Enum

PHP Enum done right

Easy way to use enumerated values in PHP.

Installation

Please, use composer.

composer require spareparts/enum

Basic usage

/**
 * @method static OPEN
 * @method static CLOSED
 */
class WindowStateEnum extends \SpareParts\Enum\Enum
{
}

// obtain enum value
$state = WindowStateEnum::OPEN();

// assign enum value
$windows->state = WindowStateEnum::CLOSED();

// compare enum values
if ($window->state === WindowStateEnum::OPEN()) {
    ....
}

// use enum to guard method parameters
function changeWindowState(WindowStateEnum $newState) {
    ...
}

How to prepare Enum

1. extend Enum class
2. Annotate enum class with @method annotations describing Enum values

How to use Enum

There are two possible ways to use enum values, with first one being preferred.

1. using static methods with same name as your desired value.

This works with help from magic __callStatic method, meaning you do not have to add any methods manually.

$state = WindowStateEnum::OPEN();

This method is preferred, as it nicely shows its intended value without having to use weakly guarded strings.

Important tip: To have values correctly autocompleted, use @method annotations, like this:

/**
 * @method static OPEN
 * @method static CLOSED
 */
class WindowStateEnum extends \SpareParts\Enum\Enum 
{
}

This way, your IDE should know WindowStateEnum has 2 methods OPEN and CLOSE and correctly hint on their names. In case you are using IDE without support for @method annotations, you can always just add those methods "for real" :)

2. using instance() method with desired value as instance parameter

$state = WindowStateEnum::instance('OPEN');

There is nothing wrong with this approach, but mistakes/typos can be easily made.

Asking enum for unsupported value

In case you ask for value that is not in the enum values, an InvalidEnumValueException exception is thrown.

try {
    $window->setState(WindowStateEnum::FLYING());
} catch (InvalidEnumValueException $e) {
    echo "This is not a correct state for window to be in!";
}

Testing for multiple values

You can check for enum belonging to any of an enum group / set like this:

if ($state->isAnyOf([Window::OPEN(), Window::CLOSED()]));