MY AFFAIR

REACTIVECOCOA

with

FUNCTIONAL

REACTIVE

PROGRAMMING

FUNCTIONAL REACTIVE PROGRAMMING

// Imperative programming

var x = 1, y = 2, z = y + x;console.log(z); //3x = 2;console.log(z); //3

// Reactive programming

var x = 1, y = 2, z = y + x;console.log(z); //3x = 2;console.log(z); //4

FUNCTIONAL

PROGRAMMINGREACTIVE

FUNCTIONAL PROGRAMMING

DECLARATIVE EVALUATION OF PURE FUNCTIONS TO CREATE IMMUTABLE

PROGRAMS AND SO AVOID SIDE EFFECTS THAT ARE EXTERNALLY

OBSERVED.

PURE FUNCTIONS

DECLARATIVE PROGRAMMING

REFERENTIAL TRANSPARENCY

INMUTABILITY

// Imperative programming

var arrayFoo = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];for (var i = 0; i < arrayFoo.length; i++) { arrayFoo[i] = Math.pow(arrayFoo[i], 2);}array; // [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

// Declarative programming

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9].map(num => Math.pow(num, 2));// [0, 1, 4, 9, 16, 25, 36, 49, 64, 81]

PURE FUNCTIONS

DECLARATIVE PROGRAMMING

REFERENTIAL TRANSPARENCY

INMUTABILITY

// Impure function

var likes = 0;function addLike() { return ++likes;}

// Pure function

function addLike(likes) { return ++likes;}addLike(addLike(0)); // 2

DECLARATIVE PROGRAMMING

REFERENTIAL TRANSPARENCY

INMUTABILITY

PURE FUNCTIONS// Referential transparent function

int plusOne(int x){ return x+1;}

// Referential opaqueness function

int G = 10;

int plusG(int x){//G can be modified externally returning different values. return x + G;}

DECLARATIVE PROGRAMMINGREFERENTIAL TRANSPARENCY

INMUTABILITY

PURE FUNCTIONS

// Referential transparent function

int plusOne(int x){ return x+1;}

// Referential opaqueness function

int G = 10;

int plusG(int x){//G can be modified externally returning different values. return x + G;}

REACTIVE PROGRAMMING

FUNCTIONAL

: https://goo.gl/NaMmJ

: https://goo.gl/sGSwMS

Reactive programming is programming with asynchronous data streams.

A stream is a sequence of ongoing events ordered in time.

HANDS ON!

// RxSwift LoginViewModel

struct LoginViewModel { let usernameBGColor: Driver<UIColor> let passwordBGColor: Driver<UIColor> let credentialsValid: Driver<Bool> init(usernameText: Driver<String>, passwordText: Driver<String>) { let usernameValid = usernameText .distinctUntilChanged() .throttle(0.3) .map { $0.utf8.count > 3 } let passwordValid = passwordText .distinctUntilChanged() .throttle(0.3) .map { $0.utf8.count > 3 } usernameBGColor = usernameValid .map { $0 ? BG_COLOR : UIColor.white } passwordBGColor = passwordValid .map { $0 ? BG_COLOR : UIColor.white } credentialsValid = Driver.combineLatest(usernameValid, passwordValid) { $0 && $1 } } func login(_ username: String, password: String) -> Observable<AutenticationStatus> { return AuthManager.sharedManager.login(username, password: password) }