I believe web developers only care about printing out HTML as quick as possible. They don't care about fancy algorithms And so I want to tell you about something that makes your code a little bit more elegant Workflows

1. Workflows
The Rise Of The Machines
!
" wengerk
wengerk

2. Journey
• Theory
• Real-world Workflow Examples
• Implementations
• Going Further
• Identifying Processes in your App

3. I believe web developers only care about printing out HTML as
quick as possible. They don't care about fancy algorithms
And so I want to tell you about something that makes your
code a little bit more elegant

4. A way of thinking

5. Why ?
• Separates business from you models
• Makes the code more:
• Reusable
• Maintainable
• Readable

6. So how ?

7. Graph Theory

8. Graph Theory

9. Graph Theory

10. Graph Theory

11. Graph Theory
5

12. Graph Theory

13. Graph Theory
A B
3
1
2 3
3
5
3
4
2
6
2
6
1
5
4
2
3
2
7

14. Graph Theory
A B
3
1
2 3
3
5
3
4
2
6
2
6
1
5
4
2
3
2
7

15. Graph Theory
A B
3
1
2 3
3
5
3
4
2
6
2
6
1
5
4
2
3
2
7

16. Graph Theory
A B
3
1
2 3
3
5
3
4
2
6
2
6
1
5
4
2
3
2
7

17. Graph Theory
3
1
2 3
3
5
3
4
2
6
2
6
1
5
4
2
3
2
7

18. if you've got a problem, if you can express this problem as a
graph problem, there's already a solution to it

19. Graph Theory
graph

20. Graph Theory

21. Graph Theory

22. Graph Theory
Graph
Tree
Workflow

23. Workflow

24. Workflow
A t0 B
T0
Place Transition Place

25. Workflow
A C
t0
B D
t1

26. State Machine
A C
t0a
B D
t1
t0b

27. State Machine
A C
B D
t0a
t0b
T1

28. State Machine
Graph
Tree
Workflow
State
Machine

29. Real-world Workflow Examples

30. Traffic Light
Green Yellow Red

31. Article
Review
Draft
Trash
Archived
Published
To review
Publish
Archive
Untrash Trash

32. Pull Request
Travis CI
Start
Merged
Review
Closed
Submit Update
Rejected
Wait for Review
Update
Coding
Reopened
Change
needed

33. Elevator Doors
Closing
Opened
Opening
Closed
Sensor opened
Sensor closed
Close
Open
Close
Open

34. State Machine Implementations

35. Traffic Light
Green Yellow Red

42. Hello Workflow

43. Functions
• Can we do [transition] ?
• Apply [transition]
• What state are we in ?
• Which are my valid transitions ?

44. Article
Review
Draft
Trash
Archived
Published
To review
Publish
Archive
Untrash Trash

45. Review
Draft
Trash
Archive
d
Publish
ed
To review
Publish
Archive
Untrash
Trash

46. Article
Review
Draft
Trash
Archived
Published
To review
Publish
Archive
Untrash Trash
Trash

48. Events

49. • workflow.leave
• workflow.[article].leave
• workflow.[article].leave.[draft]
• workflow.transition
• workflow.[article].transition
• workflow.[article].transition.[to_review]
• workflow.enter
• workflow.entered
• workflow.completed
• workflow.announce

50. Guards

52. Identifying Processes in your App

55. By using Workflow component
you will write
fewer bugs

56. A way of thinking