Enum implementation for PHP

v1.3.0 2020-03-05 14:54 UTC

This package is auto-updated.

Last update: 2020-11-05 16:52:31 UTC


README

Scrutinizer Code Quality Code Coverage Build Status Total Downloads Latest Stable Version License

Enum

Enum implementation for PHP

Installing

Use composer to pull this package in.

With Composer

$ composer require joskolenberg/enum

Usage

Setting up an enum

An enum can be created by extending the JosKolenberg\Enum\Enum class.

use JosKolenberg\Enum\Enum;

class UserType extends Enum {}

This created class acts as the repository via static methods as well as the enum itself.

There are two abstract methods which have to be implemented. Use the seed method to populate the class with Enums, and tell the class which attribute identifies the enums by returning the name of this attribute in the identifierAttribute method.

An example implementation would be:

use JosKolenberg\Enum\Enum;

class UserType extends Enum
{

    protected $id;

    protected $name;

    public function __construct($id, $name)
    {
        $this->id = $id;
        $this->name = $name;
    }

    /**
     * Seed the class with Enum instances
     *
     * @return array
     */
    protected static function seed()
    {
        return [
            new static('dev', 'Developer'),
            new static('admin', 'Administrator'),
            new static('user', 'User'),
        ];
    }

    /**
     * Return the name of the attribute which stores the identifier
     *
     * @return string
     */
    protected function identifierAttribute()
    {
        return 'id';
    }
}

Next, the class can be designed like way you would any other.

Repository

The class offers the following static "repository-like" methods:

  • get() return the enum with the given identifier.
  • random() return a random identifier (e.g. for seeding).
  • collection() return an Illuminate\Support\Collection containing all enums.
  • identifiers() return an Illuminate\Support\Collection containing only the identifiers for the enums.
  • exists() tell if an enum with the given identifier exists.

Enums are also available using a magic method with the same name as the identifier. e.g. UserType::get('dev') equals UserType::dev()

Enum

The enum itself has the following methods:

  • identifier() return the identifier value (e.g. 'dev' or 'admin' in the previous example) of this instance.
  • equals(Enum $enum) check if the given enum matches the current.

All defined attributes are by default available as read-only:

  • $value = $userType->value passes.
  • $userType->value = 'changed' fails.

Custom Classes

If different enums of the same type should have different behaviour you can extend the base enum to more specific ones.

class UserType extends Enum
{

    protected $id;
    protected $name;

    protected static function seed()
    {
        return [
            new UserTypeDev(),
            new UserTypeAdmin(),
        ];
    }

    protected function identifierAttribute()
    {
        return 'id';
    }
}

class UserTypeDev extends UserType{
    
    public function __construct()
    {
        $this->id = 'dev';
        $this->name = 'Developer';
    }

    public function whatCanYouDo()
    {
        return 'I can code';
    }
}

class UserTypeAdmin extends UserType{
    
    public function __construct()
    {
        $this->id = 'admin';
        $this->name = 'Administrator';
    }

    public function whatCanYouDo()
    {
        return 'I can do some important stuff';
    }
}

If you wish to extend the functionality of the collection, you can assign your own custom collection to your enum using the static newCollection method.

    protected static function newCollection(array $enums = [])
    {
        return new MyCustomEnumCollection($enums);
    }

Pre-defined Enums

Because enums are usually no more than an identifier and maybe a display value, two pre-defined enums are available to extend.

Extend EnumWithId for an enum with only an id attribute:

class UserStatus extends \JosKolenberg\Enum\EnumWithId
{
    protected static function seed()
    {
        return [
            new static('new'),
            new static('active'),
            new static('deleted'),
        ];
    }
}

Or extend EnumWithIdAndName for an enum with an id and name attribute:

class ExtendedUserType extends \JosKolenberg\Enum\EnumWithIdAndName
{
    protected static function seed()
    {
        return [
            new static('dev', 'Developer'),
            new static('admin', 'Administrator'),
            new static('user', 'User'),
        ];
    }
}

Or create your own baseclass if you wish for different attributes on all of your enums.

Happy coding!

Jos Kolenberg joskolenberg@gmail.com