baublet/dependency-container

A simple, PSR-4 compliant dependency container.

DependencyContainer

, _(*1)

For simple dependency injection, _(*2)

Why?

Sometimes you need dependencies across your application, plugin, or some other system that doesn't itself have a way to handle it (e.g., WordPress). So include this project as a submodule and inject dependencies into your classes at your leisure. Use a container when you don't want to pollute your constructors with a ton of dependencies., _(*3)

This container also only loads dependencies when a class tries to access the dependency in question. That's why all of our injections are declared as functions. For more information on this, see below., _(*4)

It's PSR compliant, implementing the (proposed) Container interfaces for the API. If the API changes in the interfaces, I'll update these to match., _(*5)

This means that the API for this is subject to change, so please read any documentation before upgrading., _(*6)

Installation

Add baublet/dependency-container to the required packages portion of your composer.json file, or, from the command line:, _(*7)

composer require baublet/dependency-container

Example

I've tried to make the API fairly simple. First, require the container module and declare a new container., _(*8)

use baublet\DependencyContainer\DependencyContainer;

$dependencies = new DependencyContainer();

Dependencies are declared as functions, so that you can ensure your dependencies are only loaded when called. This allows you to use this container as a registry of dependencies in a particular module that, when called, may or may not use all of its dependencies in a given call., _(*9)

To declare a dependency:, _(*10)

$constructor = "This will be passed to the function as $args";

$dependencies->set("my-dependency", function($args) {
    require_once("some/big/dependency/class.php");
    return new SomeBigDependencyClass($args);
}, $constructor);

In the above code, some/big/dependency/class.php is only required and SomeBigDependencyClass is only initialized when you call $dependencies->get("my-dependency");., _(*11)

Testing

This code is tested using Travis CI and plain PHP assertions. No testing framework required. Just hop into the test directory and run the test:, _(*12)

php test.php