README

Important

This repository is a read-only mirror of the utopia-php monorepo. Development happens in packages/di — please open issues and pull requests there.

Utopia DI is a small PSR-11 compatible dependency injection container with parent-child scopes. It is designed to stay simple while still covering the dependency lifecycle used across the Utopia libraries. This library is maintained by the Appwrite team.

Although this library is part of the Utopia Framework project it is dependency free, and can be used as standalone with any other PHP project or framework.

Getting Started

Install using Composer:

composer require utopia-php/di

require_once __DIR__.'/../vendor/autoload.php';

use Utopia\DI\Container;

$di = new Container();

$di->set('age', fn (): int => 25);

$di->set(
    'john',
    fn (int $age): string => 'John Doe is '.$age.' years old.',
    ['age']
);

$john = $di->get('john');

Dependencies are resolved from the third set() argument and passed to the factory in that same order.

Register factories directly and list the dependency IDs they need.

$di->set('config', fn (): array => [
    'dsn' => 'mysql:host=localhost;dbname=app',
    'username' => 'root',
    'password' => 'secret',
]);

$di->set(
    'db',
    fn (array $config): PDO => new PDO(
        $config['dsn'],
        $config['username'],
        $config['password']
    ),
    ['config']
);

Factories are resolved once per container instance. A child container behaves in two distinct ways:

• If the child does not define a key, it falls back to the parent and reuses the parent's resolved value.
• If the child defines the same key locally, it resolves and caches its own value without changing the parent.

$counter = 0;

$di->set('requestId', function () use (&$counter): string {
    $counter++;

    return 'request-'.$counter;
});

$di->get('requestId'); // "request-1"

$child = new Container($di);

$child->get('requestId'); // "request-1" (falls back to the parent cache)

$child->set('requestId', function () use (&$counter): string {
    $counter++;

    return 'request-'.$counter;
});

$child->get('requestId'); // "request-2" (child now uses its own local definition)
$di->get('requestId'); // "request-1" (parent is unchanged)

System Requirements

Utopia DI requires PHP 8.2 or later. We recommend using the latest PHP version whenever possible.

More from Utopia

Our ecosystem supports other thin PHP projects aiming to extend the core PHP Utopia libraries.

Each project is focused on solving a single, very simple problem and you can use composer to include any of them in your next project.

You can find all libraries in GitHub Utopia organization.

Contributing

All code contributions - including those of people having commit access - must go through a pull request and approved by a core developer before being merged. This is to ensure proper review of all the code.

Fork the project, create a feature branch, and send us a pull request.

You can refer to the Contributing Guide for more info.

For security issues, please email security@appwrite.io instead of posting a public issue in GitHub.

Copyright and license

The MIT License (MIT) http://www.opensource.org/licenses/mit-license.php