One rule to write a perfect Trait in PHP

Multi-trait flower Hokkaido :)

To begin, what are PHP Traits?

A PHP Trait is simply a lot of methods that you want include within another class.

A PHP Trait it’s a little bit like an abstract class but a Trait cannot be instantiated!

The “use” keyword must be declared in the top of your class to use the Trait.

For example (PHP 7 syntaxe):

trait Hello
{
    public function hello() : string
    {
        return 'Hello';
    }
}
class Say
{
    use Hello;
}
(new Say)->hello(); // Hello

The important consideration

• A Trait is not a class!
• A Trait is not an abstract class!
• A Trait is not an interface!

In closing,

The only rule to write a perfect Trait in PHP is just to use it like a Mixin, without external dependencies! A Trait is philosophically self-sufficient!

A Trait can be used in any classes, abstract or not.