Functional Reactive Programming

Transcript

1. Functional Reactive Programming

2. “Everything flows, nothing stands still.” Heraclitus

3. Streams of Events

4. Streams of Events • Fire and forget events are relatively

   easy to create.

5. Streams of Events • Fire and forget events are relatively

   easy to create. • UIs

6. Streams of Events • Fire and forget events are relatively

   easy to create. • UIs • Ajax posts

7. Streams of Events • Fire and forget events are relatively

   easy to create. • UIs • Ajax posts • Messaging queues

8. Processing Events

9. Processing Events • A little trickier

10. Processing Events • A little trickier • difficult to compose

11. Processing Events • A little trickier • difficult to compose

    • lots of plumbing

12. Processing Events • A little trickier • difficult to compose

    • lots of plumbing • Callback Hell

13. “We’re going to need a bigger boat.”

14. FRP • A model for values that vary over time

    • Originates from Haskell Community • Several different implementation styles • We are focusing on Microsoft’s ReactiveExtenions style

15. Observable

16. Observable • A marriage of Iterables and the Observer Pattern

17. Observable • A marriage of Iterables and the Observer Pattern

    • Typical Sequence functions - Map, Filter, Reduce, Take

18. Observable • A marriage of Iterables and the Observer Pattern

    • Typical Sequence functions - Map, Filter, Reduce, Take • Subscribe/OnNext

19. Observable • A marriage of Iterables and the Observer Pattern

    • Typical Sequence functions - Map, Filter, Reduce, Take • Subscribe/OnNext • Error Handling

20. Observable • A marriage of Iterables and the Observer Pattern

    • Typical Sequence functions - Map, Filter, Reduce, Take • Subscribe/OnNext • Error Handling • Timing function - Delay

21. Observable • A marriage of Iterables and the Observer Pattern

    • Typical Sequence functions - Map, Filter, Reduce, Take • Subscribe/OnNext • Error Handling • Timing function - Delay • Buffering - Last N events

22. Observable • A marriage of Iterables and the Observer Pattern

    • Typical Sequence functions - Map, Filter, Reduce, Take • Subscribe/OnNext • Error Handling • Timing function - Delay • Buffering - Last N events • Composable - SelectMany/FlatMap

23. Marble Diagrams

24. A Marble Diagrams

25. A Marble Diagrams

26. A B Marble Diagrams

27. A B Marble Diagrams

28. A B A.merge(B Marble Diagrams

29. A B A.merge(B Marble Diagrams

30. A B A.merge(B Marble Diagrams

31. A B A.merge(B Marble Diagrams

32. A B A.merge(B Marble Diagrams

33. A B A.merge(B Marble Diagrams

34. A B A.merge(B Marble Diagrams

35. A B A.merge(B Marble Diagrams

36. A B A.merge(B Marble Diagrams

37. A B A.merge(B Marble Diagrams

38. A B A.merge(B Marble Diagrams

39. Autocomplete • On Keyup • Get the value of the

    field • Only values of length 3 or more • Make remote call • Filter out bad response • Display results

40. Autocomplete in reality • On Keyup • Get the value

    of the field • Throttle to 500ms • Only values of length 3 or more • Skip duplicates • Make remote call • Filter out bad response • Display results

41. Demo Source code: https://github.com/Cicayda/yolk-examples