First, and mainly, SplEnum
is not integrated to PHP, you have to install it separately.
Using an enum instead of class constants provides the following advantages:
- You can type-hint:
function setAction(Action $action) {
- You can enrich the enum with methods (e.g.
format
,parse
, …) - You can extend the enum to add new values (make your enum
final
to prevent it) - You can get a list of all the possible values (see below)
This Enum class is not intended to replace class constants, but only to be used when it makes sense.
use MyCLabs\Enum\Enum;
/**
* Action enum
*/
class Action extends Enum
{
const VIEW = 'view';
const EDIT = 'edit';
}
$action = new Action(Action::VIEW);
// or
$action = Action::VIEW();
As you can see, static methods are automatically implemented to provide quick access to an enum value.
One advantage over using class constants is to be able to type-hint enum values:
function setAction(Action $action) {
// ...
}
__construct()
The constructor checks that the value exist in the enum__toString()
You canecho $myValue
, it will display the enum value (value of the constant)getValue()
Returns the current value of the enumtoArray()
(static) Returns an array of all possible values (constant name in key, constant value in value)
class Action extends Enum
{
const VIEW = 'view';
const EDIT = 'edit';
}
// Static method:
$action = Action::VIEW();
$action = Action::EDIT();
Static method helpers are implemented using __callStatic()
.
If you care about IDE autocompletion, you can either implement the static methods yourself:
class Action extends Enum
{
const VIEW = 'view';
/**
* @return Action
*/
public static function VIEW() {
return new Action(self::VIEW);
}
}
or you can use phpdoc (this is supported in PhpStorm for example):
/**
* @method static Action VIEW()
* @method static Action EDIT()
*/
class Action extends Enum
{
const VIEW = 'view';
const EDIT = 'edit';
}