PHP Enum implementation inspired from SplEnum

Why?

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.

Declaration

use MyCLabs\Enum\Enum;

/**
 * Action enum
 */
class Action extends Enum
{
    const VIEW = 'view';
    const EDIT = 'edit';

    /**
     * @return Action
     */
    public static function VIEW() {
        return new Action(self::VIEW);
    }

    /**
     * @return Action
     */
    public static function EDIT() {
        return new Action(self::EDIT);
    }
}

Implementing the static methods VIEW() and EDIT() is optional, it only serves as shortcut to new Action(Action::VIEW).

Usage

$action = Action::VIEW();

// or
$action = new Action(Action::VIEW);

One advantage over using class constants is to be able to type-hint enum values:

function setAction(Action $action) {
    // ...
}

Documentation

• __construct() The constructor checks that the value exist in the enum
• __toString() You can echo $myValue, it will display the enum value (value of the constant)
• getValue() Returns the current value of the enum
• toArray() (static) Returns an array of all possible values (constant name in key, constant value in value)