phpnomad/di

phpnomad/di is the contract-only dependency injection package for PHPNomad. It defines the interfaces a container has to satisfy (InstanceProvider, HasBindings, CanSetContainer), a HasSettableContainer trait for classes that need the container handed to them after construction, and a DiException type. That's the entire package. It has zero runtime dependencies.

The concrete container implementation lives in a separate package, phpnomad/di-container. This split exists so your code can depend on the contracts without forcing a specific container implementation on anyone downstream. You can swap the container for a different implementation without touching any of the classes that inject InstanceProvider. phpnomad/di-container is the standard implementation that ships with PHPNomad and has been running in production for years across Siren and several other client systems.

Installation

composer require phpnomad/di

Most applications also install phpnomad/di-container, which provides the concrete Container class that implements these interfaces:

composer require phpnomad/di-container

Quick Start

Classes declare InstanceProvider as a constructor parameter and use it to resolve dependencies by class name at runtime. Here's a report builder that needs a datastore it doesn't hold as a direct property:

<?php

namespace MyApp\Reporting;

use MyApp\Widgets\WidgetDatastore;
use PHPNomad\Di\Interfaces\InstanceProvider;

class ReportBuilder
{
    protected InstanceProvider $container;

    public function __construct(InstanceProvider $container)
    {
        $this->container = $container;
    }

    public function buildWidgetReport(int $widgetId): array
    {
        $datastore = $this->container->get(WidgetDatastore::class);
        $widget = $datastore->getById($widgetId);

        return [
            'id'    => $widget->getId(),
            'name'  => $widget->getName(),
            'total' => $widget->getTotal(),
        ];
    }
}

The container you inject only has to implement InstanceProvider. In a PHPNomad application that's typically PHPNomad\Di\Container\Container from phpnomad/di-container, but any implementation of the interface works.

Key Concepts

• InstanceProvider is the resolution contract. get(class-string $abstract) returns an autowired instance, or throws DiException if resolution fails.
• HasBindings is the binding contract. bind(concrete, abstract, ...abstracts) maps one concrete class to one or more abstracts, and bindFactory(abstract, callable) binds an abstract to a factory callable.
• CanSetContainer is the setter-injection interface for classes that need a container handed to them after construction rather than as a constructor argument. The HasSettableContainer trait implements it and stores the provider as a protected property.
• DiException is thrown when the container cannot resolve a requested class.

Documentation

Full PHPNomad documentation lives at phpnomad.com, including the bootstrapping guide that shows how containers, initializers, and facades fit together in a full application.

License

MIT, see LICENSE.txt for the full text.