2017-12-15 December learning session

Date

Dec 15, 2017

Attendees

@Sebastian Brudziński
@Nikodem Graczewski (Unlicensed)
@Mateusz Kwiatkowski
@Łukasz Lewczyński (Deactivated)
@Paweł Albecki (Deactivated)

Goals

Watch learning material Domain-Driven Design in Practice
(https://www.pluralsight.com/courses/domain-driven-design-in-practice) - Extending the Bounded Context with Aggregates, Introducing the Second Bounded Context
Discuss watched materials and compare to how things are handled in OpenLMIS - are there any ideas/approaches/workflows we can adopt in OpenLMIS?

Discussion

Aggregates:
- Requisition - root entity
  - line item - entity
    - Line items should not be available outside of Aggregate.
    - Getter should return immutable list of immutable objects or no getter, line items should be updatable through Requisition Aggregate.
    - Setter should be removed.
    - Line item should not have id in DTO.
  - Value Objects - worth having (discussion already on Dev Group)
- Order
  - POD has Order, Order has line item, POD line item has order line item.
  - Order line item should not be referenced from outer context.
- Proof of Delivery
  - for every line item values of quantity shipped, quantity received, quantity returned, replaced product code.
  - How to get order line item details on ui? e.g. by orderable code.
Bounded Context - follow up from previous learning meeting discussion, solution space
Sub-domains - problem space

Wrap up

We have asked every participant to give a score on how useful this meeting was and how helpful this specific material was. The voting was anonymous and each participant could give a score from 1 (useless) to 10 (very useful).
The averages were:

How useful are those meetings: 8/10
How useful was this specific material?

Extending the Bounded Context with Aggregates: 8.2/10
Introducing the Second Bounded Context: 6.8/10

Final thoughts

It's worth to consider using AggregateRoot, ValueObject superclass/interface.
Getters should return immutable list of immutable objects or should be not implemented.

Action items

@Mateusz Kwiatkowski to start discussion about separate resource for requisition for approval.

@Łukasz Lewczyński (Deactivated) to create ticket for order line item should not be referenced from outer context (POD). → https://openlmis.atlassian.net/browse/OLMIS-3827

@Paweł Albecki (Deactivated) to follow up with requisition line items should not be available outside of Requisition Aggregate.