Introduction

The dependencies package is a simple package which allows you to sort dependencies, be it assets, simple strings, or class instances. It's clever enough to avoid circular dependencies in a never-ending loop.

The package requires PHP 7.2+ and follows the FIG standard PSR-0 to ensure a high level of interoperability between shared PHP code and is unit-tested.

Installation

The best and easiest way to install the Dependencies package is with Composer.

Preparation

Open your composer.json file and add the following to the require array:

"cartalyst/dependencies": "^2.0"

Note: Make sure that after the required changes your composer.json file is valid by running composer validate.

Install the dependencies

Run Composer to install or update the new requirement.

php composer install

or

php composer update

Now you are able to require the vendor/autoload.php file to autoload the package.

Usage

In this section we'll show how you can make use of the extensions package.

Basic Usage

use Cartalyst\Dependencies\DependencySorter;

$sorter = new DependencySorter();

// Add a "foo" item who depends on "bar" and "baz"
$sorter->add('foo', ['bar', 'baz']);
$sorter->add('baz');
$sorter->add('bar', 'baz');

var_dump($sorter->sort()); // Will spit out ['baz', 'bar', 'foo']

// Circular dependencies are recognized and an exception
// will be thrown rather than a never-ending sorting loop.
$sorter->add('foo', ['bar', 'baz']);
$sorter->add('baz');
$sorter->add('bar', 'foo');
var_dump($sorter->sort());

// UnexpectedValueException: Item [foo] and [bar] have a circular dependency.

DependentInterface

Our sorter also has the ability to take classes which implement Cartalyst\Dependencies\DependentInterface. Let's use the following, simplified asset example:

use Cartalyst\Dependencies\DependencySorter;
use Cartalyst\Dependencies\DependentInterface;

class Asset implements DependentInterface
{
    protected $slug;

    protected $path;

    protected $dependencies = [];

    public function __construct(string $slug, string arra $path, $dependencies = [])
    {
        $this->slug = $slug;

        $this->path = $path;

        $this->dependencies = $dependencies;
    }

    public function getSlug(): string
    {
        return $this->slug;
    }

    public function getDependencies(): array
    {
        return $this->dependencies;
    }

    public function getPath(): string
    {
        return $this->path;
    }
}

// Queue assets in a Dependency Sorter instance
$sorter = new DependencySorter([
    new Asset('bootstrap', 'js/bootstrap-2.3.1.js', 'jquery'),
    new Asset('jquery', 'js/bootstrap-1.9.1.min.js'),
    new Asset('main', 'js/main.js', ['jquery', 'bootstrap']),
]);

$assets = $sorter->sort();

// In your view
@foreach ($assets as $asset)
    <script src="{{ $asset->getPath() }}"></script>
@endforeach