Technically DDD

Transcript

2. Technically DDD DDDDeventer, 2017-07-06 19:45:00.000000
3. Pim Elshoff developer.procurios.com @pelshoff
6. Questions?
8. Context
9. Value objects
12. Value objects • Express a value • Business rules here • Immutable • Easy to unit test
13. Entities
15. Entities • Have identity • More than the sum of their attributes • Evolve over time • If there really really really is no VO possible, then business rules here • Slightly harder to test
16. Services
18. Services • No identity or attributes (Not a “thing”) • Cross-concern operations • Business rules that need more data than any single entity knows • Harder to test
19. Aggregates
21. Aggregates • Collection of objects • Interaction through root • If there really really really is no VO possible, then business rules here • Harder to test
22. Repositories
23. Repositories • Collection of all objects of a type
24. final class Address
25. final class BicycleService
26. final class StreetAddress
27. final class Investment
30. Meetings cannot end before they start
36. Program slots cannot occur in the same room at the same time
45. Program slots must occur within the duration of the meeting
47. Pim Elshoff developer.procurios.com @pelshoff