README

A lightweight Laravel package that provides a highly accurate BigDecimal Eloquent Cast based on brick/math. Designed for financial, scientific, or high-precision calculations where standard PHP floats fail.

🚀 Features

• Casts database values into Brick\Math\BigDecimal
• Automatically converts the value back when saving
• Fully configurable precision (scale) and rounding mode
• Zero dependencies besides brick/math and Laravel support
• Auto-discovery support for Laravel
• Allows safe and precise arithmetic operations

📦 Installation

Install the package via Composer:

composer require au9500/laravel-big-decimal-cast

For development, you can load the package via a local path repository inside your application composer.json.

🛠 Usage

1. Add the cast to your Eloquent model

use Au9500\LaravelBigDecimalCast\Casts\BigDecimalCast;

class Product extends Model
{
    protected $casts = [
        'price' => BigDecimalCast::class,
    ];
}

2. Use it like a normal number — but with precision

$product = Product::find(1);

// BigDecimal instance
$price = $product->price;

// Add numbers with precision
$product->price = $product->price->plus('19.99');

$product->save();

⚙️ Configuration

Publish the configuration file:

php artisan vendor:publish --tag=big-decimal-cast-config

This will create:

config/big-decimal-cast.php

<?php

use Brick\Math\RoundingMode;

return [
    'scale' => 2,
    'rounding_mode' => RoundingMode::HALF_UP,
];

Change scale globally

'scale' => 4,

Now all casts will store values with 4 decimal places.

🔍 How It Works

Casting on retrieval:

return BigDecimal::of($value ?? 0);

Casting on save:

$scale = Config::get('big-decimal-cast.scale', 2);
$roundingMode = Config::get('big-decimal-cast.rounding_mode', RoundingMode::HALF_UP);

return $bigDecimal->toScale($scale, $roundingMode)->__toString();

🧪 Example Migration

Schema::create('products', function (Blueprint $table) {
    $table->id();
    $table->string('price');
    $table->timestamps();
});

Using a string or decimal column is recommended depending on precision needs.

🛡 Requirements

• PHP 8.2+
• Laravel 10 / 11 / 12
• brick/math ^0.11

📚 Why BigDecimal?

Float inaccuracies example:

0.1 + 0.2  // results in 0.30000000000000004

BigDecimal avoids this via arbitrary precision decimal arithmetic.

🤝 Contributing

1. Fork this repository
2. Create a feature branch
3. Commit your changes
4. Open a Pull Request

📄 License

This package is open-source and licensed under the MIT License.