classConstant.onTrait

Code example

<?php declare(strict_types = 1);

trait MyTrait
{
	public const FOO = 'bar';
}

echo MyTrait::FOO;

Why is it reported?

Accessing a constant directly on a trait name is not allowed. While traits can define constants (since PHP 8.2), those constants can only be accessed through a class that uses the trait, not through the trait itself. PHP does not support accessing trait constants via TraitName::CONSTANT.

In the example above, MyTrait::FOO attempts to access the constant FOO directly on the trait MyTrait.

How to fix it

Access the constant through a class that uses the trait:

 <?php declare(strict_types = 1);

 trait MyTrait
 {
 	public const FOO = 'bar';
 }

 class MyClass
 {
 	use MyTrait;
 }

-echo MyTrait::FOO;
+echo MyClass::FOO;