Dice PHP Dependency Injection Container

Dice is a minimalist Dependency Injection Container for PHP with a focus on being lightweight and fast as well as requiring as little configuration as possible.

Project Goals

1. To be lightweight and not a huge library with dozens of files (Dice is a single 100 line class) yet support all features (and more) offered by much more complex containers

2. To "just work". Basic functionality should work with zero configuration

3. Where configuration is required, it should be as minimal and reusable as possible as well as easy to use.

4. Speed! (See the section on performance)

Installation

Just include the lightweight Dice.php in your project and it's usable without any further configuration:

Simple example:

<?php
class A {
	public $b;
	
	public function __construct(B $b) {
		$this->b = $b;
	}
}

class B {

}

require_once 'Dice.php';
$dice = new \Dice\Dice;

$a = $dice->create('A');

var_dump($a->b); //B object

?>

Full Documentation

For complete documentation please see the Dice PHP Dependency Injection container home page

PHP version compatibility

Dice is compatible with PHP5.4 and up, there are archived versions of Dice which supports PHP5.3 however this is no longer maintanied.

Performance

Dice uses reflection which is often wrongly labelled "slow". Reflection is considerably faster than loading and parsing a configuration file. There are a set of benchmarks here and here (To download the benchmark tool yourself see this repository) and Dice is faster than the others in most cases.

In the real world test (test 6) Dice is neck-and-neck with Pimple (which requires writing an awful lot of configuration code) and although Symfony\DependencyInjection is faster at creating objects, it has a larger overhead and you need to create over 500 objects on each page load until it becomes faster than Dice. The same is true of Phalcon, the overhead of loading the Phalcon extension means that unless you're creating well over a thousand objects per HTTP request, the overhead is not worthwhile.

Credits

Originally developed by Tom Butler (@TomBZombie), with many thanks to daniel-meister (@daniel-meister), Garrett W. (@garrettw), maxwilms (@maxwilms) for bug fixes, suggestions and improvements.

Updates

29/10/2014

• Based on Issue #15, Dice will now only call closures if they are wrapped in \Dice\Instance. **PLEASE NOTE: THIS IS BACKWARDS INCOMPATIBLE **.

Previously Dice ran closures that were passed as substitutions, constructParams and when calling methods:

$rule->substitutions['A'] = function() {
	return new A;
};

$rule->call[] = ['someMethod', function() {
// '2' will be provided as the first argument when someMethod is called
return 2;
}];

$rule->constructParams[] = function() {
	//'abc' will be providedas the first constructor parameter
	return 'abc';
};

This behaviour has changed as it makes it impossible to provide a closure as a construct parameter or when calling a method because the closure was always called and executed.

To overcome this, Dice will now only call a closures if they're wrapped in \Dice\Instance:

$rule->substitutions['A'] = new \Dice\Instance(function() {
	return new A;
});

$rule->call[] = ['someMethod', new \Dice\Instance(function() {
// '2' will be provided as the first argument when someMethod is called
return 2;
}]);

$rule->constructParams[] = new \Dice\Instance(function() {
	//'abc' will be providedas the first constructor parameter
	return 'abc';
});

04/09/2014

• Pushed PHP5.6 branch live. This is slightly more efficient using PHP5.6 features. For PHP5.4-PHP5.5 please see the relevant branch. This version will be maintained until PHP5.6 is more widespread.

26/08/2014

• Added PHP5.6 branch. Tidied up code by using PHP5.6 features. This will be moved to master when PHP5.6 is released

28/06/2014

• Greatly improved efficienty. Dice is now the fastest Dependency Injection Container for PHP!

06/06/2014

• Added support for cyclic references ( https://github.com/TomBZombie/Dice/issues/7 ). Please note this is poor design but this fix will stop the infinite loop this design creates.

27/03/2014

• Removed assign() method as this duplicated functionality available using $rule->shared
• Removed $callback argument in $dice->create() as the only real use for this feature can be better achieved using $rule->shareInstances
• Tidied up code, removing unused/undocumented features. Dice is now even more lightweight and faster.
• Fixed a bug where when using $rule->call it would use the substitution rules from the constructor on each method called
• Updated Dice documentation to use shorthand array syntax

01/03/2014

• Added test cases for the Xml Loader and Loader Callback classes
• Added a JSON loader + test case
• Added all test cases to a test suite
• Moved to PHP5.4 array syntax. A PHP5.3 compatible version is now available in the PHP5.3 branch.
• Fixed an issue where using named instances would trigger the autoloader with an invalid class name every time a class was created

28/02/2014

• Added basic namespace support. Documentation update will follow shortly. Also moved the XML loader into its own file, you'll need to include it separately if you're using it.
• Please note: CHANGES ARE NOT BACKWARDS COMPATIBLE. However they are easily fixed by doing the following find/replaces:

	new Dice => new \Dice\Dice
	new DiceInstance => new \Dice\Instance
	new DiceRule => new \Dice\Rule