使用接口和特征在 PHP 中编写灵活的枚举

<?php

namespace app\contracts;

interface enum
{
    /**
     * get the label for the enum case.
     *
     * @return string
     */
    public function label(): string;

    /**
     * get the description for the enum case.
     *
     * @return string
     */
    public function description(): string;

    /**
     * generate an array of options with value, label, and description for select inputs.
     *
     * @return array
     */
    public static function options(): array;
}

<?php

namespace app\concerns;

trait interactswithenumoptions
{
    /**
     * generate an array of options with value, label, and description for select inputs.
     *
     * @return array
     */
    public static function options(): array
    {
        return array_map(fn ($case) => [
            'value' => $case->value,
            'label' => $case->label(),
            'description' => $case->description(),
        ], self::cases());
    }
}

<?php

namespace app\enums;

use app\contracts\enum as contract;
use app\concerns\interactswithenumoptions;

enum serverstatus: string implements contract
{
    use interactswithenumoptions;

    case pending = 'pending';
    case running = 'running';
    case stopped = 'stopped';
    case failed = 'failed';

    public function label(): string
    {
        return match ($this) {
            self::pending => 'pending installation',
            self::running => 'running',
            self::stopped => 'stopped',
            self::failed => 'failed',
            default => throw new \exception('unknown enum value requested for the label'),
        };
    }

    public function description(): string
    {
        return match ($this) {
            self::pending => 'the server is currently being created or initialized.',
            self::running => 'the server is live and operational.',
            self::stopped => 'the server is stopped but can be restarted.',
            self::failed => 'the server encountered an error and is not running.',
            default => throw new \exception('unknown enum value requested for the description'),
        };
    }
}

<?php

namespace {{ namespace }};

use app\contracts\enum as contract;
use app\concerns\interactswithenumoptions;

enum {{ class }} implements contract
{
    use interactswithenumoptions;

    case example; // add actual cases here

    public function label(): string
    {
        return match ($this) {
            self::example => 'example label', // add labels for other cases
            default => throw new \exception('unknown enum value requested for the label'),
        };
    }

    public function description(): string
    {
        return match ($this) {
            self::example => 'this is an example description.', // add descriptions for other cases
            default => throw new \exception('unknown enum value requested for the description'),
        };
    }
}

<?php

namespace app\http\controllers;

use app\enums\serverstatus;

class servercontroller extends controller
{
    public function edit($id)
    {
        $server = server::findorfail($id);
        $statusoptions = serverstatus::options(); // get enum options using the trait

        return view('servers.edit', compact('server', 'statusoptions'));
    }
}

[
    ['value' => 'pending', 'label' => 'pending installation', 'description' => 'the server is currently being created or initialized.'],
    ['value' => 'running', 'label' => 'running', 'description' => 'the server is live and operational.'],
    // other cases...
]

@extends('layouts.app')

@section('content')
    <div class="container">
        <h1>Edit Server</h1>

        <form action="{{ route('servers.update', $server->id) }}" method="POST">
            @csrf
            @method('PUT')

            <!-- Other form fields -->

            <div class="mb-3">
                <label for="status" class="form-label">Server Status</label>
                <select name="status" id="status" class="form-control" onchange="updateDescription()">
                    @foreach ($statusOptions as $option)
                        <option value="{{ $option['value'] }}" 
                                @if ($server->status === $option['value']) selected @endif>
                            {{ $option['label'] }}
                        </option>
                    @endforeach
                </select>
            </div>

            <div id="statusDescription" class="alert alert-info">
                <!-- Default description when the page loads -->
                {{ $statusOptions[array_search($server->status, array_column($statusOptions, 'value'))]['description'] }}
            </div>

            <button type="submit" class="btn btn-primary">Update Server</button>
        </form>
    </div>

    <script>
        const statusOptions = @json($statusOptions);

        function updateDescription() {
            const selectedStatus = document.getElementById('status').value;
            const selectedOption = statusOptions.find(option => option.value === selectedStatus);
            document.getElementById('statusDescription').textContent = selectedOption ? selectedOption.description : '';
        }
    </script>
@endsection