Tag Archive 'design'

If you happen to create your own annotations, for instance to use with Java 6 Pluggable Annotation Processors, here are some patterns that I collected over time. Nothing new, nothing fancy, just putting everything into one place, with some proposed names.

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.

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 [...]

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 [...]

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 [...]

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 [...]

Many concepts look obvious because they are used often, not because they are really simple.
Small quantities that we encounter all the time in most projects, such as date, time, price, quantity of items, a min and a max… hardly are a subject of interest from developers “as it is obvious that we can represent them [...]

For tools to be aware of patterns, the patterns must be formalized, at least partially. At this point I must quote Gregor Hohpe to clarify my thoughts, as I strongly agree with his skipticism:
Typically, when people ask me about “codifying” or “toolifying” patterns my first reaction is one of skepticism. Patterns are meant to be [...]

Over time, patterns have appeared on many different topics, not all related to programming. Here is a list of patterns and pointers to other lists of patterns, to illustrate two things:

Knowledge and experience in general can be packaged into patterns, often using the pattern form. Patterns are convenient for reuse, in any domain.
There are already [...]

In my very first job, I  was doing R&D, working on a map-matching algorithm. The goal of this algorithm was to pinpoint a moving car on a vector map, based on the data from various sensors, including a GPS, an electronic compass and the car odometer. Such algorithm was essential for the business of the [...]