Look at the following code:
<?php
enum Types:string {
case A = 'a';
case B = 'b';
}
#[Attribute(Attribute::TARGET_CLASS)]
class MyAttribute {
public function __construct(public readonly array $mapping)
{
}
}
#[MyAttribute(mapping: [Types::A->value => ''])]
class Entity {
}
It has error Constant expression contains invalid operations. I would like to use Enum value in my attribute for defining configuration. Seem like it is bug in php. Should it be reported or something?
The problem is that when we call Types::A->value it actually creates instance of an enum, which is not a constant value. To solve this problem define a constant and reference it.
<?php
abstract class Type {
public const A = 'a';
public const B = 'b';
}
enum TypesEnum:string {
case A = Type::A;
case B = Type::B;
}
#[Attribute(Attribute::TARGET_CLASS)]
class MyAttribute {
public function __construct(public readonly array $mapping)
{
}
}
#[MyAttribute(mapping: [Type::A => ''])]
class Entity {
}
Watch out for this issue in php