wscore/enum

Enumerated class.

1.0.0 2017-11-10 11:14 UTC

MIT

• Asao

README

Enum and list implementation

Licence

MIT License

Installation

composer require "wscore/enum: ^1.0"

Sample Code

create a EnumList class

The intended way of creating a enumerated class is,

1. define constants,
2. define static $choices array.

as in the example below.

use WScore\Enum\AbstractEnum;

class EnumList extends AbstractEnum
{
    const ENUM = 'enum';
    const VALUE = 'value';
    
    protected static $choices = [
        self::ENUM => 'enumerated',
        self::VALUE => 'value',
    ];
}

The $choices variable defines available values along side with labels (i.e. human readable string).

get enumerated object

static function, enum, returns an instantiated enumerated object, which is EnumInterface

$enum = EnumList::enum(EnumList::ENUM);
(string) $enum; // enum
$enum->label(); // enumerated
$enum->is(EnumList::ENUM); // true

enum list and keys

Use static methods such as, choices(), keys(), or flipped(), to get the list of available enum values and keys, that may be used for validating inputs.

$list = EnumList::choices(); // returns list of keys and labels. 
$keys = EnumList::keys();    // returns keys of enumerated list. 
$flip = EnumList::flipped(); // returns array of key/value flipped.

subset of choices

In some use cases, you may need to restrict the selectable values. For instance, the ActiveList class below, has 3 statuses but may want to restrict to only 2 options for the end-user, as defined in in userChoice.

class ActiveList extends AbstractEnum
{
    const ACTIVE = 'active';
    const CANCEL = 'cancel';
    const HOLD   = 'hold';
    
    protected static $choices = [
        self::ACTIVE => 'activated',
        self::CANCEL => 'canceled',
        self::HOLD   => 'hold-on',
    ];

    /**
     * @return array
     */
    public static function userChoice()
    {
        return [
            self::ACTIVE => 'activated',
            self::CANCEL => 'canceled',
        ];
    }
}

To get the available choices,

$list = ActiveList::userChoice(); 
$keys = ActiveList::keys('userChoice');
$flip = ActiveList::flipped('userChoice');

really restricting use of list

To really limit choices to the subset of the original static::$choices...

use WScore\Enum\AbstractEnum;

class EnumList extends AbstractEnum
{
    const ENUM = 'enum';
    const VALUE = 'value';
    protected static $choices = [
        self::ENUM => 'enumerated',
        self::VALUE => 'value',
    ];

    /**
     * @param string $value
     * @return EnumList
     */
    public static function getUserEnum($value)
    {
        $choices = self::$choices;
        unset($choices[self::VALUE]);
        return new EnumList($value, $choices);
    }
}

then, the following code will throw an \InvalidArgumentException.

$enum = EnumList::getUserEnum(EnumList::VALUE);