README

Caution!

This is the documentation for Pimple 2.x. If you are using Pimple 1.x, read the Pimple 1.x documentation. Reading the Pimple 1.x code is also a good way to learn more about how to create a simple Dependency Injection Container (Pimple 2.x implementation being more focused on performance).

Pimple is a small Dependency Injection Container for PHP that consists of just one file and one class (about 80 lines of code).

Installation

To include Pimple in your project, add it to your composer.json file:

{
    "require": {
        "pimple/pimple": "~2.1"
    }
}

Pimple is also available as a PHP C extension:

$ cd ext/pimple
$ phpize
$ ./configure
$ make
$ make install

Usage

Creating a container is a matter of instating the Container class

use Pimple\Container;

$container = new Container();

Note

In Pimple 2.0, the class Pimple\Container was named Pimple (a class alias is automatically registered to keep backward compatibility, but you should upgrade your code.)

As many other dependency injection containers, Pimple is able to manage two different kind of data: services and parameters.

Defining Parameters

Defining a parameter is as simple as using the Pimple instance as an array

// define some parameters
$container['cookie_name'] = 'SESSION_ID';
$container['session_storage_class'] = 'SessionStorage';

Defining Services

A service is an object that does something as part of a larger system. Examples of services: Database connection, templating engine, mailer. Almost any object could be a service.

Services are defined by anonymous functions that return an instance of an object

// define some services
$container['session_storage'] = function ($c) {
    return new $c['session_storage_class']($c['cookie_name']);
};

$container['session'] = function ($c) {
    return new Session($c['session_storage']);
};

Notice that the anonymous function has access to the current container instance, allowing references to other services or parameters.

As objects are only created when you get them, the order of the definitions does not matter, and there is no performance penalty.

Using the defined services is also very easy

// get the session object
$session = $container['session'];

// the above call is roughly equivalent to the following code:
// $storage = new SessionStorage('SESSION_ID');
// $session = new Session($storage);

Protecting Parameters

Because Pimple sees anonymous functions as service definitions, you need to wrap anonymous functions with the protect() method to store them as parameter

$container['random'] = $container->protect(function () { return rand(); });

Modifying services after creation

In some cases you may want to modify a service definition after it has been defined. You can use the extend() method to define additional code to be run on your service just after it is created

$container['mail'] = function ($c) {
    return new \Zend_Mail();
};

$container->extend('mail', function($mail, $c) {
    $mail->setFrom($c['mail.default_from']);

    return $mail;
});

The first argument is the name of the object, the second is a function that gets access to the object instance and the container.

Fetching the service creation function

When you access an object, Pimple automatically calls the anonymous function that you defined, which creates the service object for you. If you want to get raw access to this function, you can use the raw() method

$container['session'] = function ($c) {
    return new Session($c['session_storage']);
};

$sessionFunction = $container->raw('session');

Extending a Container

.. versionadded:: 2.1

    Support for extending a container was introduced in Pimple 2.1.

If you use the same libraries over and over, you might want to reuse some services from one project to the other; package your services into a provider by implementing Pimple\ServiceProviderInterface:

use Pimple\Container;

class FooProvider implements Pimple\ServiceProviderInterface
{
    public function register(Container $pimple)
    {
        // register some services and parameters
        // on $pimple
    }
}

Then, the provider can be easily registered on a Container:

$pimple->register(new FooProvider());

Defining Factory Services

By default, each time you get a service, Pimple returns the same instance of it. If you want a different instance to be returned for all calls, wrap your anonymous function with the factory() method

$container['session'] = $container->factory(function ($c) {
    return new Session($c['session_storage']);
});

trigig / pimple_fixed

Maintainers

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