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Reflection

PHPStan has its own reflection layer for asking details about functions, classes, properties, methods, and constants.

Various reflection objects can be obtained either on PHPStan\Type\Type implementations (see type system), or on PHPStan\Reflection\ReflectionProvider object by asking for it in the constructor of your extension:

private ReflectionProvider $reflectionProvider;

public function __construct(
ReflectionProvider $reflectionProvider
)
{
$this->reflectionProvider = $reflectionProvider;
}

Functions #

There are three relevant methods about functions on ReflectionProvider:

  • public function hasFunction(PhpParser\Node\Name $nameNode, ?PHPStan\Analyser\Scope $scope): bool
  • public function getFunction(PhpParser\Node\Name $nameNode, ?PHPStan\Analyser\Scope $scope): FunctionReflection
  • public function resolveFunctionName(PhpParser\Node\Name $nameNode, ?PHPStan\Analyser\Scope $scope): ?string

These methods need Scope because when calling function foo(), PHP first checks whether function CurrentNamespace\foo exists, and if it doesn’t, it looks for function foo in the global namespace.

The getFunction method returns PHPStan\Reflection\FunctionReflection which can be used to get information about the function.

FunctionReflection doesn’t directly contain parameters and return types, but they can be accessed through the getVariants(): ParametersAcceptor[] method. That’s because some built-in PHP functions have multiple variants, like strtok or implode.

If you have the PhpParser\Node\Expr\FuncCall expression, you can obtain the right variant by using ParametersAcceptorSelector:

$variant = PHPStan\Reflection\ParametersAcceptorSelector::selectFromArgs(
$scope,
$funcCall->args,
$functionReflection->getVariants()
);
$parameters = $variant->getParameters();
$returnType = $variant->getReturnType();

Global constants #

There are three relevant methods about global constants on ReflectionProvider:

  • public function hasConstant(PhpParser\Node\Name $nameNode, ?PHPStan\Analyser\Scope $scope): bool
  • public function getConstant(PhpParser\Node\Name $nameNode, ?PHPStan\Analyser\Scope $scope): GlobalConstantReflection
  • public function resolveConstantName(PhpParser\Node\Name $nameNode, ?PHPStan\Analyser\Scope $scope): ?string

These methods need Scope because when accessing global constant FOO, PHP first checks whether constant CurrentNamespace\FOO exists, and if it doesn’t, it looks for constant FOO in the global namespace.

The getConstant method returns PHPStan\Reflection\GlobalConstantReflection which can be used to get information about the constant like the value type with the getValueType(): Type method.

Classes #

The PHPStan\Reflection\ClassReflection can be obtained using the getClass() method on ReflectionProvider. It’s recommended to first check that the class exists using the hasClass() method.

ClassReflection objects represent not only classes, but also interfaces and traits. You can differentiate between them by asking isClass(), isInterface(), and isTrait().

ClassReflection can be used to query information about extended parent classes, implemented interfaces, and used traits:

  • public function getParentClass(): self|false
  • public function getInterfaces(): self[]
  • public function getTraits(): self[]

If you want to get some information that isn’t available on ClassReflection, you can get the built-in ReflectionClass instance [1] with the getNativeReflection(): \ReflectionClass method.

Properties #

Property reflections can be obtained by using these methods on ClassReflection:

  • public function hasProperty(string $propertyName): bool
  • public function getProperty(string $propertyName, PHPStan\Analyser\Scope $scope): PropertyReflection

Class reflection works closely with class reflection extensions to also return information about magically implemented properties using __get() and __set(). If you want to only get information about native properties with no regard to __get() and __set(), use ClassReflection::hasNativeProperty() and ClassReflection::getNativeProperty() instead of ClassReflection::hasProperty() and ClassReflection::getProperty().

Property reflections can also be obtained using methods on PHPStan\Type\Type. See type system for more details.

The returned PropertyReflection object can be used to ask about property’s type, visibility, declaring class, and PHPDoc.

Methods #

Method reflections can be obtained by using these methods on ClassReflection:

  • public function hasMethod(string $methodName): bool
  • public function getMethod(string $methodName, PHPStan\Analyser\Scope $scope): MethodReflection

Class reflection works closely with class reflection extensions to also return information about magically implemented methods using __call() and __callStatic(). If you want to only get information about native methods with no regard to __call() and __callStatic(), use ClassReflection::hasNativeMethod() and ClassReflection::getNativeMethod() instead of ClassReflection::hasMethod() and ClassReflection::getMethod().

Method reflections can also be obtained using methods on PHPStan\Type\Type. See type system for more details.

The returned MethodReflection object can be used to ask about method’s visibility, declaring class, PHPDoc, etc.

MethodReflection doesn’t directly contain parameters and return types, but they can be accessed through the getVariants(): ParametersAcceptor[] method. That’s because some built-in PHP methods have multiple variants, like PDO::query().

If you have the PhpParser\Node\Expr\MethodCall expression, you can obtain the right variant by using ParametersAcceptorSelector:

$variant = PHPStan\Reflection\ParametersAcceptorSelector::selectFromArgs(
$scope,
$methodCall->args,
$methodReflection->getVariants()
);
$parameters = $variant->getParameters();
$returnType = $variant->getReturnType();

Class constants #

Class constant reflections can be obtained by using these methods on ClassReflection:

  • public function hasConstant(string $name): bool
  • public function getConstant(string $name): ConstantReflection

Class constant reflections can also be obtained using methods on PHPStan\Type\Type. See type system for more details.

The returned ConstantReflection can be used to ask about constant’s visibility, declaring class, PHPDoc, and the value type with the getValueType(): Type method.

Retrieving custom PHPDocs #

All information that PHPStan itself works with (like parameter types) is already available directly as methods on reflection objects.

If you want to write custom logic using PHPDoc tags that are unknown to PHPStan internals, you can directly access the PHPDoc’s abstract syntax tree that’s parsed and represented with phpstan/phpdoc-parser library.

Accessing the PHPDoc is a matter of getting the PHPDoc’s string that can look for example like /** @var Foo */ - reflection objects described in this article have getDocComment(): ?string method.

Alternatively, you can obtain the PHPDoc’s string from the source code AST. All nodes have the getDocComment(): ?PhpParser\Comment\Doc method.

Getting the PHPDoc’s AST with PHPStan\Type\FileTypeMapper by asking for the object through your extension’s constructor:

private FileTypeMapper $fileTypeMapper;

public function __construct(FileTypeMapper $fileTypeMapper)
{
$this->fileTypeMapper = $fileTypeMapper;
}

FileTypeMapper has getResolvedPhpDoc method:

public function getResolvedPhpDoc(
string $fileName,
?string $className,
?string $traitName,
?string $functionName,
string $docComment
): ResolvedPhpDocBlock

Beside the PHPDoc’s string itself, you also need to provide the location of the PHPDoc. The call typically looks like this:

$resolvedPhpDoc = $this->fileTypeMapper->getResolvedPhpDoc(
$scope->getFile(),
$scope->isInClass() ? $scope->getClassReflection()->getName() : null,
$scope->isInTrait() ? $scope->getTraitReflection()->getName() : null,
$function !== null ? $function->getName() : null,
$docComment
);

It returns the ResolvedPhpDocBlock object. The phpstan/phpdoc-parser AST can be obtained by calling getPhpDocNodes(): PhpDocNode[] method. The whole PHPDoc is represented by a single root node. So why it returns an array of nodes? Because PHPStan merges PHPDocs from overriden methods to get the complete picture, so all of these nodes are available as a returned value from the getPhpDocNodes() method.


  1. In some cases you’ll get the Adapter implementation instead from BetterReflection because of the hybrid approach to static reflection. But they’re compatible. ↩︎

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