How do I get the type of constructor parameter via reflection?

Question

I'm using type hinting on my constructor parameter list like so:

public function __construct(FooRepository $repository)

Is there a way to use the PHP Reflection API to get the hinted type? In other words, I want a reflection function that I can call to somehow get back the string "FooRepository". I've tried getting the constructor via reflection and then getting the parameters if the constructor, but I don't see anything that will give me the string of the hinted type.

Answer 1

Try this out.

class Foo {
    public function __construct(Bar $test) {
    }
}

class Bar {
    public function __construct() {
    }
}

$reflection = new ReflectionClass('Foo');
$params = $reflection->getConstructor()->getParameters();
foreach ($params AS $param) {
    echo $param->getClass()->name . '<br>';
}

Answer 2

Check out PHP 5.4

They are planning to get out PHP 5.4 this year, which will have the reflection method (current in the dev builds) of parameter->getHint()

However, until 5.4 goes GA, I am using ReflectionClass::getDocComment()

For example, you can specify it in @param.

// Adapted from meager's example
class Bar {}

class Foo {
    /**
    * @param MyType $value
    * @param array $value2
    */
    function __construct(Bar $value, array $value2) {
    }
}

// Regex
function getHint( $docComment, $varName ) {
    $matches = array();
    $count = preg_match_all('/@param[\t\s]*(?P<type>[^\t\s]*)[\t\s]*\$(?P<name>[^\t\s]*)/sim', $docComment, $matches);
    if( $count>0 ) {
        foreach( $matches['name'] as $n=>$name ) {
            if( $name == $varName ) {
                return $matches['type'][$n];
            }
        }
    }
    return null;
}

$reflection = new ReflectionClass('Foo');
$constructor= $reflection->getConstructor();
$docComment = $constructor->getDocComment();
$params = $constructor->getParameters();
foreach ($params AS $param) {
    $name = $param->getName();
    echo $name ." is ";
    //echo $param->getHint()."\n"; // in PHP 5.4
    echo getHint($docComment, $name)."\n"; // work around
}

Output:

value is MyType
value2 is array

Answer 3

Are you trying to get the hinted type, or the actual type? I can't see why you could want to get the hinted type, as you know it is 'FooRepository' or PHP would have raised an error.

You can get the actual type via get_class and you can also find out if a object inherits from a given class with ReflectionClass::isSubclassOf.