Domain-Driven Design encourages to analyse the domain deeply in a process called Supple Design. In his book (the blue book) and in his talks Eric Evans gives some examples of this process, and in this blog in several parts I will suggest some sources of inspirations and some recommendations drawn from my practice in order to help about this process.
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Tags: analysis, ddd, design, domain, intent, maths, pattern, Programming, theory, tree
Posted in Patterns, Programming, ddd • 1 Comment »
Reuse is often assumed to mean code reuse, but there are many other kinds of reuse. You can also reuse ideas, and even reuse the process of applying ideas.
Why reuse?
We want to reuse prior work or knowledge for several reasons:
It is easier to reuse than to redo the effort that would lead to the same [...]
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This anti-pattern is about Using String instances all the time instead of more powerful objects. This is a special case of primitive obsession.
Examples
Here are some flavours of this anti-pattern:
String as keys in a Map: I have seen calls to toString() on objects just to use their String representation as a key in a Map: [...]
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Tags: antipattern, java, oo, Programming, valueobject
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Consider a domain, for example an online bookshop project that we call BuyCheapBooks. The Ubiquitous Language for this domain would talk about Book, Category, Popularity, ShoppingCart etc.
Business Domains
From scratch, coding this domain can be quite fast, and we can play with the fully unit-tested domain layer quickly. However if we want to ship, we will [...]
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Tags: crosscuttingconcern, ddd, design, domain, Programming
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Small details matter because you deal with them often. Any enhancement you make thus yields a benefit often, hence a bigger overall benefit. In other words: invest small care, get big return. This is an irresistible proposal!
Examples of small design-level details that I care about because I have experienced great payback from them:
Using Value Objects [...]
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Tags: craftsman, ddd, design, domain, human, methodology, Programming, trick
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Deciding where and how to place the annotations is not innocent. The last thing we want is to create extra maintenance effort because of the annotations. In other words, we want annotations that are stable, or that change for the same reasons and at the same time than the elements they annotate. This article suggests [...]
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Tags: annotation, aop, architecture, c#, classdiagram, crosscuttingconcern, dependencies, design, domain, intent, intrinsic, java, location, pattern, Programming, stereotype, uml, use case
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The concept of degrees of freedom looks so relevant to software development that I am wondering why it is not considered more often. Fortunately Michael L. Perry dedicates a full section of his blog to that concept. In this post I will quote a lot, please consider that as a sign of enthusiasm.
A common concept [...]
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Tags: analysis, ddd, design, dof, domain, education, maths, methodology, problem, Programming, solution
Posted in Programming • 1 Comment »
In software development, a key principle is to deliberately look for constraints and restrictions.
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