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

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Is this too much work for a Gateway to do?

I'm writing a Gateway class that wraps access to a web service which provides information about a player's item inventory in a video game. This web service returns a variety of information, however I ...
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924 views

DDD, modularizing the application and domain layers without breaking the DIP

Quoting DDD theory: The application layer is thin in terms of domain logic - it merely coordinates the domain layer objects to perform the actual work. When it comes to modularization, and ...
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4k views

Is this a good Visual Studio solution structure for a domain driven design RESTful web service?

I am building a .NET 4.5 C# Web API RESTful solution and I would like someone to tell me if my project solution is correct and/or wise(-enough?) for a solution designed using Domain Driven Design, ...
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336 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 ...
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401 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 ...
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394 views

Should I be using separate 'domain' layer?

I have been reading a lot about domain layer and DDD. However I am still confused about it. To me they seem to be a fancy name for business classes however more modelled towards your application ...
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1k views

DDD and the persistence of value objects; must we denormalize?

I've been reading up a lot on Domain-Driven Development, and I came to the question of how to preserve lack of distinct identity with value objects (VOs). While in the DDD world, this is a requirement ...
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868 views

Breaking the “ubiquitous language” by having an IoC Container in Domain Model?

I am a bit new to DDD and bear with me if my understanding seems way off. My question is about Udi's solution to domain events, particularly the class DomainEvents (see code below) An excerpt from ...
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914 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 ...
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442 views

How to define the seams between the domain layer and a database full of stored procedures?

We have a legacy database full of stored procedures. These stored procedures are somewhat CRUD-categorized but upon inspection of some procedures, they are not "simple" as they might update, delete, ...
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82 views

Domain Driven Design and Cross Domain interaction

I am a relative DDD newbie, but I am reading anything and everything I can get my hands on to boil out and distill my knowledge. I came across this DDD question, and one of the answers has me ...
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123 views

DDD – duplicity between Aggregates – should I use one table?

I understand that there exists duplicity of data between Bounded Contexts. The thing is that I'm not really sure about duplicity of data between Aggregate roots. Example: I have product in Product ...
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485 views

When is it appropriate to map a DTO back to its Entity counterpart

From what I've read and implemented, DTO is the object that hold a subset of value from a Data model, in most cases these are immutable objects. What about the case where I need to pass either new ...
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1answer
139 views

DDD models and localization?

Let's say I have a Book that has it's title and description localized in any number of languages. Localization only matters for e.g. administrators, because users chooses their localization and they ...
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1k views

Should I use the repository in the Domain Object or push the Domain Object back to the Service Layer?

I have come from a transaction script world and I am just starting to take a look at DDD. I am unsure of the correct way to integrate a DDD design with database persistence. This is what I have: A ...
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481 views

Architecting multi-model multi-DB ASP.NET MVC solution

I have an ASP.NET MVC 4 solution that I'm putting together, leveraging IoC and the repository pattern using Entity Framework 5. I have a new requirement to be able to pull data from a second database ...
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507 views

A design decision in composition or aggregation

I've recently had doubts about some design decisions that I frequently make, so this time I decided to take some time and try to analyze it to find the best solution. I will describe a simple scenario ...
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487 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 ...
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184 views

Microservices architecture and bounded contexts

In the past few days I've been reading some things about microservices architecture. I didn't get the whole point yet, since I'm just starting with this, but there's one point which caught my ...
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176 views

DDD design question

I have a question on modelling an Entity\Aggregate root in DDD. I am refactoring a project that uses Entity Framework and business logic as services, the services contain lot of logic which I believe ...
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2k views

Domain driven design and WCF services architecture

I am trying to figure out how to architecture my project in the DDD paradigm (a complete beginner in DDD) and stumbled upon a problem about the implementation of the web services... These are some ...
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1answer
2k views

DDD: Domain Model Factory Design

I am trying to understand how and where to implement domain model factories. I have included my Company aggregate as a demo of how I have done it. I have included my design decisions at the end - I ...
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1answer
208 views

OOP, domain models, and the user

When developing domain models, I can see two major ways of thinking about the user: The first one assumes that a program is a kind of "simulation" of what happens in the real world, and the user is ...
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3answers
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Ensuring transactional consistency with DDD

I am starting out with DDD and understand that aggregate roots are used to ensure transnational consistency. We should not modify multiple aggregates in one application service. I would like to know ...
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107 views

How to model Aggregate Roots for this music event system?

Let's say I am modeling a music event system. I have: music events listing events (the items in a lineup) - a listing event has acts (the artists playing in an item in the lineup - these can be ...
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1k views

Fire domain events after transaction completes

I am trying to implement a domain event system that only fires its events when the associated unit-of-work commits successfully. The main reason why I want to do this is because I have other ...
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369 views

Use a custom value object or a Guid as an entity identifier in a distributed system?

tl;dr I've been told that in domain-driven design, an identifier for an entity could be a custom value object, i.e. something other than Guid, string, int, etc. Can this really be advisable in a ...
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431 views

DDD and filtering

I am developing an app in ddd maner. So I have a complex domain model. Suppose I have a Fare object and Airline. Each Airline should contain several or much more Fares. My UI should represent Model ...
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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 ...
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1answer
558 views

Aggregate Root and Lots of Data Efficiency

It's more of a scenario, but it isn't far fetched at all. Let's say I have an Aggregate Root (AR) Warehouse which it's used to manage product stock. The Product itself is an AR in a different bounded ...
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DDD + POCO does this makes sense?

DDD promotes rich domain models with behavior in it, POCO naked objects without any objects in it. Is it possible to have them both combined? I have a Multi Layer Solution Core - has POCO ...
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663 views

What is the business cost of anemic domain model

I am looking to quantify the cost or problems of bad software development practices. Specifically can software that has been developed resulting in an anemic domain model be quantifiable in terms of ...
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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” ...
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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 ...
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Domain driven design, can two aggregates have the same root?

For the purpose of separating different functionality into different classes, I have two following Aggregates: ActiveEmployee AssignTask () ReassignManager () Deactivate (string reason) ...
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489 views

Is depending on lazy loading a code smell?

During my short experience with DDD I often find myself in the situation where I wished for some type of lazy loading mechanism to solve some dangerous cases where large nested data sets might be ...
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2answers
539 views

DDD - Domain Object calling a web service

Is it ok to call a webservice from a Domain object?. As I write the question I am thinking that you should never do that, as it is poor design, but the situation is the following: I have a domain ...
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288 views

How to start using DDD in designing a “library” application

I want to design an online book reader. The first step is describing all the use cases which I have listed below: I should be able to search a book by title. I should be able to borrow a book. I ...
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How to work with large aggregate roots?

I'm learning DDD and yet I have more questions than answers. Let's consider a model of a directory containing enormous number of files. Here is how I see it: Directory is an Aggregate root. This ...
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544 views

OOP what is meant by object-to-object communication

I've been reading in basic concepts of OOP,as i'm trying to make this shift from transactional scripts to more oop manner in php, and i often come across this definition : An object stores its ...
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Should we mock entities and value objects when doing DDD?

After reading a few articles about Newable vs Injectable objects and how these concepts relate to DDD's services, entities and value objects, I was left with some doubts about using newables in my ...
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1answer
109 views

Handling ground-breaking changes in a production system - Insert intermediate level Management object

As our client request, we are proceeding to change the base of our system. We already have the following structure: A class has many students. (simple typical one - to - many) Now we must change ...
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Presentation VS Application layer in DDD

I have trouble drawing a clear line between Presentation and Application layer in Domain Driven Design. Where should Controllers, Views, Layouts, Javascript and CSS files go? Is it in the ...
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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 ...
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3answers
242 views

What is business logic code and what is data access code, and what's the difference?

I ask this because it seems people usually consider the code that goes into a DAO or Repository implementation as "data access code", while the code that directly uses these DAOs/Repositories as ...
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1answer
256 views

Single source of truth within an enterprise distributed system

Within an enterprise distributed system I have many services - an ecommerce service, a CRM, support desk, finance, billing. Many of these services share common data, such as Customer data. These ...
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2answers
391 views

Should a domain object wrap/contain a DTO interface?

Using .NET - I have an interface IPerson. This interface is implemented by classes in multiple, separate repositories, e.g. EF6 (EfPerson), custom SQL (SqlPerson), or even custom assembly connecting ...
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How Add/Create* commands should be handled in CQRS + Event Sourcing architecture

I want to implement my first application using CQRS pattern along with Event Sourcing. I am wondering how creation of aggregate roots should be handled properly. Let's say someone sends CreateItem ...
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1answer
395 views

How a .NET dev team should be designing and delivering greenfield projects? [closed]

Some of the hottest topics in the software world atm are: Domain-Driven Design SOLID principles Agile methodologies ORM Now assuming that you are not currently using all of these in your team, ...
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607 views

DDD - Aggregate root with large number of children

I'll preface this question by saying I am relatively new to DDD so I may be making some fundamental mistakes here! I working on a project which involves the concepts of Accounts and Transactions (in ...