https://github.com/alisoftware/functionalvcdemo

Demo for the Functional ViewControllers concept in RxSwift
https://github.com/alisoftware/functionalvcdemo

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Demo for the Functional ViewControllers concept in RxSwift

• Host: GitHub
• URL: https://github.com/alisoftware/functionalvcdemo
• Owner: AliSoftware
• Created: 2016-11-14T22:42:15.000Z (over 8 years ago)
• Default Branch: master
• Last Pushed: 2016-11-15T00:55:05.000Z (over 8 years ago)
• Last Synced: 2025-01-05T08:51:19.710Z (about 2 months ago)
• Language: Swift
• Size: 260 KB
• Stars: 8
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# FunctionalVCDemo

This project is a sample app demonstrating the concept of Functional ViewControllers using `RxSwift`.

## Concept

A Functional ViewController is a ViewController that can be used as a function `func show(input: T) -> Observable`. It will display the ViewController to gather data from the user, wait for the user to validate, then emit a `.next` even on the returned `Observable` once validated.

## Advantages

This pattern is useful to integrate a ViewContoller is a functional workflow, abstracting away the fact that the ViewController is a UI component and instead treating it as an asynchronous function getting inputs and asynchronously returning an output.

## Concept example

Imagine you have some Functional VCs that can be exposed in those functions:

* `func pickImage() -> Observable`

* `func askTitle() -> Observable`

* `func askNote() -> Observable`

Each function presents a UIViewController, waits for the user to interact and validate (e.g. `pickImage` will present an `UIImagePickerController` and wait for the user to select an image), and asynchronously return the result (in case of `pickImage`, that's the `UIImage` obvously).

With this you can easily chain those functional VCs usng classic RxSwift reactive chains:

```swift

struct ImageDescription {

  let image: UIImage?

  let name: String?

  let note: Int?

}

var imageDesc: ImageDescription()

self.pickImage()

  .flatMap({ image in

    imageDesc.image = image

    self.askTitle()

  })

  .flatMap({ title in

    imageDesc.title = title

    self.askNote()

  })

  .subscribe(onNext: { note in

    imageDesc.note = note

    print(imageDesc)

  })

  .addDisposableTo(disposeBag)

```

This allows to read the workflow like a chain of steps happening one after the other, hiding away the complexity of asynchronicity.