README

Dependency Injection for PHP.

We use semantic version. See our releases.

Classes

• phputil\DI

Installation

composer require phputil/di

Example 1: automatic injection without configuring anything

class A {}
class B {}

class C {
	public $a, $b;
	function __construct( A $a, B $b ) {
		$this->a = $a;
		$this->b = $b;
	}
}

// Automatically creates "A" and "B", and inject them in "C"
$c = DI::create( 'C' );

Example 2: configuring the injection for interfaces

interface MyInterface {
	function say( $what );
}

class MyClass implements MyInterface {
	function say( $what ) { echo $what; }
}

// Configures "MyInterface" to be created using "MyClass"
DI::config( DI::let( 'MyInterface' )->create( 'MyClass' ) );

$foo = DI::create( 'MyClass' ); // Create an instance of MyClass (no configuration required)
$foo->say( 'hello' );

$bar = DI::create( 'MyInterface' ); // Create an instance of MyClass!
$bar->say( 'world' );

Example 3: a more complex model

interface I {}

class A {}

class B implements I {}

class C {
	public $i;
	function __construct( I $i ) {
		$this->i = $i;
	}
}

class X {
	public $a, $c;
	function __construct( A $a, C $c ) {
		$this->a = $a;
		$this->c = $c;
	}
}

// Configures "I" to be created using "B"
DI::config( DI::let( 'I' )->create( 'B' ) );

// Automatically creates and injects "A" and "C", and
// when creates "C", also injects "B" as "I".
$x = DI::create( 'X' );

Example 4: passing constructor's arguments

class A {
	function __construct( $one, $two = 'world' ) {
		echo $one, ', ', $two;
	}
}

// Creates "A", passing constructor arguments as an array
$a = DI::create( 'A', array( 'hello' ) ); // prints hello, world

Example 5: configuring shared instances

class A {}

// Makes "A" a shared instance
DI::config( DI::let( 'A' )->shared() );

$a1 = DI::create( 'A' );
$a2 = DI::create( 'A' );
var_dump( $a1 === $a2 ); // bool(true)

Example 6: configuring shared instances for interfaces

interface I {}

class C implements I {}

// Makes "I" a shared instance
DI::config( DI::let( 'I' )->create( 'C' )->shared() );

$i1 = DI::create( 'I' );
$i2 = DI::create( 'I' );
var_dump( $i1 === $i2 ); // bool(true)

Example 7: defining a creation function

interface I {}

class C implements I {}

// Let you using a callable to create the desired instance
DI::config( DI::let( 'I' )->call( function() {
		return new C();
	} ) );

$i = DI::create( 'I' ); // Calls your function to create a "C" instance

Example 8: passing arguments for creation functions

class A {
	private $text;
	function __construct( $text ) {
		$this->text = $text;
	}
}

// Lets you customize a callable with parameters
DI::config( DI::let( 'A' )->call( function( $a, $b ) {
		return new A( $a . $b );
	} ) );

// Uses the customized constructor
$a = DI::create( 'A', array( 'Hello, ', 'world' ) );
echo $a->text(); // Hello, world

// Ignore the customized constructor passing true after the parameters
$a2 = DI::create( 'A', array( 'Hi!' ), true );
echo $a2->text(); // Hi