Freek Lijten has written up a new post to his blog about a set of development principles that have been getting more press in the PHP community lately - SOLID. In his post he starts with a look at the "S" in the set - "Single Responsibility".

The single responsibility principle isn't all that hard to explain. It states that an object should do one thing, and one thing only. [...] A responsibility is a reason to change, and a class should only have one of those. Now all of this may sound abstract and since the objective of this series is to avoid just that we'll just dive into the why now.

He includes some sample code to illustrate, going with an active record implementation, some of the problems that come with a typical setup including issues with unit testing, bad practice of using the data store directly, etc. He shows a refactored code example that splits out the functionality previously all in the one class ("Bike") into three different ones - one is the normal Bike object, another compares the Bikes and the third works with the data store to handle the CRUD for the objects.

Cal Evans has a suggestion for all of the developers out there not happy with decisions being made at their workplace (or in the contracts they work with) - man up!

Look, it's easy. As developers, we see people we don't respect making decisions we don't agree with. I know how difficult this position is because like every other developer in the world, I've been in this position. However, unlike a lot of developers I've talked to in recent years, I don't see "digging my heals in" or whining as alternatives.

He suggests one of two alternatives to the situation - either deal with things head-on and get onboard with the decision or jump ship and find something else that suits you better. Sometimes this is a bit easier than others (terminating contracts versus leaving a full-time job), but if you're really that upset with it, it's probably not going to get any better.

talk to a lot of people about how to build teams and the cornerstone of any good team is respect. Management has to respect developers and I firmly believe that. However, you as a developers, have to respect management as well. It is a two way street.

DevShed is starting off a new series today with this first article talking about how to introduce the "chain of responsibility" method in how you use your objects.

In this three-part series, I'll show you how to create a chain of responsibility across different classes, which hopefully will give you a better understanding of how this schema can be implemented with PHP.

Since it's just the first part in the esries, they start with the whys and hows of the chain of command process before getting on with the actual code. For the foundation, they create some subclasses that will make the parts of the chain. Next up is combining them and, finally, making the "master class" to combine the links of the chain together. They use a "DataServer" example to work with local files.