RxOptional

RxSwift extentions for Swift optionals and "Occupiable" types.

Usage

All operators are available on Driver as well unless otherwise marked.

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

fatalErrorOnNil

During release builds fatalErrors are logged. Durring Debug builds .fatalErrorOnNil() sends Error event for Observables and Driver continutes after logging fatalError.

Observable<String?>
    .of("One", nil, "Three")
    .fatalErrorOnNil()
    .subscribe { print($0) }

Next(One)
fatal Error: Found nil while trying to unwrap type <Optional<String>>
Error(Found nil while trying to unwrap type <Optional<String>>)

errorOnNil

Unavailable on Driver. By default errors with RxOptionalError.FoundNilWhileUnwrappingOptional.

Observable<String?>
    .of("One", nil, "Three")
    .errorOnNil()
    .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

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 always conform custom types to Occupiable.

filterEmpty

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

Next(["Single Element"])
Next(["Two", "Elements"])
Completed

fatalErrorOnEmpty

During release builds fatalErrors are logged. Durring Debug builds .fatalErrorOnEmpty() sends Error event for Observables and Driver continutes after logging fatalError.

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

Next(["Single Element"])
fatal Error: Empty occupiable of type <Array<String>>
Error(Empty occupiable of type <Array<String>>)

errorOnEmpty

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

.catchOnEmpty guarantees that the hander function returns a Observable or Driver with non-empty elements by calling .errorOnEmpty or .fatalErrorOnEmpty respectfully.

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
• Open Examples.playground
• Show Debug Area (cmd+shit+Y)
• Click blue play button in Debug Area

Requirements

• RxSwift
• RxCocoa

Installation

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

pod "RxOptional"

Author

Thane Gill, me@thanegill.com

License

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