RxTheme 6.0.0

RxTheme 6.0.0

Maintained by Carl, RxSwift Community.

Depends on:
RxSwift~> 6.0
RxCocoa~> 6.0

RxTheme 6.0.0


Build Status Version Carthage compatible License Platform


Define theme service

import RxTheme

protocol Theme {
    var backgroundColor: UIColor { get }
    var textColor: UIColor { get }

struct LightTheme: Theme {
    let backgroundColor = .white
    let textColor = .black

struct DarkTheme: Theme {
    let backgroundColor = .black
    let textColor = .white

enum ThemeType: ThemeProvider {
    case light, dark
    var associatedObject: Theme {
        switch self {
        case .light:
            return LightTheme()
        case .dark:
            return DarkTheme()

let themeService = ThemeType.service(initial: .light)

Apply theme to UI

// Bind stream to a single attribute
// In the way, RxTheme would automatically manage the lifecycle of the binded stream
view.theme.backgroundColor = themeService.attrStream { $0.backgroundColor }

// Or bind a bunch of attributes, add them to a disposeBag
    .bind({ $0.textColor }, to: label1.rx.textColor, label2.rx.textColor)
    .bind({ $0.backgroundColor }, to: view.rx.backgroundColor)
    .disposed(by: disposeBag)

All streams generated by ThemeService has share(1)

Switch themes

// When this is triggered by some signal, you can use:
someSignal.bind(to: themeService.switcher)

Other APIs

// Current theme type
// Current theme attributes
// Theme type stream
// Theme attributes stream

Extend binders in your codebase

Because RxTheme uses Binder<T> from RxCocoa, any Binder defined in RxCocoa could be used here.

This also makes the lib super easy to extend in your codebase, here is an example

extension Reactive where Base: UIView {
    var borderColor: Binder<UIColor?> {
        return Binder(self.base) { view, color in
            view.layer.borderColor = color?.cgColor

NOTICE: Since RxSwift 6, most variable based rx extensions should already been derived by @dynamicMemberLookup.

if you also want to use the sugar view.theme.borderColor, you have to write another extension:

extension ThemeProxy where Base: UIView {
    var borderColor: Observable<UIColor?> {
        get { return .empty() }
        set {
            let disposable = newValue
                .take(until: base.rx.deallocating)
                .observe(on: MainScheduler.instance)
                .bind(to: base.rx.borderColor)
            hold(disposable, for: "borderColor")

If you think your extension is commonly used, please send us a PR.


You can run the example project, clone the repo, run pod install from the Example directory first, and open up the workspace file.

If you prefer, there is also a nice video tutorial by @rebeloper.


5.x requires RxSwift 6, If you are using RxSwift 5, please use 4.x.


  1. File > Swift Packages > Add Package Dependency
  2. Add https://github.com/RxSwiftCommunity/RxTheme


pod 'RxTheme', '~> 5.0'


github "RxSwiftCommunity/RxTheme" ~> 5.0.0


duan, [email protected]


RxTheme is available under the MIT license. See the LICENSE file for more info.