PHP Enum and examples in Laravel

Enum helps you to write more readable and maintainable code.

There are many reasons why you want to use enums:

• DRY — You don’t want to repeat yourself. Having duplicated code is not easy to maintain. With enums, you have a single file to maintain for some related values.
• Consistency — You want to ensure some values are the same through your code.
• Leave the Database alone — Yeah, you don’t want to make costly queries to your database just to retrieve some static values

In these examples, I will show you how I use enum in Laravel/Vue

Enum helper trait for returning values

<?php
namespace App\Traits;
trait EnumValues
{
    public static function values(): array
    {
      return array_column(self::cases(), 'value');
    }
}

Enum helper trait for returning options

<?php
namespace App\Traits;
use Illuminate\Support\Str;
trait EnumOptions
{
    public static function options(): array
    {
        $cases   = static::cases();
        $options = [];
        foreach($cases as $case){
            $label = $case->name;
            if(Str::contains($label, '_')){
                $label = Str::replace('_', ' ', $label);
            }
$options[] = [
                'value' => $case->value, 
                'label' => Str::title($label)
            ];
        }
        return $options;
    }
}

An enum for related status

<?php
namespace App\Enums;
use App\Traits\{EnumOptions,EnumValues};
enum LoanRequestStatus: string 
{
    use EnumValues;
    use EnumOptions;
    case PENDING    = 'pending';
    case APPROVED   = 'approved';
    case PAID       = 'paid';
    case UNPAID     = 'unpaid';
    case REPAID     = 'repaid';
    case REJECTED   = 'rejected';
    case CLOSED     = 'closed';
    case ADJUSTED   = 'adjusted';
    case WORKFLOW   = 'workflow';
    case ON_HOLD    = 'on-hold';
}

How I use enum in the migration file

<?php
use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;
use App\Enums\LoanRequestStatus;
return new class extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('loan_requests', function (Blueprint $table)        {
            $table->id();
            $table->enum('status', LoanRequestStatus::values());
        });
    }
/**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('loan_requests');
    }
};

Use as option

// in controller
return response([
  'statuses' => LoanRequestStatus::options()
]);
// In vue
<select-input v-model="form.status" label="Status">
  <option :value="null" />
  <option v-for="status in statuses" :value="status.value">
   {{status.label}}
  </option>
</select-input>

Use in validation

<?php
namespace App\Http\Requests\LoanRequest;
use Illuminate\Foundation\Http\FormRequest;
use Illuminate\Validation\Rule;
use App\Enums\LoanRequestStatus;
class StoreLoanRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }
/**
     * Get the validation rules that apply to the request.
     *
     * @return array<string, mixed>
     */
    public function rules()
    {
        return [
            'status' => Rule::in(LoanRequestStatus::values())
        ];
    }
}

Use in Model

<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Builder;
use Illuminate\Database\Eloquent\SoftDeletes;
use Illuminate\Database\Eloquent\Casts\Attribute;
use App\Enums\LoanRequestStatus;
class LoanRequest extends Model
{
    use HasFactory;
    use SoftDeletes;
/**
     * The attributes that are mass assignable.
     *
     * @var array
     */
    protected $fillable = [
        'status'
    ];
/**
     * The attributes that should be cast.
     *
     * @var array
     */
    protected $casts = [
        'is_pending' => 'boolean',
        'status'     => LoanRequestStatus::class
    ];
protected function isPending(): Attribute
    {
        return Attribute::make(
            get: fn($value) => $this->status == LoanRequestStatus::PENDING
        );
    }
}

There you go! Start using enums where necessary :))
NB: This is currently supported in PHP 8.1
https://www.php.net/manual/en/language.enumerations.php

I’m also running the Latest Laravel version at the time of this writeup, which is Laravel 9.1