Awesome

STDevRxExt

Example

To run the Example.playground, clone the repo, and run pod install from the Example directory first.

Requirements

• iOS 9.0+
• tvOS 9.0+
• macOS 10.10+
• watchOS 3.0+
• Swift 5.0+
• Xcode 11+

Installation

List of All Extensions

• Filter Extensions
• Map Extensions
• Cast Extensions
• Other Extensions
• more coming soon

Filter Extensions

Allow only true elements from Observable<Bool>:

let disposeBag = DisposeBag()

Observable.of(true, false, false, true, true)
    .allowTrue()
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

Output will be:

true
true
true

You can use allowTrue on Bool? as well. In this case nil elements will be ignored:

let disposeBag = DisposeBag()

Observable.of(true, false, nil, true, nil, true)
    .allowTrue()
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

Output will be:

true
true
true

If you prefer to allow nil elements as well then you can use allowTrueOrNil like this:

let disposeBag = DisposeBag()

Observable.of(true, false, nil, true, nil, true, false)
    .allowTrueOrNil()
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

Output will be:

true
true
true
true
true

Map Extensions

You can map every element in sequence with provided value.

let disposeBag = DisposeBag()

Observable.of(1, 5, 7, 8)
    .map(to: "ping")
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

Output will be:

ping
ping
ping
ping

You can map every element in sequence by procided Key Path.

let disposeBag = DisposeBag()

   let observable = Observable.of(
            Book(title: "Twenty Thousand Leagues Under the Sea", author: Author("Jules", "Verne")),
            Book(title: "Hamlet", author: Author("William", "Shakespeare")),
            Book(title: "Hearts of Three", author: Author("Jack", "London"))
        )

    observable
        .map(at: \.title)
        .subscribe(onNext: { print($0) })
        .disposed(by: disposeBag)

    observable
        .map(at: \.author.firstName)
        .subscribe(onNext: { print($0) })
        .disposed(by: disposeBag)

Output will be:

Twenty Thousand Leagues Under the Sea
Hamlet
Hearts of Three

Jules
William
Jack

Cast Extensions

You can do downcast elements in sequence using cast(to:).

let disposeBag = DisposeBag()

Observable<CustomStringConvertible>.of("1", "5", "7", "8")
    .cast(to: String.self)
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

Output will be:

Optional("1")
Optional("5")
Optional("7")
Optional("8")

In order to do force downcast use forceCast(to:) liek this:

let disposeBag = DisposeBag()

Observable<CustomStringConvertible>.of("1", "5", "7", "8")
    .forceCast(to: String.self)
    .subscribe(onNext: { print($0) })
    .disposed(by: disposeBag)

Output will be:

1
5
7
8

In case of downcast exception it will return Observable.error(RxCastError.castFailed).

Allow extension functions can be used on Driver as well, except forceCast(to:).

Other Extensions

Sometimes we need to update some subject or observer on each next event of Observable or Driver. For example:

request
    .do(onNext: { [weak self] _ in
        self?.inProgress.onNext(true)
    })
    .flatMap {
        service.doRequest($0)
    }
    .do(onNext: { [weak self] _ in
        self?.inProgress.onNext(false)
    })
    .subscribe(onNext: { response in
        dump(response)
    })
    .disposed(by: disposeBag)

You can use update(_:with:) method for shorting code like this:

request
    .update(inProgress, with: true)
    .flatMap {
        service.doRequest($0)
    }
    .update(inProgress, with: false)
    .subscribe(onNext: { response in
        dump(response)
    })
    .disposed(by: disposeBag)

Author

Tigran Hambardzumyan, tigran@stdevmail.com

Support

Feel free to open issues with any suggestions, bug reports, feature requests, questions.

Let us know!

We’d be really happy if you sent us links to your projects where you use our component. Just send an email to developer@stdevmail.com And do let us know if you have any questions or suggestion.

License

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