PHP Reflection
**************

.[perex]
[api:Nette\Utils\Reflection] is a static class providing useful functions for PHP reflection. Its purpose is to address shortcomings in native reflection classes and unify behavior across different PHP versions.

Installation:

```shell
composer require nette/utils
```

All examples assume the following class alias is defined:

```php
use Nette\Utils\Reflection;
```


areCommentsAvailable(): bool .[method]
--------------------------------------

Checks if reflection has access to PHPdoc comments. Comments might be unavailable due to opcode caching, see for example the [opcache.save-comments|https://www.php.net/manual/en/opcache.configuration.php#ini.opcache.save-comments] directive.


expandClassName(string $name, ReflectionClass $context): string .[method]
-------------------------------------------------------------------------

Expands the class name `$name` to its fully qualified name within the context of the class `$context`, considering its namespace and defined aliases. Essentially, it determines how the PHP parser would interpret `$name` if it were written inside the body of the `$context` class.

```php
namespace Foo;
use Bar;

class DemoClass
{
	// new Bar, new Baz
}

$context = new ReflectionClass(Foo\DemoClass::class);
Reflection::expandClassName('Bar', $context); // 'Bar'
Reflection::expandClassName('Baz', $context); // 'Foo\Baz'
```


getMethodDeclaringMethod(ReflectionMethod $method): ReflectionMethod .[method]
------------------------------------------------------------------------------

Returns the reflection of the method that contains the actual declaration of `$method`. Usually, a method is its own declaration, but the method body might originate from a trait and potentially under a different name.

Since PHP doesn't provide sufficient information to determine the true declaration reliably, Nette uses its own heuristics, which **should be** reliable.

```php
trait DemoTrait
{
	function foo()
	{
	}
}


class DemoClass
{
	use DemoTrait {
		DemoTrait::foo as foo2;
	}
}


$method = new ReflectionMethod('DemoClass::foo2');
Reflection::getMethodDeclaringMethod($method); // ReflectionMethod('DemoTrait::foo')
```


getParameterDefaultValue(ReflectionParameter $param) .[method]
--------------------------------------------------------------

Returns the default value of `$param` in a function or method. If it is a constant, it returns its value. If the parameter does not have a default value or the constant cannot be resolved, it throws `ReflectionException`.

```php
class DemoClass
{
	function foo($param = PDO::FETCH_BOTH)
	{
	}
}

$method = new ReflectionMethod('DemoClass::foo');
Reflection::getParameterDefaultValue($method->getParameters()[0]);
```


getParameterType(ReflectionParameter $param): ?string .[method]
---------------------------------------------------------------

Returns the type of `$param` in a function or method and normalizes `self` and `parent` to the actual class names. If the parameter does not have a type, it returns `null`.

```php
class DemoClass
{
	function foo(self $param)
	{
	}
}

$method = new ReflectionMethod('DemoClass::foo');
Reflection::getReturnType($method->getParameters()[0]); // 'DemoClass'
```


getPropertyDeclaringClass(ReflectionProperty $prop): ReflectionClass .[method]
------------------------------------------------------------------------------

Returns the reflection of the class or trait that contains the declaration of the property `$prop`. The property might be declared within a trait.

Since PHP doesn't provide sufficient information to determine the true declaration reliably, Nette uses its own heuristics, which **are not** fully reliable.

```php
trait DemoTrait
{
	public $foo;
}


class DemoClass
{
	use DemoTrait;
}

$prop = new ReflectionProperty(DemoClass::class, 'foo');
Reflection::getPropertyDeclaringClass($prop); // ReflectionClass('DemoTrait')
```


getReturnType(ReflectionFunctionAbstract $func): ?string .[method]
------------------------------------------------------------------

Returns the type of return value of function or method `$func` and normalizes `self`, `static`, and `parent` to actual class names. If the function does not have a return type, it returns `null`.

```php
class DemoClass
{
	function foo(): self
	{
	}
}

$method = new ReflectionMethod('DemoClass::foo');
Reflection::getReturnType($method); // 'DemoClass'
```


isBuiltinType(string $type): bool .[method]
-------------------------------------------

Checks if `$type` is a PHP built-in type. Otherwise, it's considered a class name.

```php
Reflection::isBuiltinType('string'); // true
Reflection::isBuiltinType('Foo');    // false
```


toString($reflection): string .[method]
---------------------------------------

Converts a reflection to a string.

```php
$func = new ReflectionFunction('func');
echo Reflection::toString($func); // 'func'

$class = new ReflectionClass('DemoClass');
echo Reflection::toString($class); // 'DemoClass'

$method = new ReflectionMethod('DemoClass', 'foo');
echo Reflection::toString($method); // 'DemoClass::foo'

$param = new ReflectionParameter(['DemoClass', 'foo'], 'param');
echo Reflection::toString($param); // '$param in DemoClass::foo()'

$prop = new ReflectionProperty('DemoClass', 'foo');
echo Reflection::toString($prop); // 'DemoClass::$foo'
```