RxOptional

RxSwift extensions for Swift optionals and “Occupiable” types.

Usage

All operators are also available on Driver and Signal, unless otherwise noted.

Optional Operators

filterNil

Observable<String?>
    .of("One", nil, "Three")
    .filterNil()
    // Type is now Observable<String>
    .subscribe { print($0) }

next(One)
next(Three)
completed

replaceNilWith

Observable<String?>
    .of("One", nil, "Three")
    .replaceNilWith("Two")
    // Type is now Observable<String>
    .subscribe { print($0) }

next(One)
next(Two)
next(Three)
completed

errorOnNil

Unavailable on Driver, because Drivers cannot error out.

By default errors with RxOptionalError.foundNilWhileUnwrappingOptional.

Observable<String?>
    .of("One", nil, "Three")
    .errorOnNil()
    // Type is now Observable<String>
    .subscribe { print($0) }

next(One)
error(Found nil while trying to unwrap type <Optional<String>>)

catchOnNil

Observable<String?>
    .of("One", nil, "Three")
    .catchOnNil {
        return Observable<String>.just("A String from a new Observable")
    }
    // Type is now Observable<String>
    .subscribe { print($0) }

next(One)
next(A String from a new Observable)
next(Three)
completed

distinctUntilChanged

Observable<Int?>
    .of(5, 6, 6, nil, nil, 3)
    .distinctUntilChanged()
    .subscribe { print($0) }

next(Optional(5))
next(Optional(6))
next(nil)
next(Optional(3))
completed

Occupiable Operators

Occupiables are:

String
Array
Dictionary
Set

Currently in Swift protocols cannot be extended to conform to other protocols. For now the types listed above conform to Occupiable. You can also conform custom types to Occupiable.

filterEmpty

Observable<[String]>
    .of(["Single Element"], [], ["Two", "Elements"])
    .filterEmpty()
    .subscribe { print($0) }

next(["Single Element"])
next(["Two", "Elements"])
completed

errorOnEmpty

Unavailable on Driver, because Drivers cannot error out.

By default errors with RxOptionalError.emptyOccupiable.

Observable<[String]>
    .of(["Single Element"], [], ["Two", "Elements"])
    .errorOnEmpty()
    .subscribe { print($0) }

next(["Single Element"])
error(Empty occupiable of type <Array<String>>)

catchOnEmpty

Observable<[String]>
    .of(["Single Element"], [], ["Two", "Elements"])
    .catchOnEmpty {
        return Observable<[String]>.just(["Not Empty"])
    }
    .subscribe { print($0) }

next(["Single Element"])
next(["Not Empty"])
next(["Two", "Elements"])
completed

Running Examples.playground

Run pod install in Example directory
Select RxOptional Examples target
Build
Show Debug Area (cmd+shift+Y)
Click blue play button in Debug Area

Requirements

Installation

CocoaPods

RxOptional is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'RxOptional'

Carthage

Add this to Cartfile

github "RxSwiftCommunity/RxOptional" ~> 4.1.0

$ carthage update

Swift Package Manager

To use RxOptional as a Swift Package Manager package just add the following in your Package.swift file.

import PackageDescription

let package = Package(
    name: "ProjectName",
    dependencies: [
        .Package(url: "https://github.com/RxSwiftCommunity/RxOptional")
    ]
)

Author

Thane Gill, me@thanegill.com

License

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