package Manager

Create a Package.swift file.

// swift-tools-version:5.0

import PackageDescription

let package = Package(
  name: "RxTestProject",
  dependencies: [
    .package(url: "https://github.com/ReactiveX/RxSwift.git", from: "5.0.0")
  ],
  targets: [
    .target(name: "RxTestProject", dependencies: ["RxSwift", "RxCocoa"])
  ]
)

$ swift build

To build or test a module with RxTest dependency, set TEST=1.

$ TEST=1 swift test

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

Wassmd/RxSwift