A domain model is composed of the objects, behavior, relationships, and attributes that make up the industry that is the focus of development.
0
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1answer
78 views
TDD: How to test domain model
When practicing TDD, how do you test a domain model? If you don't test, how do you account for code coverage? We want to have 100% coverage (or as much as possible), but despite hours of training ...
2
votes
1answer
49 views
MVP / MVC role of the Model (not anemic one) clashes with presenter / controller role (responsibilities in the right place, Model OR Presenter)?
The problem / question
I have been looking at MVP implementation and process to design a good domain model (not anemic). It says that the domain model should have its own behavior and not being a ...
4
votes
3answers
143 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 ...
8
votes
2answers
229 views
Should well-known business ID of an entity be represented with a dedicated type in DDD/OOP?
In practical terms it means using an custom (immutable) class over a string or some other primitive type.
Examples:
Publishing: International Standard Book Number.
Finance: International Securities ...
4
votes
1answer
58 views
Should domain model be intelligent or there must be services, which operate it?
I'm building a web-app for a licensing service. My domain models are Licenses, and they can be of two types at the moment: server and client license. They are almost same, except server license has ...
4
votes
1answer
52 views
Strategy to define domain data used in Integration Tests
In my job we work in a data driven web application and performance is a important business feature. So, queries in the model tier are frequently large
and contain much of the business logic. As a ...
2
votes
2answers
75 views
Authenticate in the Services? Or in an Endpoint that exposes the Services?
When I'm in charge, I typically model services separate from endpoints. For example: Company.Project.Domain.dll has all of the logic required to complete the services for that domain. In order to ...
0
votes
0answers
67 views
JavaFX Synchronize DataModel with Business Domain
I am currently working on a javaFX (first time) frontend for one of our applications. For this i'm using a simple MVC pattern where my model classes use properties so that i can directly bind them to ...
0
votes
0answers
36 views
Dealing with stale data / currency issues when lazy loading related entities
Imagine I have two associated domain entities with a one-to-many relationship. Here is an example with Customer and Order classes:
public class Customer
{
public int ID { get; internal set; }
...
3
votes
2answers
183 views
Domain object model: query by id vs object
Let assume I have two simple model classes: Product and Brand
It is obvious I have a query method in Product class like this
Product product = Product.findById(123);
What if, I want to query ...
2
votes
5answers
202 views
Should I use inheritance to differentiate objects even if they have the same fields?
Consider this simple class that models a real world mobile device:
/// <summary>
/// Model that represents a device.
/// </summary>
public class Device
{
public DateTime ...
4
votes
3answers
104 views
How do I model this relationship so that it is valid by construction?
Imagine a device class that represents a physical real world mobile device, with fields like Enabled, Platform, Model IMEI, etc. Then, an operation class, which is something that needs to be done to a ...
0
votes
2answers
140 views
Handling Business Logic/Validation Race Conditions
I'm working on a Training Enrollment web application with the following (simplified) features:
Maintenance (Add, Edit, Deactivation) of Trainings
Student sign-up
Student enrollment to Active ...
1
vote
2answers
120 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 ...
1
vote
2answers
140 views
How can I create a model to efficiently answer the question of - where to place my db-interaction code I am about to write?
I am seeking the right model for storing and retrieving data, when working with any specific class, while keeping in mind the bigger picture.
Details:
I have some SQL code in (one) of my classes and ...
2
votes
3answers
131 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 ...
1
vote
2answers
190 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 ...
2
votes
2answers
65 views
Domain Modeling - Offerings vs. Usages
I have a question about an issue I always seem to run into when building a domain model. The issue comes up whenever a domain object is used in what I am calling an "offering" scenario and in a ...
0
votes
2answers
177 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; ...
2
votes
2answers
110 views
Should ids be mapped to the implementation type
This is a question of model design, and hopefully some architecture nerds have strong opinions on this. I've been developing one that I will post in an answer.
Typically, in every codebase I've ever ...
0
votes
1answer
176 views
Class Table Inheritance: do child tables need a primary key?
I'm using the Class Table Inheritance architecture with my application and have read Fowler. When mapping my database tables to classes in code, I've realized I have no need for an "ID" property on ...
0
votes
1answer
459 views
Clean architecture: should users go in the use case layer or the domain layer?
I recently read this article about Clean Architecture, as I'm trying to get out of some usual OO habits (interface design everywhere, but what does it do???), and program something that describes what ...
3
votes
1answer
54 views
Dealing with Users and User-Owned Data in an API
I have a question about the way I am architecting an API.
Structure
My API structure so far is like so (there is about 10 classes total, but many are similar, so I've reduced to these classes, and ...
1
vote
1answer
217 views
Help Improve DB model/strategy, for use in refactoring SQL-ridden legacy code
Question:
Which design pattern do I use to help me refactor legacy SQL code into separate classes?
Goal
Bring in concepts of data separation and database separation and also latest modern ...
1
vote
1answer
45 views
Domain models with properties not always set
I don't know if to have domain models with properties that not always are set, it's a some kind of code smell or design error. I put an example:
I have an app that lets read internet magazines using ...
2
votes
2answers
131 views
Domain/Model objects attributes good practices
Simple question: Should model/domain objects only include attributes that are meant to be persisted in a database or serialized to any other specific format?
My understanding of a domain/model object ...
2
votes
1answer
114 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 ...
5
votes
3answers
365 views
Model relationships with DDD (or with sense)?
Here is a simplified requirement:
User creates a Question with multiple Answers. Question must have at least one Answer.
Clarification: think Question and Answer as in a test: there is one ...
6
votes
3answers
435 views
In domain driven design, how do I convert a database table with a primary key into a Value Object?
Lets suppose there's a database schema defined like this:
Person.mail_address_key ----- Address.address_key
Person.billing_address_key ----- Address.address_key
A Person has a mailing address and a ...
1
vote
1answer
142 views
DB modeling for staffing demand and supply
TL;DR - I'm looking for guidance with my database design. I am concerned that my existing design is inefficient and won't be able to handle large numbers of employees.
This is going to be long, so ...
0
votes
2answers
219 views
Entity design for a blackjack game - should I make Card an entity?
I am creating a simple blackjack game backed by database
In my Card is
public class Card{
private Face face;
private Suit suit;
//setters.. getters
}
where face and suit are enums
I have an ...
1
vote
4answers
208 views
Domain model associations that do not required the behaviour of the associated object. How to model?
I've been struggling with this question for a while.
I'm specifically thinking within the object orientated domain model.
Let's say I have two entities. A supplier and a customer. There is a ...
0
votes
1answer
75 views
Allow entities owned by one user to be referenced by other users' entities
I am working on an Asp.NET MVC web application.
I have the following (simplified) entities:
public class Course
{
public int Id { get; set; }
public string Name { get; set; }
public ...
0
votes
1answer
254 views
How do I keep my classes in MVC from becoming bloated?
I'm not sure how I should have worded the question.
If I have a Student and Classes database, and I have queries that involve both. Where do I put my queries? In one case, someone wants student ...
1
vote
1answer
377 views
Domain model for a notification system
I'm trying to build a modular notification service in a ASP.NET MVC web application. The application generates notifications and the service is responsible for delivering the notifications to the ...
1
vote
1answer
130 views
Domain-specific Interfaces
Are there any real benefits of using interfaces over abstract classes in a domain model? Does anyone have any experience using interfaces in a domain model in a real project?
From a technical ...
3
votes
2answers
313 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 ...
2
votes
3answers
386 views
“Cross-cutting” domain in DDD
I've recently started studying Domain Driven Design and so far it looks like it will help tremendously with my team's current project. I'm running into a bit of a problem though actually determining ...
0
votes
2answers
779 views
DTO - service layer - statelessness best practices interfering with each other
I am designing a REST API coupled with a service layer that takes DTOs as input and produces them as output. This works fine for most service calls where the DTO is used to access an underlying ...
0
votes
1answer
198 views
Technical example of modeling a domain with OOD?
Considering favoring composition over inheritance and looking at various design patterns there are multiple approaches to modeling a domain.
Say you have some Entities which are very similar in some ...
1
vote
1answer
484 views
How do you handle domain logic that spans multiple model objects in an ORM?
So I know that business logic should be placed in the model. But using an ORM it is not as clear where I should place code that handles multiple objects.
E.g. let's say we have a Customer model which ...
3
votes
1answer
281 views
How to present domain model exceptions thrown through validation
In domain model of my web application I've an entity Foo which can be created only by a pojo FooBean: Foo.newInstance(FooBean fooBean) (Might have been better a Builder-pattern.)
In the factory ...
2
votes
3answers
212 views
Should data models know where / how they're stored?
I have some classes that represent, for the most part, data that's deserialized from XML. They also have some behavior in them, because I don't want to suffer from an anemic domain model. These domain ...
2
votes
3answers
300 views
Should POCO domain classes contain collections?
The question title is not good, but I couldn't think of a way to word it better.
I am used to develop using POCO classes in my projects, that is, domain objects contain absolutely no logic, only ...
1
vote
0answers
38 views
Domain security involving domain logic
Together with my application's domain logic I am trying to outline the security model. I am stuck with a requirement that prevents me from considering security just a cross-cutting concern over my ...
1
vote
1answer
300 views
Cascading deletes from an aggregate root through out the entire aggregate doesn't make sense
Based on the same example for this question.
Within the Pro ASP.Net MVC 4 by Adam Freeman, there is a discussion on aggregates and aggregate roots with a simple auction system. There are members who ...
1
vote
1answer
350 views
DDD - Business rule that depends on a service
I got confused about if a domain is required to access an external service in some state of it's life cycle.
The business rule is this :
If an Employee is accepting a JobSeeker's JobApplication, ...
2
votes
2answers
198 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 ...
2
votes
2answers
762 views
ID properties on Domain objects in DDD
In my domain I have an Account object.
e.g.
class Account
{
public string Number;
public string SortCode;
}
Within the context of DDD, should this account object have an ID property? The ...
2
votes
0answers
135 views
Rails: get data about a model collection, with new model or method?
I have a model Product with attributes sales and views. I need to get sales/views count of all the products. Is more correct to implement this as a method and have a call like Product.all.sales or ...
