Aide for Enums

A collection of traits and classes to improve handling PHP's Enum.

Caution

Sub-split of Aide for Enum helpers.
⚠️ this is a sub-split, for pull requests and issues, visit: https://github.com/bakame-php/aide

Installation

Composer

composer require bakame-php/aide-enums

System Requirements

You need:

• PHP >= 8.1 but the latest stable version of PHP is recommended

Usage

Traits

Factory

Enable creating Pure or Backed Enum based on their name. The trait adds two (2) new static methods, tryFromName and fromName and re-introduce the tryFrom and from method on pure Enums. Once added to your Enum you can do the following:

<?ph

HttpMethod::fromName('Get') === HttpMethod::Get;
HttpMethod::tryFromName('Get') === HttpMethod::Get;
HttpMethod::tryFromName('Unknown'); // returns null
HttpMethod::tryFrom('Put') === HttpMethod::Put
HttpMethod::From('Unknown'); //throw a ValueError

You need the Bakame\Aide\Enum\Factory trait to expose the new API.

<?php

use Bakame\Aide\Enum\Factory;

enum HttpMethod
{
    use Factory;

    case Get;
    case Post;
    case Put;
    case Head;
    case Options;
}

Info

Gather information regarding the current Enum via public static methods. This trait enables getting:

• the number of cases via the size method;
• the type of enum via the isBacked and isPure method;
• the names of each cases with the names method;
• the possible values for the Enum with the values method;
• the nameOf which returns the name associated with a specific value

<?php

HttpMethod::size();        //returns the number of cases
HttpMethod::isBacked();
HttpMethod::isPure();      // returns the inverse of the `isBacked` method
HttpMethod::names();       // returns a list of all the names in the enumeration
HttpMethod::values();      // returns a list of all the names in the enumeration
HttpMethod::nameOf(404);   // returns the name associated with the given value
                           // or null if it does not exist for the submitted value.

You need the Bakame\Aide\Enum\Info trait to expose the new API.

<?php

use Bakame\Aide\Enum\Info;

enum HttpMethod: string
{
    use Info;

    case Get = 'GET';
    case Post = 'POST';
    case Put = 'PUT';
    case Head = 'HEAD';
    case Options = 'OPTIONS'
}

Hasser/Isser methods

Enables asking whether some data are present in the Enum

<?php

HttpMethod::hasName('GET'); //returns false;
HttpMethod::hasValue('GET'); //returns true;
HttpMethod::has('Head'); //returns true;
HttpMethod::hasCase('Header', 'HEAD'); //returns false;

hasValue and hasCase will always return false for a Pure enumeration.

You need the Bakame\Aide\Enum\Hasser trait to expose the new API.

<?php

use Bakame\Aide\Enum\Hasser;

enum HttpMethod: string
{
    use Hasser;

    case Get = 'GET';
    case Post = 'POST';
    case Put = 'PUT';
    case Head = 'HEAD';
    case Options = 'OPTIONS'
}

Comparison

The Compare trait which adds four (4) methods to compare Enums instances. The equals and notEquals methods do strict comparison whereas isOneOf and isNotOneOf do loose comparison taking into account the value or the name of the Enum.

<?php

HttpMethod::Get->equals(HttpMethod::Post);      //returns false
HttpMethod::Get->isOneOf('GET', 'Get', 'get');  //returns true because `Get` is present
HttpMethod::Get->notEquals('get');              //returns true;
HttpMethod::Get->isNotOneOf('Head');            //returns true;

You need the Bakame\Aide\Enum\Compare trait to expose the new API.

<?php

use Bakame\Aide\Enum\Compare;

enum HttpMethod: string
{
    use Compare;

    case Get = 'GET';
    case Post = 'POST';
    case Put = 'PUT';
    case Head = 'HEAD';
    case Options = 'OPTIONS'
}

Convert

The Convert trait adds three (3) methods to convert Enums instances. The toAssociative converts the Enum instance into an associative array whereas the toJavaScriptObject and toJavaScriptClass methods convert the Enum into a JavaScript equivalent structure.

<?php

HttpMethod::toAssociative(); // returns tha associative array
HttpMethod::toJavaScriptObject();  // returns a JavaScript object equivalent code as string
HttpMethod::toJavaScriptClass();  // returns a JavaScript class equivalent code as string

You need the Bakame\Aide\Enum\Convert trait to expose the new API.

<?php

use Bakame\Aide\Enum\Convert;

enum HttpMethod: string
{
    use Convert;

    case Get = 'GET';
    case Post = 'POST';
    case Put = 'PUT';
    case Head = 'HEAD';
    case Options = 'OPTIONS'
}

All in one

If you want to apply all the traits together just use the single one which encompass all the traits already mentioned Bakame\Aide\Enum\Helper. Once added to your enum all the methods described here will be made available to your codebase.

You need the Bakame\Aide\Enum\Helper to expose the new API.

<?php

use Bakame\Aide\Enum\Helper;

enum HttpMethod: string
{
    use Helper;

    case Get = 'GET';
    case Post = 'POST';
    case Put = 'PUT';
    case Head = 'HEAD';
    case Options = 'OPTIONS'
}

Converting the Enum into a JavaScript structure

While the Convert::toJavaScriptObject and Convert::toJavaScriptClass methods are enough to convert your Enum to JavaScript code, behind the scene the method makes use of the JavaScriptConverter class. The class enables returning a more fine-tuned representation that suite your constraints better.

Because there are two (2) ways to create an Enum like structure in JavaScript, the class provides two (2) methods to allow the conversion.

In both cases, the conversion is configurable via wither methods to control the formatting and the JavaScript structure properties.

Backed Enum

For instance, given I have the following enum:

enum HttpStatusCode: int
{
    case HTTP_OK = 200;
    case HTTP_REDIRECTION = 302;
    case HTTP_NOT_FOUND = 404;
    case HTTP_SERVER_ERROR = 500;
}

It can be converted into an object using the convertToObject method:

use Bakame\Aide\Enum\JavaScriptConverter;

echo JavaScriptConverter::new()->convertToObject(HttpStatusCode::class);

will produce the following JavaScript code snippet:

const HttpStatusCode = Object.freeze({
  HTTP_OK: 200,
  HTTP_REDIRECTION: 302,
  HTTP_NOT_FOUND: 404,
  HTTP_SERVER_ERROR: 500
})

conversely using convertToClass as follows:

echo JavaScriptConverter::new()->convertToClass(HttpStatusCode::class);

will produce the following JavaScript code snippet:

class HttpStatusCode {
  static HTTP_OK = new HttpStatusCode(200)
  static HTTP_REDIRECTION = new HttpStatusCode(302)
  static HTTP_NOT_FOUND = new HttpStatusCode(404)
  static HTTP_SERVER_ERROR = new HttpStatusCode(500)
    
  constructor(name) {
    this.name = name
  }
}

Of course there are ways to improve the output depending on your use case you can

• ignore or use object immutability;
• ignore or use JavaScript export or export default;
• change the class name or add and/or change the object variable name;
• use Symbol when declaring the object property value;
• define indentation spaces and thus end of line;
• define the presence or absence of a trailing comma in the object representation;

Here's a more advance usage of the converter to highlight how you can configure it.

<?php
use Bakame\Aide\Enum\JavaScriptConverter;
use Illuminate\Support\Str;

$converter = JavaScriptConverter::new()
    ->useImmutability()
    ->useExportDefault()
    ->useTrailingComma()
    ->useSymbol()
    ->indentSize(4)
    ->propertyNameCase(
        fn (string $name) => Str::of($name)->replace('HTTP_', '')->lower()->studly()->toString()
    );

echo $converter->convertToObject(HttpStatusCode::class, 'StatusCode');

will return the following JavaScript code:

const StatusCode = Object.freeze({
    Ok: Symbol(200),
    Redirection: Symbol(302),
    NotFound: Symbol(404),
    ServerError: Symbol(500),
});
export default StatusCode;

Pure Enum

For Pure PHP Enum, the converter will assign a unique Symbol value for each case, starting wih the Symbol(0) and following the PHP order of case declaration. you can optionally configure the start value using the startAt method.

Let's take the following PHP Pure Enum:

enum Color
{
    case Red;
    case Blue;
    case Green;
}

It can be converted into an object using the convertToObject method:

use Bakame\Aide\Enum\JavaScriptConverter;

echo JavaScriptConverter::new()->convertToObject(Color::class);

will produce the following JavaScript code snippet:

const Color = Object.freeze({
  Red: Symbol(0),
  Blue: Symbol(1),
  Green: Symbol(2)
})

If you set up the starting value to increment you will get a different value:

use Bakame\Aide\Enum\JavaScriptConverter;

echo JavaScriptConverter::new()
    ->ignoreSymbol()
    ->valueStartAt(2)
    ->convertToClass(Color::class, 'Colour');

Then the start at value will be taken into account as shown below:

class Colour {
  static Red = new Colour(Symbol(2))
  static Blue = new Colour(Symbol(3))
  static Green = new Colour(Symbol(4))

  constructor(name) {
    this.name = name
  }
}

Caution

For Pure Enum the ignoreSymbol and useSymbol methods have no effect on the output.

Storing the output

The converter will not store the resulting string into a Javascriot file as this part is left to the discretion of the implementor. There are several ways to do so:

• using vanilla PHP with file_put_contents or SplFileObject
• using more robust and battle tested packages you can find on packagist for instance.

Credits

• ignace nyamagana butera
• All Contributors