php-di/src/Container.php

<?php

declare(strict_types=1);

namespace DI;

use DI\Definition\Definition;
use DI\Definition\Exception\InvalidDefinition;
use DI\Definition\FactoryDefinition;
use DI\Definition\Helper\DefinitionHelper;
use DI\Definition\InstanceDefinition;
use DI\Definition\ObjectDefinition;
use DI\Definition\Resolver\DefinitionResolver;
use DI\Definition\Resolver\ResolverDispatcher;
use DI\Definition\Source\DefinitionArray;
use DI\Definition\Source\MutableDefinitionSource;
use DI\Definition\Source\ReflectionBasedAutowiring;
use DI\Definition\Source\SourceChain;
use DI\Definition\ValueDefinition;
use DI\Invoker\DefinitionParameterResolver;
use DI\Proxy\ProxyFactory;
use InvalidArgumentException;
use Invoker\Invoker;
use Invoker\InvokerInterface;
use Invoker\ParameterResolver\AssociativeArrayResolver;
use Invoker\ParameterResolver\Container\TypeHintContainerResolver;
use Invoker\ParameterResolver\DefaultValueResolver;
use Invoker\ParameterResolver\NumericArrayResolver;
use Invoker\ParameterResolver\ResolverChain;
use Psr\Container\ContainerInterface;

/**
 * Dependency Injection Container.
 *
 * @api
 *
 * @author Matthieu Napoli <matthieu@mnapoli.fr>
 */
class Container implements ContainerInterface, FactoryInterface, InvokerInterface
{
    /**
     * Map of entries that are already resolved.
     * @var array
     */
    protected $resolvedEntries = [];

    /**
     * @var MutableDefinitionSource
     */
    private $definitionSource;

    /**
     * @var DefinitionResolver
     */
    private $definitionResolver;

    /**
     * Map of definitions that are already fetched (local cache).
     *
     * @var (Definition|null)[]
     */
    private $fetchedDefinitions = [];

    /**
     * Array of entries being resolved. Used to avoid circular dependencies and infinite loops.
     * @var array
     */
    protected $entriesBeingResolved = [];

    /**
     * @var InvokerInterface|null
     */
    private $invoker;

    /**
     * Container that wraps this container. If none, points to $this.
     *
     * @var ContainerInterface
     */
    protected $delegateContainer;

    /**
     * @var ProxyFactory
     */
    protected $proxyFactory;

    /**
     * Use `$container = new Container()` if you want a container with the default configuration.
     *
     * If you want to customize the container's behavior, you are discouraged to create and pass the
     * dependencies yourself, the ContainerBuilder class is here to help you instead.
     *
     * @see ContainerBuilder
     *
     * @param ContainerInterface $wrapperContainer If the container is wrapped by another container.
     */
    public function __construct(
        MutableDefinitionSource $definitionSource = null,
        ProxyFactory $proxyFactory = null,
        ContainerInterface $wrapperContainer = null
    ) {
        $this->delegateContainer = $wrapperContainer ?: $this;

        $this->definitionSource = $definitionSource ?: $this->createDefaultDefinitionSource();
        $this->proxyFactory = $proxyFactory ?: new ProxyFactory(false);
        $this->definitionResolver = new ResolverDispatcher($this->delegateContainer, $this->proxyFactory);

        // Auto-register the container
        $this->resolvedEntries = [
            self::class => $this,
            ContainerInterface::class => $this->delegateContainer,
            FactoryInterface::class => $this,
            InvokerInterface::class => $this,
        ];
    }

    /**
     * Returns an entry of the container by its name.
     *
     * @param string $name Entry name or a class name.
     *
     * @throws DependencyException Error while resolving the entry.
     * @throws NotFoundException No entry found for the given name.
     * @return mixed
     */
    public function get($name)
    {
        // If the entry is already resolved we return it
        if (isset($this->resolvedEntries[$name]) || array_key_exists($name, $this->resolvedEntries)) {
            return $this->resolvedEntries[$name];
        }

        $definition = $this->getDefinition($name);
        if (! $definition) {
            throw new NotFoundException("No entry or class found for '$name'");
        }

        $value = $this->resolveDefinition($definition);

        $this->resolvedEntries[$name] = $value;

        return $value;
    }

    /**
     * @param string $name
     *
     * @return Definition|null
     */
    private function getDefinition($name)
    {
        // Local cache that avoids fetching the same definition twice
        if (!array_key_exists($name, $this->fetchedDefinitions)) {
            $this->fetchedDefinitions[$name] = $this->definitionSource->getDefinition($name);
        }

        return $this->fetchedDefinitions[$name];
    }

    /**
     * Build an entry of the container by its name.
     *
     * This method behave like get() except resolves the entry again every time.
     * For example if the entry is a class then a new instance will be created each time.
     *
     * This method makes the container behave like a factory.
     *
     * @param string $name       Entry name or a class name.
     * @param array  $parameters Optional parameters to use to build the entry. Use this to force specific parameters
     *                           to specific values. Parameters not defined in this array will be resolved using
     *                           the container.
     *
     * @throws InvalidArgumentException The name parameter must be of type string.
     * @throws DependencyException Error while resolving the entry.
     * @throws NotFoundException No entry found for the given name.
     * @return mixed
     */
    public function make($name, array $parameters = [])
    {
        if (! is_string($name)) {
            throw new InvalidArgumentException(sprintf(
                'The name parameter must be of type string, %s given',
                is_object($name) ? get_class($name) : gettype($name)
            ));
        }

        $definition = $this->getDefinition($name);
        if (! $definition) {
            // If the entry is already resolved we return it
            if (array_key_exists($name, $this->resolvedEntries)) {
                return $this->resolvedEntries[$name];
            }

            throw new NotFoundException("No entry or class found for '$name'");
        }

        return $this->resolveDefinition($definition, $parameters);
    }

    /**
     * Test if the container can provide something for the given name.
     *
     * @param string $name Entry name or a class name.
     *
     * @throws InvalidArgumentException The name parameter must be of type string.
     * @return bool
     */
    public function has($name)
    {
        if (! is_string($name)) {
            throw new InvalidArgumentException(sprintf(
                'The name parameter must be of type string, %s given',
                is_object($name) ? get_class($name) : gettype($name)
            ));
        }

        if (array_key_exists($name, $this->resolvedEntries)) {
            return true;
        }

        $definition = $this->getDefinition($name);
        if ($definition === null) {
            return false;
        }

        return $this->definitionResolver->isResolvable($definition);
    }

    /**
     * Inject all dependencies on an existing instance.
     *
     * @param object $instance Object to perform injection upon
     * @throws InvalidArgumentException
     * @throws DependencyException Error while injecting dependencies
     * @return object $instance Returns the same instance
     */
    public function injectOn($instance)
    {
        if (!$instance) {
            return $instance;
        }

        $className = get_class($instance);

        // If the class is anonymous, don't cache its definition
        // Checking for anonymous classes is cleaner via Reflection, but also slower
        $objectDefinition = false !== strpos($className, '@anonymous')
            ? $this->definitionSource->getDefinition($className)
            : $this->getDefinition($className);

        if (! $objectDefinition instanceof ObjectDefinition) {
            return $instance;
        }

        $definition = new InstanceDefinition($instance, $objectDefinition);

        $this->definitionResolver->resolve($definition);

        return $instance;
    }

    /**
     * Call the given function using the given parameters.
     *
     * Missing parameters will be resolved from the container.
     *
     * @param callable $callable   Function to call.
     * @param array    $parameters Parameters to use. Can be indexed by the parameter names
     *                             or not indexed (same order as the parameters).
     *                             The array can also contain DI definitions, e.g. DI\get().
     *
     * @return mixed Result of the function.
     */
    public function call($callable, array $parameters = [])
    {
        return $this->getInvoker()->call($callable, $parameters);
    }

    /**
     * Define an object or a value in the container.
     *
     * @param string $name Entry name
     * @param mixed|DefinitionHelper $value Value, use definition helpers to define objects
     */
    public function set(string $name, $value)
    {
        if ($value instanceof DefinitionHelper) {
            $value = $value->getDefinition($name);
        } elseif ($value instanceof \Closure) {
            $value = new FactoryDefinition($name, $value);
        }

        if ($value instanceof ValueDefinition) {
            $this->resolvedEntries[$name] = $value->getValue();
        } elseif ($value instanceof Definition) {
            $value->setName($name);
            $this->setDefinition($name, $value);
        } else {
            $this->resolvedEntries[$name] = $value;
        }
    }

    /**
     * Get defined container entries.
     *
     * @return string[]
     */
    public function getKnownEntryNames() : array
    {
        $entries = array_unique(array_merge(
            array_keys($this->definitionSource->getDefinitions()),
            array_keys($this->resolvedEntries)
        ));
        sort($entries);

        return $entries;
    }

    /**
     * Get entry debug information.
     *
     * @param string $name Entry name
     *
     * @throws InvalidDefinition
     * @throws NotFoundException
     */
    public function debugEntry(string $name) : string
    {
        $definition = $this->definitionSource->getDefinition($name);
        if ($definition instanceof Definition) {
            return (string) $definition;
        }

        if (array_key_exists($name, $this->resolvedEntries)) {
            return $this->getEntryType($this->resolvedEntries[$name]);
        }

        throw new NotFoundException("No entry or class found for '$name'");
    }

    /**
     * Get formatted entry type.
     *
     * @param mixed $entry
     */
    private function getEntryType($entry) : string
    {
        if (is_object($entry)) {
            return sprintf("Object (\n    class = %s\n)", get_class($entry));
        }

        if (is_array($entry)) {
            return preg_replace(['/^array \(/', '/\)$/'], ['[', ']'], var_export($entry, true));
        }

        if (is_string($entry)) {
            return sprintf('Value (\'%s\')', $entry);
        }

        if (is_bool($entry)) {
            return sprintf('Value (%s)', $entry === true ? 'true' : 'false');
        }

        return sprintf('Value (%s)', is_scalar($entry) ? $entry : ucfirst(gettype($entry)));
    }

    /**
     * Resolves a definition.
     *
     * Checks for circular dependencies while resolving the definition.
     *
     * @throws DependencyException Error while resolving the entry.
     * @return mixed
     */
    private function resolveDefinition(Definition $definition, array $parameters = [])
    {
        $entryName = $definition->getName();

        // Check if we are already getting this entry -> circular dependency
        if (isset($this->entriesBeingResolved[$entryName])) {
            throw new DependencyException("Circular dependency detected while trying to resolve entry '$entryName'");
        }
        $this->entriesBeingResolved[$entryName] = true;

        // Resolve the definition
        try {
            $value = $this->definitionResolver->resolve($definition, $parameters);
        } finally {
            unset($this->entriesBeingResolved[$entryName]);
        }

        return $value;
    }

    protected function setDefinition(string $name, Definition $definition)
    {
        // Clear existing entry if it exists
        if (array_key_exists($name, $this->resolvedEntries)) {
            unset($this->resolvedEntries[$name]);
        }
        $this->fetchedDefinitions = []; // Completely clear this local cache

        $this->definitionSource->addDefinition($definition);
    }

    private function getInvoker() : InvokerInterface
    {
        if (! $this->invoker) {
            $parameterResolver = new ResolverChain([
                new DefinitionParameterResolver($this->definitionResolver),
                new NumericArrayResolver,
                new AssociativeArrayResolver,
                new DefaultValueResolver,
                new TypeHintContainerResolver($this->delegateContainer),
            ]);

            $this->invoker = new Invoker($parameterResolver, $this);
        }

        return $this->invoker;
    }

    private function createDefaultDefinitionSource() : SourceChain
    {
        $source = new SourceChain([new ReflectionBasedAutowiring]);
        $source->setMutableDefinitionSource(new DefinitionArray([], new ReflectionBasedAutowiring));

        return $source;
    }
}