Question

I have an associative array in the following form:

$params = array(
    'paramName_4'=>'param_4', 
    'paramName_2'=>'param_2',
    // ...,
    'paramName_6'=>'param_6',
); 

and I also have a function myFunction defined as:

public function myFunction($paramName_1, $paramName_2, $paramName_3, ....);

Does a a “parsing” function exist in PHP so that I can call function myFunction by matching the parameters (even if they are not sorted wrt the myFunction‘s parameter sequence)? In other words, can I do

my_magic(__NAMESPACE__.'\\myFunction', $params);

Does this “magic” function does exist? If not, how can I implement it?

Answer 1

You can implement it using reflection. Here’s how:

// The input is the array of arguments and the function name
$arguments = array(....);
$functionName = __NAMESPACE__.'\\myFunction';

$reflector = new \ReflectionFunction($functioName);
$params = $reflector->getParameters();
$values = array();

foreach ($params as $param) {
    $name = $param->getName();
    $isArgumentGiven = array_key_exists($name, $arguments);
    if (!$isArgumentGiven && !$param->isDefaultValueAvailable() {
        die ("Parameter $name is mandatory but was not provided");
    }

    $values[$param->getPosition()] =
        $isArgumentGiven ? $arguments[$name] : $param->getDefaultValue();
}

// You can now call the function:
call_user_func($functionName, $values);