I have an application that I'm trying to build with at least a nominally DDD-type domain model, and am struggling with a certain piece. My entity has some business logic that uses some financial calculations and rate calculations that I currently have inside some domain services, as well as some constant values I'm putting in a value ob...
Hello, I would like to do some exercice and apply DDD to my Domain Model applied to Northwind database. Even if Northwind is an example I imagine that it was done to satisfy some " virtual business" requirements. So the goal is to have a Domain Model that respects DDD and the data is stored in Northiwnd database. Consider this EF persi...
I'm creating some business logic in the application but I'm not sure how or where to encapsulate it, I've used the repository pattern for data access, I've seen some projects that use DDD that have some classes with the "Service" suffix and the "manager" suffix, what are each of this clases suppose to take care of in DDD? ...
This is for using in Safari, though it could probably be used on Firefox as well. In Chrome you have to add a plugin anyway (which generally allow for custom CSS per domain), and Opera already allows this to be done without needing any CSS. But while it's for customizing on the client-side, it's also a pure CSS question. So I'm using no ...
If Book aggregates Chapter which in turn aggregates Page, then what should be the aggregate root? One possibility might be: Book is an aggregate root with Chapter as a leaf and Chapter is an aggregate with Page as a leaf. In this scenario, Chapter is a leaf in one aggregate and a root in another. Is this okay? Would it make sense ...
While searching the web, I came across a list of rules from Eric Evans' book that should be enforced for aggregates: The root Entity has global identity and is ultimately responsible for checking invariants Root Entities have global identity. Entities inside the boundary have local identity, unique only within the Aggregate. Nothi...
I've always developed code in a SOA type of way. This year I've been trying to do more DDD but I keep getting the feeling that I'm not getting it. At work our systems are load balanced and designed not to have state. The architecture is: Website ===Physical Layer== Main Service ==Physical Layer== Server 1/Service 2/Service 3/Servi...
I've seen a lot of codes use a service-dao pattern , I don't know the origin of this pattern . It force the front layer call service , then delegates some of the service task to dao. I want to ask : Does DAO layer do purely data access related task ? What about things like exception encapsulation? Is there any other pattern can be ...
Hello, I have plain POCO's here and as INotifyPropertyChanged is a Interface for the View's need its implemented in the ViewModel not the Model. Now I want to show validation errors in the View beside every textbox the user typed in data. I do not want to implemented the IDataErrorInfo interface in my Models because lets assume I am n...
How does one implement lists such as a list of months in the year, or a list of years in DDD? Where does the logic go, inside value objects, a service, is it part of the domain layer? ...
I am design and EMR. I have determined the central object to the domain is the Patient. The patient must have the following a Doctor and Medical Records. Medical Records is a grouping term refering to the collective of Encounters, Labs, XRays, Prescriptions.... I am new to DDD and I am having trouble with a couple of concepts and my...
I am working on a solution that used DDD for architecture. I have a property in my ViewModel which points to a ValueObject, the view model also implements INotifyPropertyChanged interface. The value of the ValueObject will change as a user enters data on the front end. The problem I am running into is the value object is suppose to be...
Is anyone using the techniques from Domain Driven Design? I've recently read the Eric Evans book of the same name (well, most of it!) and would be interested to hear from anyone who's implemented all/some of it in a project (particularly in C#/C++) I've kept this question open ended as I'd like to see as many comments as possible, but I...
I'm wondering - what i should keep in mind when trying to apply domain driven design on CMS app that has quite complex business logic? Aren't those beasts mutually exclusive? Here's article to show what i mean. ...
What do you do if you need to generate a read-only list of data on a page and that data would naturally come from several, potentially 5 or more different repositories? We're using DDD and have been forcing access to our database through repositories, but there is a scenario that has come up that doesn't seem to fit DDD and we're trying...
In Evans DDD book he speaks of segregating concepts in the domain with "modules". The term "module" can translate to a number of different things in software development, both conceptual and concrete, so I'm wondering how would this concept of DDD modules be expressed in a C#.NET system and if there is any direct correlation to other use...
In our e-commerce application, we have different kinds of products having different kinds of attributes, e.g., a shoe has different selling features than an edible cake. Our e-commerce site allows you to "build" your own products, selecting various attributes and values (like pink frosting on a cup cake which adds $.25 to the cost). Ou...
Hi, as a Mac outsider it seems that two popular programming languages on the Mac appear to be Objective C and Ruby. From what I understand the main API Cocoa seems to be written in and optimized for Objective C, but it is also possible to use Ruby for that. Are there different areas where each language is ideal, for example, I could im...
Apologies for very general question. I repeatedly find that establishing user requirements is one of the hardest parts of my job. This is for several reasons, for example, lack of shared technical vocabulary, incomplete understanding of domain on my part, inability of user to 'imagine' completed UI / product, etc etc. Since this appears...
I just wrote a long (and messy) blogpost about my view on domain-driven design at present day, with frameworks like spring and hibernate massively in use. I'd ask you to spot any problems with my views on the matter - why this won't work, why it isn't giving the benefits of DDD, why it is not a good idea in general. The blogpost is he...