PHP instanceof for traits

Question

What is the proper way to check if a class uses a certain trait?

Answer 1

While nothing stops you from using methods to determine if a class uses a trait, the recommended approach is to pair traits with interfaces. So you'd have:

class Foo implements MyInterface {     use MyTrait; } 

Where MyTrait is an implementation of MyInterface.

Then you check for the interface instead of traits like so:

if ($foo instanceof MyInterface) {     ... } 

And you can also type hint, which you can't do with traits:

function bar(MyInterface $foo) {     ... } 

In case you absolutely need to know whether a class is using a certain trait or implementation, you can just add another method to the interface, which returns a different value based on the implementation.