DI Container

status: ready to use phpstan: level 8 phpunit: full

The Container helps configure an application. The implementation is compatible with PSR-11 ContainerInterface.

Main features:

• stores values as is (primitive, objects etc).
• creates a shared object (singleton).
• creates a fresh copy of the same class on each call.
• multi ability to create a different instance of the same class by provided keys.
• promises - container creates an instance only on a get call, to avoid unused creations.
• can detect a circular dependency

Latest version

v2.0.0

Install

composer install romchik38/php-container

Quick examples

Primitive

Primitive class is responsible to hold a static mixed value. Use method add to store it.

$container = new \Romchik38\Container\Container();
$container->add('some key', 'any string');
$container->add('config', ['key' => 0]);
$container->add('important_object', new ImportantClass());
// somewhere in the code
$str = $container->get('some key');
// ...etc

Shared

Shared class is responsible to create only one instance of concrete class and returns it on each get request. Use method shared there.

$container = new \Romchik38\Container\Container();
$container->shared(
    '\Classes\Primitive1',                 // class name
    [7]                                    // params, number 7 in this case
);
// $shared1 and $shared2 are the same
$shared1 = $container->get('\Classes\Primitive1');
$shared2 = $container->get('\Classes\Primitive1');

Fresh

Fresh class is responsible to create a new instance of concrete class on each get request. Use method fresh of the container.

$container = new \Romchik38\Container\Container();
$container->fresh(
    '\Classes\Primitive1',                  // class name
    [7]                                     // params, number 7 in this case
);
// $fresh1 and $fresh2 are defferent objects that hold the same number 7
$fresh1 = $container->get('\Classes\Primitive1');
$fresh2 = $container->get('\Classes\Primitive1');

Multi

Multi class is responsible to create a new (or shared) copy of a concrete class with a given key. It maght be usefull when dealing with interfaces or creating a few same classes with different configuration. Use method multi.

// Interface example
$container = new \Romchik38\Container\Container();
$container->multi(
    '\DB\DatabaseUseSql',
    '\DatabaseInterface',
    true,                           // true - shared, false - fresh
    ['dsn:localhost']               // params
);

$database = $container->get('\DatabaseInterface');

Promises

Promise is responsible to defer a creation of the class's dependency. It used when a class has another class as a dependency.

Promises can be used with methods shared, fresh and multi.

$container = new \Romchik38\Container\Container();
$container->shared(
    '\DB\Database', 
    [
        'db:mysql',                         // first param as a string
        new Promise('\SomeConnection'),     // second param as a promise
    ]
);

In the example above, we promise to add a class \SomeConnection to the container. \SomeConnection is a class name, but it can be any key, used with multi method. In other words we pass a container key as a param.

Do not forget to add a \SomeConnection

$container->fresh(
    '\SomeConnection',     // class name
    []                     // params, in that case is nothing
);

Circular dependency detection

We can primise to add the first class to another, and a the second class to the first and so on. Promise chain can be as long as you want. But if you try to add a class as a promise which depends on any early promised classes an exception will be thrown.

$container = new \Romchik38\Container\Container();

$container->shared(
    '\ClassA1', 
    [new Promise('\ClassA2')]
);

$container->shared(
    '\ClassA2', 
    [new Promise('\ClassA1')]
);
// Exception there

Code quality

• phpstan level 8
  • [OK] No errors
• phpunit
  • OK (36 tests, 54 assertions)
  • tested partially
• laminas-coding-standard
  • 32 / 32 (100%)