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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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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What is a value object in domain-driven design?

I have an entity and I've realised that there is a group of properties that work together. So, I moved them to a value object (together with their behavior) and now I have a reference from my entity ...
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295 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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236 views

Wouldn't Layer Supertype pattern corrupt our domain model?

a) To my knowledge Domain Objects should for the most part be oblivious to technical aspects of a design. Since I view class inheritance as being a technical solution, wouldn't introducing a Layer ...
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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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50 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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525 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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2answers
426 views

How far to go with Domain Driven Design?

I've read a little about domain driven design and the usage of a rich domain model, as described by Martin Fowler, and I've decided to put it in practice in a personal project, instead of using ...
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131 views

Ubiquitous Language and Custom types

Note that my question is referring to those attributes that even on their own already represent a concept ( ie on their own provide a cohesive meaning ). Thus such attribute needs no additional ...
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349 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 ...
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926 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 ...
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86 views

Reverse relationships for smaller/better Aggregates?

Let's take an example: we have two related entities, like Question and Choice. This is a poll: it contains of single question that may have 2 or more choices. Each choice can be voted for by users, ...
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719 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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561 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 ...
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613 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 ...
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182 views

Can a domain specific language be used to representing the Open SRD

I am in the early stages of creating an open source C# library that would allow developers to drop in the open SRD (http://www.d20srd.org/) into an existing project. Abstracted it is a complex set of ...
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163 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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779 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 ...
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676 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 ...
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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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399 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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82 views

Resources on securing domain models? [closed]

I'm have good resources on both security, domain modelling, and architecture patterns. I've noticed a distinct lack of any suggestion of how and where to integrate security into the systems I build. I ...
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3answers
248 views

How to completely avoid business logic in DAL?

In our ASP.NET MVC application, we try really hard to separate concerns to each layer (we use DDD). Nevertheless, it seems that we can't avoid having at least some business logic in DAL. For ...
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6answers
380 views

Object Design & Cohesion - Issue & potential refactoring

Abstract I have been trying to get my head around the cohesiveness of some functionality in our code base. I’ve approached this design in different ways, and lately I’m convinced that I took the ...
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240 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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Is there any reason to override Equals for an Entity?

An entity has identity, which implies there should only be one object (e.g. a particular customer) in memory. As such, reference equality (which is what the base version of object.equals checks for) ...
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365 views

Repository pattern implementation that knows nothing about the database table and column names

I've seen around the Internet and Github, implementations for the design pattern Repository that knows about database table and column names. I was think, if I want to work with the database as a ...
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302 views

Need help understanding UML diagram

I'm focusing on trying to understand UML diagrams and learning to interpret them in order to implement the designs they describe. In the following diagram, I am not clear on what the implementation ...
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1k views

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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961 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, ...
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150 views

Rich domain model and container services

I have a long experience in programming Java EE projects, but as I noticed most of the job I have done was with Transaction Script (anti)pattern. So I want to learn using a rich domain model, but ...
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212 views

Basic OOP Question for a Report

I'm in development of a sample project in Android for a friend's phone that keeps track of his sales. At first, one of the requirements was to create yearly reports of this sales data. This would be ...
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160 views

Does DDD make sense for apps which mostly present data?

I'm responsible for designing a dashboard and data manipulation front-end for a sale transaction database and am not quite sure what type of architecture to use. The database is populated by an ...
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369 views

Domain Driven Design with an EAV database model

How can one apply DDD to a EAV database model? Consider this EAV database model: How am I supposed to build a domain model if all my entities and their attributes will be stored in the database? ...
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94 views

DDD: Global unique identities vs surrogate

Let's start with an example: we have an entity: Book. It has unique identity: Isbn - a value object that wraps a String. This is an UUID. The Book entity also needs a surrogate id from the repo (sql ...
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246 views

Where to put format validation in a CQRS “stylish” domain model?

It feels right to put format validation inside the domain objects (VOs or entities) because it is the natural place for high cohesion and the domain knows best what every domain ...
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139 views

Does a repository belong in this project?

I have a project that gets all of its data from API calls. The server that hosts this API connects with it's own database (not even sure what DB it is, etc). More or less the idea of a repository is ...
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170 views

Choosing an ubiquitous language across different bounded contexts

If my domain has several Bounded Contexts, but only ONE team will work on all contexts, should I develop an Ubiquitous language for each context? or should I have only one and force to into all ...
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193 views

In DDD are Value Object always at the leaves of a relationship tree?

If I have a photo album where each Photo can be commented on, Should the Comments be Entities or Value Object in these cases: Comments can be added only anonymously (i.e. Comments have no relation ...
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322 views

Vernon's book Implementing DDD and modeling of underlying concepts

Following questions all refer to examples presented in Implementing DDD In article we can see from Figure 6 that both BankingAccount and PayeeAccount represent the same underlying concept of ...
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Identifying Domain Services & Application Services when doing DDD

-I'm trying to figure out how to identify Application Services in my application. I think I can identify a Domain service by 2 things: It acts as a facade to the repository. It holds business logic ...
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680 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 ...
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1answer
313 views

Should the domain model include all the domain entities in my project?

I have currently reading Grails and I love it. In order to get hands on experience with Grails I decided to create a web application for some Management System. Ya as you can guess there are plenty of ...
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Any examples of using Visio to document software?

I have Visio 2010 and want to learn how to use it to document software. Does anyone have examples of what Visio does well? Are there any things that Visio can do, but there are better tools for the ...
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1answer
74 views

DDD and edit of Aggregate's descendants

In a DDD approach, suppose I have an Order (this is my aggregate root) and a Line (a descendant of an Order). In both objects I have private setter for properties and a builder that handle creations ...
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97 views

DDD: placement of method whose behavior may be implemented with single database query

Let's say we have Book entity in our library. A requirement says: Librarian may disable 'available' flag to books published before some year. For example, librarian may 'hide' some old books from ...
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1answer
281 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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2answers
192 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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1answer
114 views

If the UI layer depends on the Application layer. Who starts the application/process?

This is related to DDD for a desktop application in c#...with 4 layers ui/application/domain/infrastructure. Actually 3 desktop applications sharing part of the domain and part of the infrastructure. ...
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274 views

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 ...