README

A tool to resolve callables and their arguments

Installation

install via composer

    "require": {
        "dariorieke/callable-resolver": "dev-master"
    }

Tests

run tests with the following command inside the repositories root:

./vendor/bin/phpunit  .\tests

Usage

Resolving callables

To resolve abstract callables to actual callables, use the resolve method. If the callable resolver fails to resolve the callable an CallableResolverExceptionInterface will be thrown:

use DarioRieke\CallableResolver\CallableResolver;
use DarioRieke\CallableResolver\Exception\CallableResolverExceptionInterface;

$callableResolver = new CallableResolver();


$abstractCallable = 'mySpecialFunction';

try {
    $callable = $callableResolver->resolveCallable($abstractCallable);
    call_user_func($callable);
} 
catch (CallableResolverExceptionInterface $e) {
    //could not resolve the callable
}

Possible abstract callables which can be resolved:

//closure
$abtractCallable1 = function() {};
//object without constructor arguments
//the callable resolver will create an instance of it 
$abtractCallable2 = ['SplQueue', 'rewind'];
//initialized object, regular callable
$abtractCallable3 = [new \SplQueue, 'rewind'];
// function name
$abtractCallable4 = 'phpinfo';
//static class method
$abtractCallable5 =  [TestClass::class, 'staticMethod'];
//static class method as string
$abtractCallable6 =  'TestClass::staticMethod';

If you pass in a PSR-11 Container into the CallableResolvers constructor, the resolver will try to gather any uninitialized class from the container. If no container is provided, the class will be initialized with new $class(), so constructor arguments are only possible in conjunction with a DI Container.

### Resolving arguments

> Note that currently you have to provide a PSR-7 request implementation to use the ArgumentResolver.

To resolve the arguments for your callables, use the ArgumentResolver. Its main functionality is to resolve arguments from PSR-11 containers for dependency injection and arguments from PSR-7 server requests.

The resolver resolves arguments with different argument provider strategies which are passed via the constructor. This way you can add your own argument providers.

use DarioRieke\CallableResolver\ArgumentResolver;
use DarioRieke\CallableResolver\ArgumentResolver\RequestArgumentProvider;
use DarioRieke\CallableResolver\ArgumentResolver\RequestAttributeArgumentProvider;
use DarioRieke\CallableResolver\ArgumentResolver\ServiceArgumentProvider;


$argumentResolver = new ArgumentResolver (
    //resolves the currently handled PSR-7 request
    new RequestArgumentProvider(),
    //resolves attributes from the PSR-7 request 
    new RequestAttributeArgumentProvider(), 
    //resolves arguments via the provided PSR-11 container 
    new ServiceArgumentProvider(/** PSR-11 implementation*/ $container),
);

Example of Argument Resolving:

/**
 * type hint the arguments to let the ArgumentRresolver autoresolve them
 * works with RequestInterface and Interfaces and Classes registered in the DependencyInjectionContainer 
 * @param  string                $task    argument from the PSR-7 ServerRequest 
 * @param  int                   $id      argument from the PSR-7 ServerRequest
 * @param  RequestInterface      $request injects the current request
 * @param  LoggerInterface       $logger  a logger implementation resolved by type hint
 *                                        via PSR-11 container
 */
$callable = function (string $task, int $id, Psr\Http\Message\RequestInterface $request, LoggerInterface $logger) {
    // code
}

$args = $argumentResolver->resolveArguments($callable);

call_user_func_array($callable, $args);

Usage with DarioRieke\DependencyInjection\DependencyInjectionContainerInterface:

This interface extends the PSR-11 ContainerInterface. To resolve parameters from it, use the ServiceParameterArgumentProvider and pass in a DependencyInjectionContainerInterface implementation to its constructor.

	new ArgumentResolver (
		//...
		new ServiceParameterArgumentProvider($container)
	);

Make sure you have installed the "dariorieke/dependency-injection" package to use this argument provider.