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Declaring Attribute Classes

While not strictly required it is recommended to create an actual class for every attribute. In the most simple case only an empty class is needed with the #[Attribute] attribute declared that can be imported from the global namespace with a use statement.

<?php

namespace Example;

use Attribute;

#[Attribute]
class MyAttribute
{
}

To restrict the type of declaration an attribute can be assigned to, a bitmask can be passed as the first argument to the #[Attribute] declaration.

<?php

namespace Example;

use Attribute;

#[Attribute(Attribute::TARGET_METHOD | Attribute::TARGET_FUNCTION)]
class MyAttribute
{
}

By default an attribute can only be used once per declaration. If the attribute should be repeatable on declarations it must be specified as part of the bitmask to the #[Attribute] declaration.

<?php

namespace Example;

use Attribute;

#[Attribute(Attribute::TARGET_METHOD | Attribute::TARGET_FUNCTION | Attribute::IS_REPEATABLE)]
class MyAttribute
{
}