A cluster of associated objects that are treated as a unit for the purpose of data changes. External references are restricted to one member of the Aggregate, designated as the root. A set of consistency rules applies within the Aggregate's boundaries.
Questions tagged [aggregateroot]
441 questions
0
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1 answer
DDD - Aggregate context, consistency
I am trying to design a project management system students. Basically there is a given period of time in which a project has to be finished by students. Generally, students need to work on the project every day of the week which will be verified in…
navix1337
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1 answer
Should invariants be unit tested both in the application service and the aggregate root?
I got multiple value objects (VOs) inside my aggregate root (AR).
Each VO does invariant checks when created, such as string min/max length, regexp, etc.
Each VO is created when the AR is created and the AR is unit tested with 100% coverage.
Since…
Andrea Damiani
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Domain Driven Design - How does a reconstitution factory bypass invariants?
I'm having some difficulties figuring out how a reconstitution factory works when paired with DDD.
From what I understand, this factory would be owned by the repository layer (or rather, not the domain) and is simplified, as it expects all entities…
Nick N
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1 answer
DDD: Aggregate Root encapsulation with JavaScript
I can not find any clear example of how to implement Aggregate Root (DDD) with properly encapsulated its internal state with help of JavaScript/TypeScript. Below I suggest an idea on how to implement it. Maybe someone has ideas on how to improve…
Anton Komarov
- 103
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FluentNhibernate Map ValueObject
I have the following use case:
public class Object {
long Id
...
ISet tags
}
public class Tag : IEquatable {
string Label;
}
Object is an Aggregate Root and Tag a Value Object.
Both are stored in 2 different…
Ben D
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2 answers
DDD Aggregate Roots - How to Manage Invariants when I have references in my root to other Entities
I am new to DDD and I am designing a roommate matching system. One of my Aggregate Roots is a "Profile"
public class Profile
{
...
public Traits Traits { get; private set; }
public Traits Preferences { get; private set; }
...
}
As…
Jonathan
- 1
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How to unit test properly aggregate roots?
Let's consider the below example:
internal class Meeting
{
public int Id { get; set; }
}
internal class DailyRoomReservation
{
private ISet _meetings { get; set; } = new HashSet();
…
Lepruz
- 31
- 5
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votes
1 answer
Splitting nested entities keeping invariant within aggregates in DDD
I'm currently developing message imap-based module in crm app and i'm trying to connect dots using DDD principals.
I've started with three main entities, all bound under Account Aggregate:
Account - Email account. Has multiple Folders.
Folder -…
devmr97
- 1
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1 answer
Explicit State Modeling in DDD
I've been looking managing Root Aggregate state/life-cycle and found some content about the benefits of using Explicit State Modeling or Explicit Modeling over State Pattern, it's much cleaner and I like how I can let explicit concepts of my domain…
Mazen Elkashef
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Aggregate root id reference field naming convention
Let me assume that I have the 2 aggregates as below.
data class Order(
val id: OrderId,
val shipmentIds: Set
) : BaseAggregate() {}
data class Shipment(
val id: ShipmentId,
var fromAddress: ShippingAddress,
var…
Jay Ahn
- 73
- 5
0
votes
3 answers
Inter-aggregate references must use primary keys?
When I was reading Microservice Patterns, one of the paragraph says that Domain-Driven Design requires aggregate to follow some rules. One of the rule is "inter-aggregate references must use primary keys".
For example, it basically means that a…
johnlinp
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1 answer
DDD Aggregates vs Entities
What to do with an object that has two dependencies:
Let's say we have three objects: client, company and a contract.
Contract needs a client and a company to exist.
Naturally, business wise, the contract belongs more to the client than it does to…
Jesse
- 544
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2 answers
Search for aggregate root id
I try to bring Event Sourcing to my project but not sure how to do a specific thing in a less errorful way.
This is an "accounting" system but the main focus is on transactions, not on accounts. The thing is that I receive such events as withdrawal…
pepper
- 1,732
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1 answer
How should I handle multiple aggregates root interaction
I have read this post, in this post Udi Dahan talks about many to many relationships.
In that example he explains that in the case of a many to many relationship like the one a job would have with job boards, and taking into account the bounded…
rage77
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In REST, how to respond to POST of a sub-entity of which there can only be one, and one already exists?
I have a vehicles resource as the root entity of an aggregate. Each vehicle can have zero or one engines as a sub-resource/entity.
If vehicle #947 exists, but doesn't have an engine, I can say:
POST /vehicles/947/engines /* create an engine…
Jonathan M
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