Upgrading Older Versions

From v3 To v4

PHP 8.0+

First, Enum v4 requires PHP 8.0 or later to run. Earlier PHP versions are not supported.

Strict Type Checking

The most important difference between 4.0 and 3.X versions is that All the values of the enums are now strictly typed.

In earlier versions you could do this:

class OrderStatus extends \Konekt\Enum\Enum {
    public const ORDERED = 1;
    public const SHIPPED = 2;
    public const CANCELLED = -1;

$shipped = new OrderStatus('1'); // Note that a string was passed;

Beginning with v4.0, this will throw an UnexpectedValueException. It means that you always need to pass the value of the original type to the constructor.

The same applies to the create() method:

// In v4:
// throws an UnexpectedValueException

Handling of Null Values

Null Is No Longer Zero

As a consequence of strict type checking, you can distinguish between 0 and null values:

class TriState extends \Konekt\Enum\Enum {
    public const __DEFAULT = self::ANY;
    public const ANY = NULL;
    public const CHECKED = 1;
    public const UNCHECKED = 0;

In Enum v3 and earlier versions this was not working properly, TriState::create(0) resulted in Tristate::ANY() and not Tristate::UNCHECKED()

Null As Non-Default

In Enum v3 and earlier, if you created an Enum with a null value, it only worked well if it was either the default or if there was no other default.

Beginning with v4, you can define enums with null values AND specify another default:

class MatchingPattern extends \Konekt\Enum\Enum {
    public const __DEFAULT = self::INCLUDE;
    public const IGNORE = null;
    public const INCLUDE = 'include';
    public const EXCLUDE = 'exclude';

Return, Argument and Attribute Types

Besides type strictness, the entire base class has been updated to use type definitions on all methods, arguments and class members.

As a consequence, you need to specify the corresponding types in your enum classes on any property or method that you have overwritten from the base Enum class.

As an example if you're using fallback enums, then you have to add the bool type specifier to your enum class:

class YourEnum extends \Konekt\Enum\Enum {
    // This worked with v2.3 and 3.x:
    protected static $unknownValuesFallbackToDefault = true;
    // In v4, you must specify the type (bool):
    protected static bool $unknownValuesFallbackToDefault = true;

Type Compatibility Checklist

Check if your enums have any of the following properties/methods:

  • [ ] $unknownValuesFallbackToDefault: add the bool type: protected static bool $unknownValuesFallbackToDefault
  • [ ] choices() method: add return type : array
  • [ ] toArray() method: add return type : array

When doing comparison with equals() or notEquals() make sure you pass an enum instance and not a string or other scalar. Due to the lack of type safety in v3 and before this did not give an error:

$red = Color::RED()
//=> false

As you see this still gave false, so it didn't actually work even earlier, but the error got "swallowed". Doing the same with v4 raises a type error:

TypeError: Konekt\Enum\Enum::equals(): Argument #1 ($object) must be of type object, string given

To fix it do this instead:

// or
// or
// or

From v2 To v3

The most important difference between 3.0 and 2.X versions:

The __default const is now uppercase __DEFAULT in order to fully comply with the PSR-1 standard.

This is a BC so if you want to use version 3.0, you have to check your codebase for enums that have __default constants defined and rename them to __DEFAULT.

If you don't want to do this, you can safely keep using the 2.x versions.

From v1 To v2

Renamed Methods

  • getValue() -> value()
  • getDisplayText() -> label()
  • hasValue() -> has()
  • hasKey() -> hasConst()

Consistent Naming

In order to be more straightforward, the following naming changes have been done:

  • 'Display text' has become 'label'
  • 'Key' has become 'const'
  • 'Values' is intact

Removed Features

  • strict comparison (===) has been removed (is always ==)
  • toArray() never returns the '__default' key.

Null Values Must Be Explicit

It's not possible to have enums without values any more.

If you want to have a null value it is possible by explicitly setting one of the values to NULL:

class Progress extends \Konekt\Enum\Enum
    const UNKNOWN     = null;
    const INITIALIZED = 1;
    const COMPLETED   = 2;

Then you can have a null value:

$unknown = Progress::create();
// output: NULL

New Static Methods

  • values(): returns all the values as an array.
  • labels(): returns the labels (with fallback to values if no label defined). Elements are always strings.
  • consts(): returns the const names in an array.
  • create($value): factory method for creating an instance with value
  • reset(): Clears static class metadata
  • defaultValue(): static method to return the value of the class (__default const or null if unset)

Next: Creating Enums »