class

Class

Introduction

The class component provides a set functions to retrieve information about a class.

!> The Class component is not a replacement for PHP Reflection API.

Usage

use Psl;
use Psl\Class;

abstract class Foo {
  public function bar(): void {}
}

Psl\invariant(true === Class\is_abstract(Foo::class), '"Foo" should be abstract.');
Psl\invariant(true === Class\has_method(Foo::class, 'bar'), '"Foo" should have a "bar" method.');
Psl\invariant(false === Class\has_constant(Foo::class, 'QUX'), '"Foo" should not have constant "QUX".');

API

Functions

• [Class\defined(class-string $class_name): bool php]

  Checks if the class with the given name has already been defined.

  This function will return true if a class exists, but has not been loaded yet.

  • [$class_name php]: The name of the class to check.

  use Psl\Class;
  use Psl\Collection;
  
  class Foo {}
  class Bar {}
  
  Class\defined(Foo::class); // true
  Class\defined(Bar::class); // true
  Class\defined(Baz::class); // false
  Class\defined(Collection\Map::class); // false

• [Class\exists(class-string $class_name): bool php]

  Checks if the class with the given name exists.

  If the given class is not defined, this function will attempt to load it.

  If the given class is not defined and cannot be loaded, this function will return false.

  • [$class_name php]: The name of the class to check.

    use Psl\Class;
    use Psl\Collection;
  
    class Foo {}
    class Bar {}
  
    Class\exists(Foo::class); // true
    Class\exists(Bar::class); // true
    Class\exists(Baz::class); // false
    Class\exists(Collection\Map::class); // true

• [Class\has_constant(class-string $class_name, string $constant_name): bool php]

  Checks if the class with the given name has a constant with the given name.

  • [$class_name php]: The name of the class to check.
  • [$constant_name php]: The name of the constant to check.

  If [$class_name php] does not exists, this function will throw [Psl\Exception\InvarientViolationException php].

  use Psl\Class;
  
  class Foo {
    const BAR = 'baz';
  }
  
  Class\has_constant(Foo::class, 'BAR'); // true
  Class\has_constant(Foo::class, 'BAZ'); // false

• [Class\has_method(class-string $class_name, string $method_name): bool php]

  Checks if the class with the given name has a method with the given name.

  • [$class_name php]: The name of the class to check.
  • [$method_name php]: The name of the method to check.

  If [$class_name php] does not exists, this function will throw [Psl\Exception\InvarientViolationException php].

  use Psl\Class;
  
  class Foo {
    public function bar(): void {}
  }
  
  Class\has_method(Foo::class, 'bar'); // true
  Class\has_method(Foo::class, 'baz'); // false

• [Class\is_abstract(class-string $class_name): bool php]

  Checks if the class with the given name is abstract.

  • [$class_name php]: The name of the class to check.

  If [$class_name php] does not exists, this function will throw [Psl\Exception\InvarientViolationException php].

  use Psl\Class;
  
  class Foo {}
  class Bar {}
  abstract class Baz {}
  
  Class\is_abstract(Foo::class); // false
  Class\is_abstract(Bar::class); // false
  Class\is_abstract(Baz::class); // true

• [Class\is_final(class-string $class_name): bool php]

  Checks if the class with the given name is final.

  • [$class_name php]: The name of the class to check.

  If [$class_name php] does not exists, this function will throw [Psl\Exception\InvarientViolationException php].

  use Psl\Class;
  
  class Foo {}
  class Bar {}
  final class Baz {}
  
  Class\is_final(Foo::class); // false
  Class\is_final(Bar::class); // false
  Class\is_final(Baz::class); // true