Software patterns have their roots in architecture. In 1978, Christopher Alexander published a book called ‘A Pattern Language: Towns, Buildings, Construction’ (ISBN-13: 978-0195019193) about the patterns he’d discovered designing buildings. A pattern can be thought of as a tried and tested way of doing something which can be applied in different contexts. Think about how the Observer or Visitor pattern is implemented across languages such as Java, Ruby and JavaScript, where the different language idioms dictate slightly different implementations of the same basic pattern.
Software Patterns became popular with the publishing of the Gang of Four book, “Design patterns: elements of reusable object-oriented software” (ISBN-13: 978-0201633610) in 1994. It contains a number of patterns, most of which every developer should know, even if it’s to know to avoid the likes Singleton. However, these aren’t the only patterns! Indeed, patterns are not created, they are discovered and documented. Whole conferences are dedicated to software patterns (https://www.europlop.net/), where delegates are encouraged to bring their pattern write-ups for appraisal by their peers and the experts.
In 2000 I joined the ACCU, a group for programmers who strive for better software. I was encouraged by another member to write for the group’s magazine, but I didn’t think I’d have anything to contribute that someone better hadn’t already thought of and written about. As I gained experience I found I had quite a lot to write about and to challenge.
In the same way you’d have thought that 23 years after the Gang of Four book most if not all of the software patterns had been discovered and documented. However, it appears not and I was very surprised to find that what I’m calling the “Single CrUD Transaction” pattern, although used by many, doesn’t appear to have been written up anywhere publically. I checked with industry experts and they weren’t aware of it being written-up either.
This is my first software pattern write up and where better to share it for the first time than Norfolk Developers Magazine?
Disadvantages
- Three separate calls to the datastore within a single transaction.