<?php
declare(strict_types=1);
namespace DI\Definition\Source;
use DI\Attribute\Inject;
use DI\Attribute\Injectable;
use DI\Definition\Exception\InvalidAttribute;
use DI\Definition\ObjectDefinition;
use DI\Definition\ObjectDefinition\MethodInjection;
use DI\Definition\ObjectDefinition\PropertyInjection;
use DI\Definition\Reference;
use InvalidArgumentException;
use ReflectionClass;
use ReflectionMethod;
use ReflectionNamedType;
use ReflectionParameter;
use ReflectionProperty;
use Throwable;
/**
* Provides DI definitions by reading PHP 8 attributes such as #[Inject] and #[Injectable].
*
* This source automatically includes the reflection source.
*
* @author Matthieu Napoli <[email protected]>
*/
class AttributeBasedAutowiring implements DefinitionSource, Autowiring
{
/**
* @throws InvalidAttribute
*/
public function autowire(string $name, ObjectDefinition $definition = null) : ObjectDefinition|null
{
$className = $definition ? $definition->getClassName() : $name;
if (!class_exists($className) && !interface_exists($className)) {
return $definition;
}
$definition = $definition ?: new ObjectDefinition($name);
$class = new ReflectionClass($className);
$this->readInjectableAttribute($class, $definition);
// Browse the class properties looking for annotated properties
$this->readProperties($class, $definition);
// Browse the object's methods looking for annotated methods
$this->readMethods($class, $definition);
return $definition;
}
/**
* {@inheritdoc}
* @throws InvalidAttribute
* @throws InvalidArgumentException The class doesn't exist
*/
public function getDefinition(string $name) : ObjectDefinition|null
{
return $this->autowire($name);
}
/**
* Autowiring cannot guess all existing definitions.
*/
public function getDefinitions() : array
{
return [];
}
/**
* Browse the class properties looking for annotated properties.
*/
private function readProperties(ReflectionClass $class, ObjectDefinition $definition) : void
{
foreach ($class->getProperties() as $property) {
if ($property->isStatic()) {
continue;
}
$this->readProperty($property, $definition);
}
// Read also the *private* properties of the parent classes
/** @noinspection PhpAssignmentInConditionInspection */
while ($class = $class->getParentClass()) {
foreach ($class->getProperties(ReflectionProperty::IS_PRIVATE) as $property) {
if ($property->isStatic()) {
continue;
}
$this->readProperty($property, $definition, $class->getName());
}
}
}
/**
* @throws InvalidAttribute
*/
private function readProperty(ReflectionProperty $property, ObjectDefinition $definition, ?string $classname = null) : void
{
// Look for #[Inject] attribute
try {
$attribute = $property->getAttributes(Inject::class)[0] ?? null;
if (! $attribute) {
return;
}
/** @var Inject $inject */
$inject = $attribute->newInstance();
} catch (Throwable $e) {
throw new InvalidAttribute(sprintf(
'#[Inject] annotation on property %s::%s is malformed. %s',
$property->getDeclaringClass()->getName(),
$property->getName(),
$e->getMessage()
), 0, $e);
}
// Try to #[Inject("name")] or look for the property type
$entryName = $inject->getName();
// Try using typed properties
$propertyType = $property->getType();
if ($entryName === null && $propertyType instanceof ReflectionNamedType) {
if (! class_exists($propertyType->getName()) && ! interface_exists($propertyType->getName())) {
throw new InvalidAttribute(sprintf(
'#[Inject] found on property %s::%s but unable to guess what to inject, the type of the property does not look like a valid class or interface name',
$property->getDeclaringClass()->getName(),
$property->getName()
));
}
$entryName = $propertyType->getName();
}
if ($entryName === null) {
throw new InvalidAttribute(sprintf(
'#[Inject] found on property %s::%s but unable to guess what to inject, please add a type to the property',
$property->getDeclaringClass()->getName(),
$property->getName()
));
}
$definition->addPropertyInjection(
new PropertyInjection($property->getName(), new Reference($entryName), $classname)
);
}
/**
* Browse the object's methods looking for annotated methods.
*/
private function readMethods(ReflectionClass $class, ObjectDefinition $objectDefinition) : void
{
// This will look in all the methods, including those of the parent classes
foreach ($class->getMethods(ReflectionMethod::IS_PUBLIC) as $method) {
if ($method->isStatic()) {
continue;
}
$methodInjection = $this->getMethodInjection($method);
if (! $methodInjection) {
continue;
}
if ($method->isConstructor()) {
$objectDefinition->completeConstructorInjection($methodInjection);
} else {
$objectDefinition->completeFirstMethodInjection($methodInjection);
}
}
}
private function getMethodInjection(ReflectionMethod $method) : ?MethodInjection
{
// Look for #[Inject] attribute
$attribute = $method->getAttributes(Inject::class)[0] ?? null;
if ($attribute) {
/** @var Inject $inject */
$inject = $attribute->newInstance();
$annotationParameters = $inject->getParameters();
} elseif ($method->isConstructor()) {
// #[Inject] on constructor is implicit, we continue
$annotationParameters = [];
} else {
return null;
}
$parameters = [];
foreach ($method->getParameters() as $index => $parameter) {
$entryName = $this->getMethodParameter($index, $parameter, $annotationParameters);
if ($entryName !== null) {
$parameters[$index] = new Reference($entryName);
}
}
if ($method->isConstructor()) {
return MethodInjection::constructor($parameters);
}
return new MethodInjection($method->getName(), $parameters);
}
/**
* @return string|null Entry name or null if not found.
*/
private function getMethodParameter(int $parameterIndex, ReflectionParameter $parameter, array $annotationParameters) : ?string
{
// Let's check if this parameter has an #[Inject] attribute
$attribute = $parameter->getAttributes(Inject::class)[0] ?? null;
if ($attribute) {
/** @var Inject $inject */
$inject = $attribute->newInstance();
return $inject->getName();
}
// #[Inject] has definition for this parameter (by index, or by name)
if (isset($annotationParameters[$parameterIndex])) {
return $annotationParameters[$parameterIndex];
}
if (isset($annotationParameters[$parameter->getName()])) {
return $annotationParameters[$parameter->getName()];
}
// Skip optional parameters if not explicitly defined
if ($parameter->isOptional()) {
return null;
}
// Look for the property type
$parameterType = $parameter->getType();
if ($parameterType instanceof ReflectionNamedType && !$parameterType->isBuiltin()) {
return $parameterType->getName();
}
return null;
}
/**
* @throws InvalidAttribute
*/
private function readInjectableAttribute(ReflectionClass $class, ObjectDefinition $definition) : void
{
try {
$attribute = $class->getAttributes(Injectable::class)[0] ?? null;
if (! $attribute) {
return;
}
$attribute = $attribute->newInstance();
} catch (Throwable $e) {
throw new InvalidAttribute(sprintf(
'Error while reading #[Injectable] on %s: %s',
$class->getName(),
$e->getMessage()
), 0, $e);
}
if ($attribute->isLazy() !== null) {
$definition->setLazy($attribute->isLazy());
}
}
}