iOSCon - Introduction to Functional Reactive Programming

1. Introduction to
Functional Reactive
Programming
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2. Functional Reactive
Programming
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3. Streams
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4. Stream
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5. Arrays
let values = [1, 2, 3, 4]
let doubledValues = values.map { $0 * 2 }
let higherThanTwo = values.filter { $0 > 2 }
let sum = values.reduce(0, +)
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6. Filter
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7. Combine Latest
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8. Chaining manipulations
let names = nameField.reactive.text
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9. Chaining manipulations
names.filter { $0.characters.count >= 3}
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10. Chaining manipulations
names.filter { $0.characters.count >= 3}
.map { return "Dear" + $0 }
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11. Chaining manipulations
let prefixedNames = names.filter { $0.characters.count >= 3}
.map { return "Dear" + $0 }
let combined = combineLatest(prefixedNames, surnames)
combined.observeValues { prefixedNames, surname in
print("Form input is (prefixedNames) (surname)")
}
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12. www.rxmarbles.com
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13. ReactiveSwift
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14. Events flow
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15. Non-Terminating
• Next
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16. Terminating
• Completed
• Failed
• Interrupted (Reactive Cocoa)
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17. This screen is a signal
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18. Represents events
over time
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19. Observe
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20. EliaszSawicki.com ( @EliSawic )

21. If you don't observe,
it's gone
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22. Observing
presentation.observeValues { idea in
remember(idea: idea)
}
presentation.observeCompleted {
print("Time for a break")
}
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23. Signal producer
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24. Represents a tasks
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25. Does not start it's
work if not asked
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26. Producing
presenter.startWithSignal { (signal, _) in
signal.observeValues { idea in
print(idea)
}
signal.observeCompleted {
print("Time for a break")
}
}
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27. Hot vs Cold
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28. Signal SignalProducer
presentation.observeValues presentation.startWithValues
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29. Signal SignalProducer
presentation.observeValues presentation.startWithValues
emits values all the time waits for your request
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30. Properties
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31. Bindings
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32. Binding example
let (slides, _) = Signal<Slide, NoError>.pipe()
label.reactive.text <~ slides.map { return "Slide: ($0.number)" }
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33. Memory Management
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34. Disposables
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35. Free your memory
let disposable = signal.observeValues { value in
...
}
deinit {
disposable.dispose()
}
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36. FUNctional reactive
programming
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