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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12k 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 ...
0
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1answer
22 views

Bounded contexts should contain just domain code?

In Domain-Driven Design there's the idea of bounded context which is basically a way to stablish a boundary within which a certain model is valid as far as I understood. I've found this idea very ...
3
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1answer
337 views

Separation of concerns between repository and service in DDD with complex entities

This probably seems as an example of opinion-based question, but I'm actually looking for rationale on how to decide correctly, I believe there is a correct solution that can be backed by solid ...
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4answers
132 views

Handling DomainExceptions using REST endpoint

Suppose I'm doing some DDD. Now, I have a microservice reflecting a bounded context/a part of a bounded context. Now, suppose there is a REST endpoint: '/somedomainmodel/someaction' My API user is ...
3
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0answers
53 views

Which is the preferable design for my Gateway?

I'm writing a Gateway class that extracts information from a HTML document. One of the responsibilities of the class is to traverse a table in the document and extract data from its rows. I'm trying ...
1
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1answer
79 views

Domain driven design with eventual consistency

My domain aggregate is struggling with simple business logic so I feel like I have modeled it incorrectly. The architecture I have right now uses domain driven design with event sourcing. The domain ...
1
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3answers
58 views

How to reuse domain model logic in services?

I am trying to avoid anemic domain models as it's said to be an anti-pattern. But doing so leaves my services to duplicate some of the logic. class User { public $status; public function ...
2
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1answer
78 views

Integration between services in a SOA

Assume we have a Bounded Context for Inventory (InventoryBC) and another one for Shipments (ShipmentsBC). These 2 BCs need to communicate together. They are hosted on 2 different services on different ...
2
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0answers
31 views

How do you use Domain Events without obfuscating the control flow? [duplicate]

When we have a system which utilizes Domain Events, it can be quite hard to comprehend the whole workflow (sequence of events) of processing a particular command: how many active handlers we have, how ...
1
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1answer
34 views

Maintainability while adding custom findByX methods to DAOs

I'm in the beginning of a project which I want to have the best testability and maintainability possible. To achieve this, I'm reading a lot about concepts in the DDD area, mainly. To get you ...
2
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1answer
47 views

Who should be responsible for syncing a repository?

Given an app, controller, model and repository (which holds representation of model), where should the sync service for the repository live? In my specific implementation, my app/controller are ...
6
votes
1answer
185 views

DDD Architecture in a MVC web application

I am putting together a web application using DDD however am strugleing to put the text book DDD model into a real world MVC application. I currently have these layers: Controllers > ...
0
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0answers
29 views

How to model relationships in scenario where every product can (don't have to) be associated to only one category

This one still occupies my mind. How do you model 1:N relationships. Consider having a category and product (typical e-commerce scenario). Every product can (don't have to) be associated to only one ...
2
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3answers
115 views

Design ideas - validation based on conditions outside of the domain

I am facing a very interesting problem here, and I'd like to see some design ideas from domain driven design perspective. To make it easier to express what I need I have following hypothetical ...
7
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2answers
1k views

Where to validate domain model rules that depend on database content?

I'm working on a system that allows Administrators to define Forms that contain Fields. The defined Forms are then used to enter data to the system. Sometimes the Forms are filled by a human via a ...
25
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6answers
30k views

Difference between a service class and a Helper class [closed]

I would like to know what differentiates a Service class from a utility class or a helper class? A class only with underlying methods calls the dao's is a service? Doesn't the usage of Helper ...
2
votes
1answer
222 views

DDD Validation best practice: entity containing data dosen't have the context to validate before data is set. Where should set function be?

I am pretty new to DDD, so bear with me. I have a Chat room and people in the Chat room. The people in the chat room need to propose a date they would like a webinar to be on. we have a bussiness ...
5
votes
2answers
87 views

Where should business logic go in a layered architecture?

First of all, i'm not talking about validation in the sense of the nullability or length of a field like in this and this questions where we can use isValid() methods in business classes or an ...
1
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2answers
68 views

Models, types, different views and meta data

We have a software which purpose is to be used to help users build their own applications. It has to be very loose coupled with the infrastructure: for example, I can imagine users running it on MySQL ...
1
vote
3answers
348 views

Repository matrix pattern?

I'm trying really hard to refactor some of my legacy code in the project using best practices and design patterns + DDD so I'd love some feedback on an issue I'm currently having. Let's assume that I ...
1
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0answers
34 views

Loading Aggregate Root from Database with Validations

Here is a similar question Where to validate domain model rules that depend on database content? I am asking this new question because I have more descriptions and I don't want to change the ...
4
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1answer
248 views

What and how much domain code should be put in an F# module

According to recommendations given here, F# modules should correspond to DDD bounded contexts, i.e. subdivisions of a business domain. The bounded context I'm working on right now has 2 aggregates ...
3
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3answers
176 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 ...
3
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1answer
788 views

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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2answers
359 views

How does a search functionality fit in DDD with CQRS?

In Vaughn Vernon's book Implementing domain driven design and the accompanying sample application I found that he implemented a CQRS approach to the iddd_collaboration bounded context. He presents ...
4
votes
2answers
212 views

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 ...
3
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1answer
171 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
401 views

What is the best way to create DTOs from entities and update entities from DTOs in a layered architecture?

Option 1: At first I would make a call to my service layer, which served as an API for my core domain, to get a domain object or a list of domain objects and then pass them into the assembler which ...
0
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0answers
55 views

A layer of abstraction too far?

Using an enterprise service bus, a message translator pulls a message off the queue ready to be consumed by a service. The translator picks up the message in a canonical data model (CDM) form and ...
0
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0answers
35 views

DDD Request Validation Handling

I stuck somewhere that I can't find a solution! There are plenty of validation questions here, but as far as I see, most of them were asking about entity validation. But what about request validation? ...
3
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2answers
273 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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0answers
41 views

DDD: Put logic in service or aggregate root?

Let's say we are building a document management system. One project has many documents. I decide to make projects as aggregate root. If the logic to add one document into project is complicated, I ...
4
votes
1answer
70 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 ...
0
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2answers
148 views

Object Oriented Analysis and Design and DDD together

I fear this question seems to broad, so I'll try to explain what I mean with some detail. I couldn't, however, find a way to divide it into other questions. If that's really the case, I gladly accept ...
3
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1answer
259 views

Domain Driven Design - designing Aggregate Roots

Imagine you're designing an application for organizing Workshops. Workshop itself is quite complicated - it acts as a state machine with multiple possible states and transitions between them. We're ...
2
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2answers
189 views

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) ...
2
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2answers
710 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 ...
14
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2answers
419 views

Conceptual mismatch between DDD Application Services and REST API

I'm trying to design an application that has a complex business domain and a requirement to support a REST API (not strictly REST, but resource-oriented). I have some trouble coming up with a way to ...
1
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2answers
106 views

DDD using an ORM and a Active Directory Server for Persistence

With Domain Driven Design one would model out the domain. One would then use an ORM of some sort to take care of the persistence. Say you have a Product entity which has a Name, SKU and an Owner. This ...
0
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0answers
26 views

Controlled access to list of entities vs get/set access in domain model

When designing a domain, either way of following approaches can be used to access list of child entities inside a parent entity. 1. Get/Set Following approach is straight forward and simple to ...
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votes
1answer
60 views

DDD - map or object

What is correct by DDD - should I create map of two objects eg Map or should i use more meaningfull object that will contain this pair MoreMeaningfullName{Obj1, Obj2} ? If using first approach, I ...
0
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2answers
134 views

How to use DDD to solve a common address situation?

This is a simple example to show a situation that I find hard to solve with DDD. Consider this: - A property (e.g. a house) has an Address. - An address can be complete or partial (country only; ...
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2answers
317 views

taxonomy of software project resourcing models

I would like to understand the impact of different resourcing models for software projects. First, I would like to identify the different resourcing approaches that are used to resource software ...
1
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1answer
272 views

Doubts about architectural pattern for customizable standard enterprise application [duplicate]

My company needs to build an application to be rolled out for a lot of clients. This software will have many modules and functionalities, but some of these will need specific adjustments for some ...
0
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0answers
21 views

What is the best way to create DTOs from entities and update entities from DTOs in a layered architecture? [duplicate]

Option 1: At first I would make a call to my service layer, which served as an API for my core domain, to get a domain object or a list of domain objects and then pass them into the assembler which ...
3
votes
3answers
151 views

Approach to designing a workflow web app that contains some automation

I have been tasked with creating a web application which will provide end-users with a self help workflow, asking them questions and skipping to another part of the workflow depending upon the ...
4
votes
2answers
257 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 ...
11
votes
2answers
437 views

How do you handle shared concepts in a microservice architecture?

I am researching architectural patterns for an application I'm developing and a microservice approach seems like it would be a good choice but I am not sure how to handle interactions between the ...
0
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1answer
147 views

DDD - Effective Aggregate Design Questions

I just read Effective Aggregate Design, by Vaughn Vernon. Summarizing the takeaway: Model true invariants Design small aggregates Reference other aggregates by identity Use eventual consistency ...
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2answers
182 views

Implementing an anti-corruption layer with domain logic

I'm building an application that compiles a single PDF document from multiple source PDF documents as follows: it takes the first page of each source document, stamps certain information on top of ...