BoundMethod.php

TLDR

This file defines the BoundMethod class in the Illuminate\Container namespace. It provides methods for calling a closure or a class method and injecting its dependencies.

Methods

call

This static method is used to call the given closure or class method and inject its dependencies.

callClass

This protected method is used to call a string reference to a class using the Class@method syntax.

callBoundMethod

This protected method is used to call a method that has been bound to the container.

normalizeMethod

This protected method is used to normalize a callback into the Class@method syntax.

getMethodDependencies

This protected method is used to get all the dependencies for a given method. It uses reflection to analyze the method's parameters and adds the corresponding dependencies to the result array.

getCallReflector

This protected method is used to get the proper reflection instance for the given callback.

addDependencyForCallParameter

This protected method is used to add the dependency for the given call parameter to the dependencies array.

isCallableWithAtSign

This protected method is used to determine if the given string is in Class@method syntax.

<?php

namespace Illuminate\Container;

use Closure;
use Illuminate\Contracts\Container\BindingResolutionException;
use InvalidArgumentException;
use ReflectionFunction;
use ReflectionMethod;

class BoundMethod
{
    /**
     * Call the given Closure / class@method and inject its dependencies.
     *
     * @param  \Illuminate\Container\Container  $container
     * @param  callable|string  $callback
     * @param  array  $parameters
     * @param  string|null  $defaultMethod
     * @return mixed
     *
     * @throws \ReflectionException
     * @throws \InvalidArgumentException
     */
    public static function call($container, $callback, array $parameters = [], $defaultMethod = null)
    {
        if (is_string($callback) && ! $defaultMethod && method_exists($callback, '__invoke')) {
            $defaultMethod = '__invoke';
        }

        if (static::isCallableWithAtSign($callback) || $defaultMethod) {
            return static::callClass($container, $callback, $parameters, $defaultMethod);
        }

        return static::callBoundMethod($container, $callback, function () use ($container, $callback, $parameters) {
            return $callback(...array_values(static::getMethodDependencies($container, $callback, $parameters)));
        });
    }

    /**
     * Call a string reference to a class using Class@method syntax.
     *
     * @param  \Illuminate\Container\Container  $container
     * @param  string  $target
     * @param  array  $parameters
     * @param  string|null  $defaultMethod
     * @return mixed
     *
     * @throws \InvalidArgumentException
     */
    protected static function callClass($container, $target, array $parameters = [], $defaultMethod = null)
    {
        $segments = explode('@', $target);

        // We will assume an @ sign is used to delimit the class name from the method
        // name. We will split on this @ sign and then build a callable array that
        // we can pass right back into the "call" method for dependency binding.
        $method = count($segments) === 2
                        ? $segments[1] : $defaultMethod;

        if (is_null($method)) {
            throw new InvalidArgumentException('Method not provided.');
        }

        return static::call(
            $container, [$container->make($segments[0]), $method], $parameters
        );
    }

    /**
     * Call a method that has been bound to the container.
     *
     * @param  \Illuminate\Container\Container  $container
     * @param  callable  $callback
     * @param  mixed  $default
     * @return mixed
     */
    protected static function callBoundMethod($container, $callback, $default)
    {
        if (! is_array($callback)) {
            return Util::unwrapIfClosure($default);
        }

        // Here we need to turn the array callable into a Class@method string we can use to
        // examine the container and see if there are any method bindings for this given
        // method. If there are, we can call this method binding callback immediately.
        $method = static::normalizeMethod($callback);

        if ($container->hasMethodBinding($method)) {
            return $container->callMethodBinding($method, $callback[0]);
        }

        return Util::unwrapIfClosure($default);
    }

    /**
     * Normalize the given callback into a Class@method string.
     *
     * @param  callable  $callback
     * @return string
     */
    protected static function normalizeMethod($callback)
    {
        $class = is_string($callback[0]) ? $callback[0] : get_class($callback[0]);

        return "{$class}@{$callback[1]}";
    }

    /**
     * Get all dependencies for a given method.
     *
     * @param  \Illuminate\Container\Container  $container
     * @param  callable|string  $callback
     * @param  array  $parameters
     * @return array
     *
     * @throws \ReflectionException
     */
    protected static function getMethodDependencies($container, $callback, array $parameters = [])
    {
        $dependencies = [];

        foreach (static::getCallReflector($callback)->getParameters() as $parameter) {
            static::addDependencyForCallParameter($container, $parameter, $parameters, $dependencies);
        }

        return array_merge($dependencies, array_values($parameters));
    }

    /**
     * Get the proper reflection instance for the given callback.
     *
     * @param  callable|string  $callback
     * @return \ReflectionFunctionAbstract
     *
     * @throws \ReflectionException
     */
    protected static function getCallReflector($callback)
    {
        if (is_string($callback) && str_contains($callback, '::')) {
            $callback = explode('::', $callback);
        } elseif (is_object($callback) && ! $callback instanceof Closure) {
            $callback = [$callback, '__invoke'];
        }

        return is_array($callback)
                        ? new ReflectionMethod($callback[0], $callback[1])
                        : new ReflectionFunction($callback);
    }

    /**
     * Get the dependency for the given call parameter.
     *
     * @param  \Illuminate\Container\Container  $container
     * @param  \ReflectionParameter  $parameter
     * @param  array  $parameters
     * @param  array  $dependencies
     * @return void
     *
     * @throws \Illuminate\Contracts\Container\BindingResolutionException
     */
    protected static function addDependencyForCallParameter($container, $parameter,
                                                            array &$parameters, &$dependencies)
    {
        if (array_key_exists($paramName = $parameter->getName(), $parameters)) {
            $dependencies[] = $parameters[$paramName];

            unset($parameters[$paramName]);
        } elseif (! is_null($className = Util::getParameterClassName($parameter))) {
            if (array_key_exists($className, $parameters)) {
                $dependencies[] = $parameters[$className];

                unset($parameters[$className]);
            } elseif ($parameter->isVariadic()) {
                $variadicDependencies = $container->make($className);

                $dependencies = array_merge($dependencies, is_array($variadicDependencies)
                            ? $variadicDependencies
                            : [$variadicDependencies]);
            } else {
                $dependencies[] = $container->make($className);
            }
        } elseif ($parameter->isDefaultValueAvailable()) {
            $dependencies[] = $parameter->getDefaultValue();
        } elseif (! $parameter->isOptional() && ! array_key_exists($paramName, $parameters)) {
            $message = "Unable to resolve dependency [{$parameter}] in class {$parameter->getDeclaringClass()->getName()}";

            throw new BindingResolutionException($message);
        }
    }

    /**
     * Determine if the given string is in Class@method syntax.
     *
     * @param  mixed  $callback
     * @return bool
     */
    protected static function isCallableWithAtSign($callback)
    {
        return is_string($callback) && str_contains($callback, '@');
    }
}