Domain-driven design (DDD) is an approach to develop software for complex needs by connecting the implementation to an evolving model.

learn more… | top users | synonyms (1)

1
vote
1answer
193 views

When do domain concepts become application constructs?

I recently posted a question regarding recovering a DDD architecture that became an anemic domain model into a multitier architecture and this question is a follow-on of sorts. My question is when ...
4
votes
3answers
2k views

DDD and Value Objects. Are mutable Value Objects a good candidate for Non Aggr. Root Entity?

Here is a little problem Have an entity, with a value object. Not a problem. I replace a value object for a new one, then nhibernate inserts the new value and orphan the old one, then deletes it. Ok, ...
1
vote
1answer
636 views

Is there a clean separation of my layers with this attempt at Domain Driven Design in XAML and C#

I'm working on an application. I'm using a mixture of TDD and DDD. I'm working hard to separate the layers of my application and that is where my question comes in. My solution is laid out as ...
5
votes
2answers
419 views

Keeping a domain model consistent with actual data

Recently domain driven design got my attention, and while thinking about how this approach could help us I came across the following problem. In DDD the common approach is to retrieve entities (or ...
3
votes
4answers
2k views

DDD: Service or Repository

I am developing an app in DDD manner. And I have a little problem with it. I have a Fare (airline fare) and FareRepository objects. And at some point I should load additional fare information (from a ...
6
votes
1answer
427 views

DDD: service contains two repository

Does it correct way to have two repository inside one service and will it be an application or domain service? Suppose I have a Passenger object that should contains Passport (government id) object. ...
1
vote
1answer
552 views

DDD Model Design and Repository Persistence Performance Considerations

So I have been reading about DDD for some time and trying to figure out the best approach on several issues. I tend to agree that I should design my model in a persistent agnostic manner. And that ...
3
votes
1answer
1k views

How to manage long running background threads and report progress with DDD

Title says most of it. I have found surprising little information about this. I have a long running operation of which the user wants to see the progress (as in, item x of y processed). I also need to ...
3
votes
1answer
1k views

Recovering an anemic domain model into a multitier architecture

I have spent the past several days learning about domain driven design and attempting to apply it to a current project. I decomposed the problem domain into the canonical logical components: domain, ...
18
votes
1answer
4k views

How to choose between using a Domain Event, or letting the application layer orchestrate everything

I'm setting my first steps into domain driven design, bought the blue book and all, and I find myself seeing three ways to implement a certain solution. For the record: I'm not using CQRS or Event ...
5
votes
6answers
406 views

In a team practicing Domain Driven Design, should the whole team participate in Stakeholder meetings?

In my experience, a Software Development Team that comprises: 1 Project Manager 1 Tech Lead 1 - 2 Senior Dev 2 - 3 Junior Dev (Fresh grad) Only the Tech Lead & PM (and/or Senor Dev/s) will ...
3
votes
2answers
905 views

Can the following Domain Entity contain logic for creating/deleting other entities?

a) As far as I understand it, in most cases Domain Model DM doesn't contain code for creating/deleting domain entities, but instead it is the job of layers ( ie service layer or UI layer ) on top of ...
6
votes
6answers
588 views

Should a domain expert make class diagrams?

The domain expert in our team uses UML class diagrams to model the domain model. As a result, the class diagrams are more of technical models rather than domain models (it serves of some sort of ...
10
votes
4answers
4k views

Accessing Repositories from Domain

Say we have a task logging system, when a task is logged, the user specifies a category and the task defaults to a status of 'Outstanding'. Assume in this instance that Category and Status have to be ...
1
vote
1answer
331 views

design pattern advice: graph -> computation

I have a domain model, persisted in a database, which represents a graph. A graph consists of nodes (e.g. NodeTypeA, NodeTypeB) which are connected via branches. The two generic elements (nodes and ...
3
votes
1answer
920 views

Domain Models (PHP)

I have been programming in PHP for several years and have, in the past, adopted methods of my own to handle data within my applications. I have built my own MVC, in the past, and have a reasonable ...
6
votes
3answers
628 views

Resources for popular domain models [closed]

I have come across many situations where I had to build a system for a library or a clinic or other popular domains. The thing is a domain model for a library was probably done 1000 times already with ...
8
votes
10answers
790 views

Should an image be able to resize itself in OOP?

I'm writing an app that will have an Image entity, and I'm already having trouble deciding whose responsibility each task should be. First I have the Image class. It has a path, width, and other ...
6
votes
2answers
473 views

DDD / Layers and legacy systems

I have to refactor a complex C# app (many dialogs, mixed logic and so on). There is a part managing the communication with special hardware equipments (sending commands and receive data via ...
5
votes
1answer
585 views

Is it Ok if Domain Object cross Service Boundary

Is it Ok if Domain Object cross Service-Boundary? Everyone recommend that only DTO should be returned by Services. I am creating simple CRUD application. Is it ok if my service methods return ...
1
vote
2answers
367 views

Are factors such as Intellisense support and strong typing enough to justify the use of an 'Anaemic Domain Model'?

It's easy to accept that objects should be used in all layers except a layer nominated as a data layer. However, it's just as easy to end-up with an 'anaemic domain model' that is just an object ...
4
votes
4answers
965 views

Justification for bidirectional relationship

I typically try and avoid bidirectional relationships at all costs. Recently I've been trying to follow a more domain centric design philosophy and I'm looking for advice in the best way to solve a ...
17
votes
3answers
8k views

MVVM, DDD, and WPF Layered Application Project Structure Guidance

I am trying to setup my application's structure in VS and I want to "try" and future proof it to a reasonable level. This application will be a WPF re-write of an old Winform app that had followed no ...
3
votes
7answers
2k views

Inheritance using non-abstract base class

This post is based on the question http://stackoverflow.com/questions/49002/prefer-composition-over-inheritance/11758048#comment15634305_11758048. Some people said - check whether there is “is-a” ...
4
votes
2answers
509 views

Domain Objects with Interfaces

I'm in a situation where part of my system has a dependency on another module in the same system, but the modules themselves need to remain independently deployable, where the parts they depend on ...
4
votes
2answers
1k views

Distributed application using RabbitMQ

I am on my way to create an application with 4 bounded context using CQRS & event sourcing. In order to make these bounded context talk to each other I was planning on using Rabbit MQ. My ...
4
votes
1answer
2k views

CQRS + Event Sourcing: (is it correct that) Commands are generally communicated point-to-point, while Domain Events are communicated through pub/sub?

Didn't know how to shorten that title. I'm basically trying to wrap my head around the concept of CQRS ( http://en.wikipedia.org/wiki/Command-query_separation) and related concepts. Although CQRS ...
10
votes
3answers
5k views

DDD, Saga & Event-sourcing: Can a Compensate Action simply be a delete on the event store?

I realize the above question probably raises a few 'what??'s, but let me try to explain : I'm trying to wrap my head on a couple of related concepts, basically the Saga-pattern ( ...
8
votes
2answers
2k views

Are Persistence-Ignorant objects able to implement lazy loading?

Persistence Ignorance is an application of single responsibility principle, which in practice means that Domain Objects (DO) shouldn't contain code related to persistence, instead they should only ...
3
votes
2answers
2k views

Should this code/logic be included in Business Objects class or a separate class?

I have created a small application which has a three tier architecture and I have business object classes to represent entities such as User, Orders, UserType etc. In these classes I have methods that ...
2
votes
2answers
4k views

What is a best practice tier structure of a Java EE 6/7 application?

I was attempting to find a best practice for modeling the tiers in a Java EE application yesterday and couldn't come up with anything current. In the past, say java 1.4, it was four tiers: ...
4
votes
2answers
2k views

Equivalent of Domain Driven Design for functional programming languages

I really love the idea of domain driven design, however, as I'm learning Go, I'm wondering if there's the equivalent of DDD that's aimed at an effectively more functional language?
1
vote
2answers
368 views

Designing a hierarchical structure with lots of reads and writes?

I am in the process of working on a video on demand system part of it involves the management of a hierarchical tree structure (think windows explorer) which allows users to upload videos, move ...
9
votes
2answers
620 views

How to make this design closer to proper DDD?

I've read about DDD for days now and need help with this sample design. All the rules of DDD make me very confused to how I'm supposed to build anything at all when domain objects are not allowed to ...
2
votes
2answers
862 views

Web workflow solution - how should I approach the design?

We've been tasked with creating a web based workflow tool to track change management. It has a single workflow with multiple synchronous tasks for the most part, but branch out at a point to tasks ...
0
votes
1answer
551 views

DDD identifying aggregate root

I am designing the a web application using domain driven design.I have following scenario: Each applicationGroup can have one Application and each application can have multiple configuration.I am ...
3
votes
2answers
375 views

Developing the Domain Model alone

In DDD examples it seems the common method for developing the domain model is to sit with domain experts and iterate over versions of the model, say on a whiteboard, continually modifying it and ...
4
votes
3answers
776 views

Scrum, DDD, and front-end development in an enterprise environment

So, I've been working for a bank for the past 4 years. My main responsibility has been online banking. Over the past year, we've been implementing the scrum methodology. We've also changed to domain ...
10
votes
3answers
3k views

Validation and authorization in layered architecture

I know you are thinking (or maybe yelling), "not another question asking where validation belongs in a layered architecture?!?" Well, yes, but hopefully this will be a little bit of a different take ...
11
votes
4answers
4k views

When should an Aggregate Root contain another AR (and when should it not)

Let me begin by first apologizing for the length of the post, but I really wanted to convey as much detail up-front so I don't take your time going back and forth in comments. I am designing an ...
2
votes
1answer
610 views

Drawback of implementing DDD service as static class?

Can Services in a domain-driven design be implemented as C# static class? What are the drawbacks of this choice? Can it be implemented as a non-singleton non-static class?
4
votes
4answers
356 views

How to decide whether to implement an operation as Entity operation vs Service operation in Domain Driven Design?

I am reading Evans's Domain Driven Design. The book says that there are entity and there are services. If I were to implement an operation, how to decide whether I should add it as a method on an ...
9
votes
6answers
18k views

Application layer vs domain layer?

I am reading Domain-Driven Design by Evans and I am at the part discussing the layered architecture. I just realized that application and domain layers are different and should be separate. In the ...
18
votes
5answers
2k views

Do ORMs enable the creation of rich domain models?

After using Hibernate on most of my projects for about 8 years, I've landed on a company that discourages its use and wants applications to only interact with the DB through stored procedures. After ...
1
vote
1answer
555 views

DDD and validation of aggregate root

Suppose an aggregate root : MailConfiguration (wrapping an AddressPart object). The AddressPart object is a simple immutable value object with some fields like senderAdress, recipentAddress (to make ...
1
vote
1answer
92 views

Question about state and domain objects

Suppose I create a domain object called UserAdministration, if i have a method called CreateUser how would i pass state to this method, would I create properties on the UserAdministration object and ...
3
votes
1answer
1k views

Forcing aggregate root child access through the aggregate root alone

Context I'm developing an application using a Domain Driven Design approach. I want to use a design pattern wherever appropriate and apply all SOLID principles. Scenario I have an order and I want ...
4
votes
1answer
1k views

what does “domain” mean when referring to DDD

What does the word domain mean regarding driven design/development? Not in terms of semantics or a scholarly definition but in terms of how it modifies processes or philosophies? I was reading a ...
4
votes
2answers
419 views

How should I include third-party models in my domain model?

I'm currently trying to design a little application using Domain Driven Design but I'm afraid I don't really get the concept yet. Let me try to explain this as clearly as possible. public interface ...
7
votes
3answers
422 views

Computed Values and Simple Reads - A nagging pain for my Domain Driven Designs!

The problem I continually face is how to deal with computed values driven by domain logic while still working efficiently against the data store. Example: I'm returning a list of Products from my ...